WO2016194197A1 - Power conversion device - Google Patents
Power conversion device Download PDFInfo
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- WO2016194197A1 WO2016194197A1 PCT/JP2015/066203 JP2015066203W WO2016194197A1 WO 2016194197 A1 WO2016194197 A1 WO 2016194197A1 JP 2015066203 W JP2015066203 W JP 2015066203W WO 2016194197 A1 WO2016194197 A1 WO 2016194197A1
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- WIPO (PCT)
- Prior art keywords
- voltage
- overvoltage
- circuit
- state
- capacitor
- Prior art date
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/16—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for capacitors
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/145—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means
- H02M7/155—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only
Definitions
- the present invention relates to a power conversion device that is mounted on home appliances such as an air conditioner and performs a converter operation for converting AC power into DC power, and more particularly to a power conversion device including an overvoltage protection circuit.
- an overvoltage protection circuit for home appliances such as an air conditioner
- a 200V power supply is accidentally applied to a 100V power supply home appliance
- the voltage of the smoothing capacitor that smoothes the DC power obtained by rectifying the AC power is detected by the voltage detection circuit, and when the overvoltage state of the smoothing capacitor is detected, the relay switch is switched to switch the load side
- the light-emitting element or buzzer is used to notify the user of the home appliance with light or sound of the overvoltage state of the power supply.
- an overvoltage protection circuit for an engine control unit (ECU) of a vehicle, there is one that actively eliminates an overvoltage state when an overvoltage of an electrolytic capacitor that holds a power supply voltage is detected (for example, Patent Documents). 2).
- this overvoltage protection circuit there is provided a discharging means for monitoring the charging voltage of the electrolytic capacitor charged by the booster circuit by a microcomputer and discharging the electric charge of the electrolytic capacitor when the charging voltage of the electrolytic capacitor exceeds a predetermined withstand voltage.
- the overvoltage state is positively resolved.
- the overvoltage protection circuit described in Patent Document 1 has a function of notifying a user of home appliances of an overvoltage state when an overvoltage is detected, and a function of cutting off the DC power supply to the load side.
- An overvoltage is continuously applied to a circuit such as a rectifier circuit or a voltage detection circuit. For this reason, depending on the withstand voltage characteristics of the circuit components on the power supply side from the relay switch, there is a possibility that component destruction or component failure occurs.
- the overvoltage protection circuit described in Patent Document 2 is provided with a discharging means for discharging the electric charge of the electrolytic capacitor when an overvoltage is detected, the overvoltage state occurs due to a failure of the booster circuit, and the charge amount from the booster circuit is discharged. If the state where the discharge charge amount by the means continues is continued, the overvoltage state is not eliminated even if the discharge means operates, and there is a possibility that circuit components such as an electrolytic capacitor will break down.
- the present invention has been made to solve the above-described problems, and a first object of the present invention is to detect an overvoltage state of a smoothing capacitor that smoothes DC power obtained by converting AC power.
- An object of the present invention is to obtain a power converter capable of protecting a smoothing capacitor and other circuit components from a withstand voltage failure even when an overvoltage state occurs due to a failure of a booster circuit.
- the 2nd objective of this invention is obtaining household appliances, such as an air conditioner provided with the power converter device which has an overvoltage protection function.
- a power converter includes a first rectifier circuit that rectifies an AC voltage of an AC power supply and outputs a DC voltage, and converts a DC voltage output of the first rectifier circuit to output a converted DC voltage.
- a converter main circuit a main circuit capacitor for smoothing a DC voltage output of the converter main circuit, a first opening / closing means provided in an AC voltage path between the AC power source and the first rectifier circuit, A second switching means and a backflow prevention diode connected in series between the AC power supply side terminal of the first switching means and the positive terminal of the main circuit capacitor; and a capacitor, which rectifies the AC voltage of the AC power supply.
- a second rectifier circuit that outputs a DC voltage; an overvoltage detection circuit that detects an overvoltage state based on the DC voltage output from the second rectifier circuit; and the adjustment circuit that detects the overvoltage state when the overvoltage detection circuit detects the overvoltage state.
- a discharge circuit for discharging a charge of a capacitor of the circuit; and a control means for controlling the first opening and closing means and the second opening and closing means based on an overvoltage state detected by the overvoltage detection circuit, the control means comprising: When the overvoltage state continues for a predetermined time or more, the first opening / closing means and the second opening / closing means in the closed state are opened.
- the power conversion device of the present invention includes the discharge circuit for discharging the electric charge of the capacitor of the rectifier circuit and the control means for controlling the first open / close means and the second open / close means,
- the voltage can be suppressed to a voltage level that does not exceed the component breakdown voltage, and circuit components including the converter main circuit can be protected from component failure due to overvoltage.
- the figure which shows the electric current path (when the power supply voltage phase is positive) when the operation mode is the startup (1) mode The figure which shows the electric current path (when the power supply voltage phase is negative) when the operation mode is the startup (1) mode
- the figure which shows the electric current path (the case where the power supply voltage phase is positive) when the operation mode is the reactive power reduction mode Diagram showing the operation of the overvoltage protection circuit (when the microcomputer did not detect the overvoltage continuation state) Partial diagram showing the operation of the overvoltage protection circuit (when the microcomputer did not detect the overvoltage continuation state)
- Microcomputer control operation flow chart The figure which shows the electric current path
- FIG. 1 shows a system configuration including an air conditioner equipped with the power conversion device of the present embodiment.
- the components normally provided in the air conditioner such as a heat exchanger and a refrigerant pipe are omitted as appropriate.
- This system is provided on an outdoor unit 1 and an indoor unit 2 of an air conditioner, an AC power source (AC) 3 that supplies AC power to the outdoor unit 1, and a power line that connects the AC power source 3 and the outdoor unit 1. And a breaker (BR) 4.
- AC AC power source
- BR breaker
- a power supply line from the AC power supply 3 is connected to the power supply side terminals of the noise filter 5 and the noise filter 6 via the breaker 4.
- the indoor unit 2 is connected to the load side terminal of the noise filter 6.
- the AC power of the AC power supply 3 is supplied to the indoor unit 2 via the noise filter 6 of the outdoor unit 1, and the converter main unit (described later) inside the outdoor unit 1 is connected via the noise filter 5. It is also supplied to a power converter including a circuit and an inverter main circuit.
- One end of a load side terminal of the noise filter 5 is connected to one end of a relay (RL) 7 as a first opening / closing means, and noise is connected between the other end of the relay 7 and the other end of the load side terminal of the noise filter 5.
- a removal capacitor 8 is connected. Both ends of the capacitor 8 are connected to a power supply side terminal of a full-wave rectifier circuit (DB) 9 constituted by a diode bridge as a first rectifier circuit.
- the full-wave rectifier circuit 9 rectifies the AC voltage supplied from the AC power supply 3 and outputs a DC voltage. Since the relay 7 is provided in the AC voltage path between the AC power source 3 and the full-wave rectifier circuit 9, the supply of the AC voltage from the AC power source 3 to the full-wave rectifier circuit 9 is cut off by opening the relay 7. Can do.
- the converter main circuit 10 is connected to the load side terminal of the full-wave rectifier circuit 9.
- the converter main circuit 10 converts the DC voltage output of the full-wave rectifier circuit 9 and outputs the converted DC voltage.
- PFC power factor correction
- a converter main circuit 10 which is a power factor correction (PFC) converter includes reactors 11a and 11b, switching elements 12a and 12b such as MOSFETs (electrolytic effect transistors), backflow prevention diodes 13a and 13b, and a shunt for current detection. It comprises resistors 14a and 14b. Then, using a converter control microcomputer (not shown), the switching elements 12a and 12b are set so that a phase difference occurs in the current flowing through the reactors 11a and 11b based on information such as current values detected by the shunt resistors 14a and 14b. By controlling, a boosted voltage can be obtained as the converter output.
- PFC power factor correction
- a main circuit capacitor 15 is provided on the output side of the converter main circuit 10, and the main circuit capacitor 15 is charged by the converter output voltage, whereby a smoothed DC voltage is generated between the terminals of the main circuit capacitor 15.
- An electrolytic capacitor is suitable as the main circuit capacitor 15.
- PTC Positive Temperature Coefficient
- RL relay
- the other end of the relay 17 is connected to the anode of the backflow prevention diode 18, and the cathode of the backflow prevention diode 18 is connected to the positive terminal of the main circuit capacitor 15.
- the PTC thermistor 16, the relay 17, and the backflow prevention diode 18 are connected in series between the AC power supply side terminal of the relay 7 and the positive terminal of the main circuit capacitor 15, thereby providing a bypass charging path to the main circuit capacitor 15. It is formed.
- the PTC thermistor 16 By providing the PTC thermistor 16 in this bypass charging path, the inrush current when charging the main circuit capacitor 15 can be suppressed.
- a normal resistance element may be used instead of the PTC thermistor 16 according to the device characteristics of circuit components such as the main circuit capacitor 15.
- An inverter main circuit 19 is connected between terminals of the main circuit capacitor 15, and a compressor motor 20 mounted on the outdoor unit 1 is connected to the inverter main circuit 19.
- a brushless DC motor is applied to the motor 20.
- the inverter main circuit 19 rotates the motor 20 by turning on and off the switching elements in the inverter main circuit 19 using an inverter control microcomputer (not shown).
- the inverter main circuit 19 may be constituted by an IPM (Intelligent Power Module).
- One end of another PTC thermistor 21 is connected to the AC power supply side terminal of the relay 7, and the anode of the diode 22 and the cathode of the diode 23 are connected to the other end of the PTC thermistor 21.
- the positive terminal of the smoothing capacitor 24 is connected to the cathode of the diode 22, and the negative terminal of the smoothing capacitor 24 is connected to the anode of the diode 23.
- a diode 22, a diode 23, and a smoothing capacitor 24 constitute a second rectifier circuit that rectifies the AC voltage of the AC power supply 3 and outputs a DC voltage.
- an electrolytic capacitor is suitable. Further, as will be described later, since the voltage of the smoothing capacitor 24 is used when the outdoor unit 1 is started, the capacity of the smoothing capacitor 24 may be smaller than that of the main circuit capacitor 15.
- the DC / DC converter 25 is connected in parallel to the smoothing capacitor 24 and inputs a voltage between terminals of the smoothing capacitor 24 to generate various DC voltages (VCC) used in circuit elements in the outdoor unit 1 such as the microcomputer 26.
- the microcomputer 26 is a microcomputer that controls the overall control of the outdoor unit 1, and it is necessary for the microcomputer 26 to operate in order to start and operate the outdoor unit 1.
- the inter-terminal voltage of the main circuit capacitor 15 is also input to the DC / DC converter 25 via the diode 27 and the diode 28.
- a DC / DC converter 25 having an input voltage range that can correspond to both the voltage between the terminals of the main circuit capacitor 15 and the voltage between the terminals of the smoothing capacitor 24 is used.
- the diodes 27 and 28 also have a role of blocking direct current from the smoothing capacitor 24 toward the main circuit capacitor 15.
- the output voltage detection unit 40 detects the voltage across the terminals of the main circuit capacitor 15, and outputs the detected voltage value to the input port (IN-1) of the microcomputer 26 as a converter output voltage value.
- the overvoltage protection circuit 41 includes an overvoltage detection circuit 41 a that detects an overvoltage state based on the voltage across the smoothing capacitor 24, and a discharge circuit 41 b that discharges the electric charge of the smoothing capacitor 24.
- an overvoltage detection circuit 41 a that detects an overvoltage state based on the voltage across the smoothing capacitor 24, and a discharge circuit 41 b that discharges the electric charge of the smoothing capacitor 24.
- the resistors 29 and 30 are connected in series between the positive terminal of the smoothing capacitor 24 and the ground (GND). As a result, the resistors 29 and 30 divide the voltage between the terminals of the smoothing capacitor 24 to generate the detection voltage Vdet.
- the switching element 32 for detecting an overvoltage state (here, a transistor is used as an example) has a base connected to the interconnection point of the resistors 29 and 30, and a constant voltage diode 31 connected between the emitter and the ground.
- the reference voltage (breakdown voltage) of the constant voltage diode 31 is Vz.
- the base-emitter voltage of the switching element 32 which is a transistor, is Vbe.
- the switching element 32 is turned on when the detection voltage Vdet becomes larger than the sum (Vz + Vbe) of the reference voltage Vz and the emitter-base voltage Vbe, and the detection voltage Vdet is the sum of the reference voltage Vz and the emitter-base voltage Vbe. When it becomes smaller than (Vz + Vbe), it is turned off.
- Resistors 33 and 34 are connected in series between the positive terminal of the smoothing capacitor 24 and the collector of the switching element 32.
- the photodiode of the photocoupler 35 is connected in parallel with the resistor 34.
- the resistors 33 and 34 limit the current flowing through the photodiode of the photocoupler 35.
- One end of the resistor 36 is connected to a direct current power supply (VCC) generated by the DC / DC converter 25, and the other end of the resistor 36 is connected to the collector of the phototransistor of the photocoupler 35.
- VCC direct current power supply
- a capacitor 37 is connected between the collector and emitter of the phototransistor of the photocoupler 35, and the emitter of the phototransistor of the photocoupler 35 is grounded.
- the resistor 36 limits the current flowing through the phototransistor of the photocoupler 35, and the capacitor 37 is for removing noise superimposed on the output of the photocoupler 35. Then, the collector terminal of the phototransistor of the photocoupler 35 is connected to the microcomputer 26.
- the overvoltage detection circuit 41a is configured as described above, when the smoothing capacitor 24 is in an overvoltage state, the switching element 32 is turned on and the photocoupler 35 is turned on, whereby the photocoupler 35 is turned on to a low potential (GND potential). ) Is output to the input port (IN-2) of the microcomputer 26. On the other hand, when the smoothing capacitor 24 is not in an overvoltage state, the switching element 32 is turned off, the photocoupler 35 is turned off, and a high potential (VCC) is output from the photocoupler 35 to the microcomputer 26. In this way, the microcomputer 26 can grasp the overvoltage state of the smoothing capacitor 24.
- VCC high potential
- the microcomputer 26 controls the opening and closing of the relays 7 and 17 based on the grasp of the overvoltage state. The procedure for opening / closing the relays 7 and 17 will be described later. In addition, in order to describe the open / closed state of the breaker 4 and the relays 7 and 17, the open state will be expressed as OFF and the closed state will be expressed as ON.
- the base of the discharge switching element 38 (here, a transistor is taken as an example) is connected to the collector of the switching element 32, and the collector of the switching element 38 is grounded.
- a resistor 39 is connected between the positive terminal of the smoothing capacitor 24 and the emitter of the switching element 38.
- the discharge circuit 41b is configured as described above, when the switching element 32 for detecting an overvoltage state is turned on (when an overvoltage state is detected), the switching element 38 is turned on, and the charge of the smoothing capacitor 24 is changed to the resistance 39. Discharged via. On the other hand, when not in an overvoltage state, since the switching element 32 is in an off state, the switching element 38 is turned off, and the charge of the smoothing capacitor 24 is not discharged.
- FIG. 2 shows an operation timing chart when the outdoor unit 1 is started from a stopped state and shifts to the normal mode and the reactive power reduction mode. Details of each mode will be described later.
- FIG. 3 shows a current path when the voltage phase of the AC power supply 3 is a positive half wave.
- the potential on the breaker 4 side of the AC power supply 3 is higher than the potential on the side not connected to the breaker 4, the voltage phase of the AC power supply 3 is set to “positive”, and the potential on the breaker 4 side is connected to the breaker 4.
- the voltage phase of the AC power supply 3 is defined as “negative” when the potential is lower than the non-side potential.
- the AC power supply 3 ⁇ the noise filter 5 ⁇ the PTC thermistor 21 ⁇ the diode 22 ⁇ the smoothing capacitor 24 ⁇ the diode 28 ⁇ the full wave rectifier circuit 9 ⁇ the noise filter 5 ⁇ the AC power supply 3 A current flows through the path, and the smoothing capacitor 24 is charged.
- the PTC thermistor 21 is provided to suppress an inrush current from the AC power supply 3 to the smoothing capacitor 24 when the outdoor unit 1 is started.
- a DC voltage obtained by rectifying the AC power supply 3 is generated between the terminals of the smoothing capacitor 24.
- the DC voltage is input to the DC / DC converter 25, and the DC / DC converter 25 generates a DC power source for the microcomputer 26, whereby the microcomputer 26 is activated.
- the microcomputer 26 can manage and control the entire outdoor unit 1 by executing a program stored in advance in a storage element (not shown).
- the microcomputer 26 confirms that the converter output voltage (the voltage across the terminals of the main circuit capacitor 15) is equal to or higher than a predetermined voltage threshold based on the detection value of the output voltage detector 40, and then turns the relay 7 on (FIG. 2: Activation (3)). Thereby, a charging path to the main circuit capacitor 15 via the full-wave rectifier circuit 9 and the converter main circuit 10 is formed.
- the voltage threshold value of the converter output voltage described above may be set in consideration of the effect that this inrush current can be suppressed.
- the converter output voltage which is the voltage between the terminals of the main circuit capacitor 15, is supplied to the inverter main circuit 19, and the inverter main circuit 19 rotates and drives the motor 20 using the converter output voltage as a power source. Is executed.
- the overvoltage protection circuit 41 when the outdoor unit 1 is operating in the normal mode will be described.
- the smoothing capacitor 24 is not in an overvoltage state.
- the detection voltage Vdet obtained by dividing the voltage between the terminals of the smoothing capacitor 24 is equal to or less than the sum (Vz + Vbe) of the reference voltage Vz of the constant voltage diode 31 and the emitter-base voltage Vbe of the switching element 32, the switching element.
- Reference numeral 32 denotes an off state, and the photocoupler 35 that transmits the overvoltage detection state to the microcomputer 26 becomes non-conductive. Since a high potential (VCC) is input to the input port of the microcomputer 26, the microcomputer 26 recognizes that the voltage between the terminals of the smoothing capacitor 24 is “normal state (not an overvoltage state)”.
- the microcomputer 26 indicates that the voltage between the terminals of the smoothing capacitor 24 is “normal state (not overvoltage state)”.
- the conditions for determination are (Expression 1), (Expression 2) to (Expression 3).
- Vdet Vc ⁇ R30 / (R29 + R30)
- Vdet Vc ⁇ R30 / (R29 + R30)
- Vc Vc ⁇ R30 + 1 ⁇ (Vz + Vbe
- the microcomputer 26 detects overvoltage based on the determination voltage threshold Vth1 of overvoltage detection defined by (Equation 4).
- Vth1 (R29 / R30 + 1).
- Vz + Vbe Therefore, the determination voltage threshold Vth1 is based on the resistance ratio R29 / R30 determined by the resistance values of the resistors 29 and 30, and the sum (Vz + Vbe) of the reference voltage Vz of the constant voltage diode 31 and the emitter-base voltage Vbe of the switching element 32. Determined.
- the determination voltage threshold value Vth1 may be set so that the determination voltage threshold value Vth1 is smaller than the withstand voltage rating of the electronic components in use including the smoothing capacitor 24.
- the microcomputer 26 recognizes that the inter-terminal voltage of the smoothing capacitor 24 is “normal state (not overvoltage state)”. At the same time, the discharge circuit does not operate and the charge of the smoothing capacitor 24 is not discharged. Further, the microcomputer 26 does not change the on / off states of the relay 7 and the relay 17.
- the microcomputer 26 detects an overvoltage state based on the converter output voltage value detected by the output voltage detection unit 40. At this time, if the determination threshold value Vth2 for overvoltage detection based on the converter output voltage value is set to be smaller than the determination voltage threshold value Vth1 for overvoltage detection based on the signal from the overvoltage detection circuit 41a (that is, Vth2 ⁇ Vth1), the microcomputer 26 detects overvoltage. An overvoltage protection operation can be performed before the circuit detects the overvoltage. Accordingly, it is considered that there are few cases in which the overvoltage detection circuit 41a detects an overvoltage state when operating in the normal mode in practice, and therefore description of the circuit operation in such a case is omitted.
- the reactive power reduction mode is to reduce the reactive current flowing through the capacitor 8 when the operation of the motor 20 in the normal mode is finished and the power supply to the converter main circuit 10 and the inverter main circuit 19 becomes unnecessary. This is an operation mode for reducing reactive power.
- the transition to the reactive power reduction mode is performed by turning off the relay 7 under the control of the microcomputer 26 after a predetermined time has elapsed after the operation of the motor 20 in the normal mode is completed.
- the relay 17 maintains an OFF state (FIG. 2: Reactive power reduction mode).
- the terminal connected to the breaker 4 is defined as the first terminal of the capacitor 8 and the other terminal is defined as the second terminal of the capacitor 8.
- the voltage between the terminals of the capacitor 8 is positive, and when the first terminal of the capacitor 8 is at a lower potential than the second terminal of the capacitor 8.
- the voltage between terminals of the capacitor 8 is defined as negative polarity.
- the first current path in which an overvoltage state occurs between the terminals of the smoothing capacitor 24 is invalid when a positive charge remains at the first terminal of the capacitor 8 and the voltage phase of the AC power supply 3 is negative. It is formed when shifting to the power reduction mode. Specifically, as shown in FIG. 5, AC power supply 3 ⁇ noise filter 5 ⁇ capacitor 8 ⁇ full wave rectifier circuit 9 ⁇ converter main circuit 10 ⁇ diode 27 ⁇ smoothing capacitor 24 ⁇ diode 23 ⁇ PTC thermistor 21 ⁇ noise filter 5 ⁇ Current flows through the path of the AC power source 3.
- the second current path in which an overvoltage state occurs between the terminals of the smoothing capacitor 24 is invalid when negative charge remains in the first terminal of the capacitor 8 and the voltage phase of the AC power supply 3 is positive. It is formed when shifting to the power reduction mode. Specifically, as shown in FIG. 6, the AC power source 3 ⁇ the noise filter 5 ⁇ the PTC thermistor 21 ⁇ the diode 22 ⁇ the smoothing capacitor 24 ⁇ the diode 28 ⁇ the full wave rectifier circuit 9 ⁇ the capacitor 8 ⁇ the noise filter 5 ⁇ the AC power source 3. Current flows through the path.
- the withstand voltage required for the smoothing capacitor 24 is calculated by predefining the maximum residual charge amount of the capacitor 8 and the voltage fluctuation range of the AC power supply 3 that are assumed when the power converter is operated. It is only necessary to select a component that satisfies this pressure resistance characteristic. However, since the withstand voltage characteristics of actually selectable capacitor parts are limited and large voltage fluctuations of the AC power supply 3 deviating from the range specified by the abnormality of the external power supply system or the like can occur. It is difficult to pre-select capacitor components that can cope with the situation.
- FIG. 7 is a diagram showing operation waveforms of each part of the overvoltage protection circuit 41.
- 7A shows the voltage between the terminals of the smoothing capacitor 24, and
- FIGS. 7B and 7C show the on / off states of the switching elements 32 and 38, respectively.
- D is the input voltage of the input port (IN-2) of the microcomputer 26, which is also the collector voltage of the photocoupler 35.
- E and (f) show ON / OFF states of the relays 17 and 7, respectively.
- the relay 17 when operating in the normal mode, the relay 17 is in the off state and the relay 7 is in the on state.
- the relay 7 is in the on state.
- an overvoltage is applied to the smoothing capacitor 24 through the current path shown in FIG. The voltage rises.
- the switching element 32 is turned on. The turn-on means that the switching element shifts from the off state to the on state.
- the discharge switching element 38 is subsequently turned on (time T3), and the photocoupler 35 is also turned on.
- the switching element 38 is turned on, a discharge current flows from the smoothing capacitor 24 via the resistor 39, and the voltage between the terminals of the smoothing capacitor 24 decreases.
- a low potential (GND potential) is input to the input port (IN-2) of the microcomputer 26, and the microcomputer 26 has an overvoltage state between the terminals of the smoothing capacitor 24. Recognize that.
- the switching element 32 is turned off. Note that the turn-off means that the switching element shifts from the on state to the off state.
- the discharge switching element 38 is subsequently turned off (time T5), and the photocoupler 35 is also turned off.
- time T5 time T5
- the switching element 38 is turned off, the flow of the discharge current flowing from the smoothing capacitor 24 via the resistor 39 is stopped, and the decrease in the voltage between the terminals of the smoothing capacitor 24 is also stopped.
- the voltage value between the terminals of the smoothing capacitor 24 at the time when the voltage drop stops depends on the time delay width of turn-off of the switching element 32 and the switching element 38 and the resistance value of the resistor 39. In FIG. 7, the time delays of turning on and turning off the switching element 32 and the switching element 38 are exaggerated for easy explanation.
- FIG. 8 is an enlarged view of a portion where the input voltage of the input port (IN-2) of the microcomputer 26 in FIG. 7 becomes a low potential (GND potential).
- (d) and (f) are the same signal waveforms as those shown in FIG. 7, and (g) shows the sampling timing at which the microcomputer 26 samples the input voltage of the input port (IN-2). Is.
- the microcomputer 26 samples the input voltage of the input port (IN-2) at the cycle Ts.
- the value of the cycle Ts may be set in advance as a part of a processing program executed by the microcomputer 26 in a storage medium (not shown).
- step S2 the input voltage at the input port (IN-2) of the microcomputer 26 is sampled (step S2). Sampling is performed every period Ts. The following processing is processing performed corresponding to one sampling value acquisition.
- n is greater than or equal to Ns (step S6).
- the Ns value may be held in advance in a memory element (not shown) as an overvoltage continuation state determination threshold value, or may be defined in the processing program of the microcomputer 26.
- n ⁇ Ns it means that the sampling voltages for Ns times or more in succession were all at a low potential. Since the input voltage of the input port (IN-2) becomes a low potential when the overvoltage detection circuit 41a detects the overvoltage state, n ⁇ Ns means that the smoothing capacitor 24 of the discharge circuit 41b This means that the overvoltage state has not been resolved for at least (Ns ⁇ 1) ⁇ Ts time despite the discharge being performed.
- the length of time during which such an overvoltage state continues is defined as an overvoltage duration Td.
- the microcomputer 26 determines that the “overvoltage continuation state” when the overvoltage continuation time Td is equal to or longer than (Ns ⁇ 1) ⁇ Ts (step S7).
- the relays 7 and 17 are turned off under the control of the microcomputer 26. If the relays 7 and 17 have already been turned off, the respective relays are kept off (step S8).
- the relays 7 and 17 are turned off to cut off the power from the AC power supply 3, thereby eliminating the overvoltage state. This is an overvoltage elimination operation by software control.
- the occurrence of the overvoltage continuation state may be notified to the user of the power conversion device by a display device (not shown) that the power interruption by the relays 7 and 17 has been performed.
- the microcomputer 26 repeatedly executes the processing of steps S2 to S6 every time the input voltage of the input port (IN-2) is sampled until it is determined as “overvoltage continuation state”.
- the overvoltage continuation time Td since the overvoltage continuation time Td is small, the sampling voltages for the continuous Ns times are not all low potentials, so the microcomputer 26 does not determine that the “overvoltage continuation state”.
- the relays 7 and 17 are already in an off state and the AC power from the AC power supply 3 is cut off. Therefore, the situation in which the microcomputer 26 determines that the “overvoltage continuation state” is not likely to occur. For this reason, even when the voltage of the AC power supply 3 fluctuates instantaneously, the overvoltage state can be resolved only by the hardware operation of the overvoltage protection circuit 41.
- the operation of the outdoor unit 1 is performed by switching the breaker 4 from the off state to the on state.
- the mode is shifted to the “start (1)” state, AC power is supplied to the outdoor unit 1 through the above-described current paths of FIGS. 3 and 4 and the smoothing capacitor 24 is charged.
- the microcomputer 26 is activated by the DC voltage from the DC / DC converter 25.
- FIGS. Current also flows through the path.
- FIG. 10 shows a current path when the voltage phase of the AC power supply 3 is positive
- FIG. 11 shows a current path when the voltage phase of the AC power supply 3 is negative.
- the AC power supply 3 when the voltage phase of the AC power supply 3 is positive, as shown in FIG. 10, the AC power supply 3 ⁇ the noise filter 5 ⁇ the PTC thermistor 16 ⁇ the diode 18 ⁇ the main circuit capacitor 15 ⁇ the full wave rectifier circuit 9 ⁇ noise. A current flows through the path of the filter 5 ⁇ the AC power source 3. As a result, the main circuit capacitor 15 is charged.
- the AC power supply 3 when the voltage phase of the AC power supply 3 is negative, as shown in FIG. 11, the AC power supply 3 ⁇ the noise filter 5 ⁇ the full wave rectifier circuit 9 ⁇ the converter main circuit 10 ⁇ the main circuit capacitor 15 ⁇ the diode 27 ⁇ the smoothing capacitor.
- the converter main circuit 10 has not yet started the step-up operation, and the switching elements 12a and 12b are not driven on / off.
- the switching element 12a is short-circuited, the inside of the switching element 12a becomes conductive.
- a voltage obtained by adding the voltage between the terminals of the main circuit capacitor 15 and the voltage of the AC power supply 3 is applied between the terminals of the smoothing capacitor 24, thereby generating an overvoltage state between the terminals of the smoothing capacitor 24.
- the voltage boosting operation for the smoothing capacitor 24 is repeated every voltage cycle of the AC power supply 3, and the overvoltage state of the smoothing capacitor 24 continues to occur.
- FIGS. 12 and 13 show the operation timing of the overvoltage protection circuit 41 when the operation mode of the outdoor unit 1 transitions from the “start (1)” state to the “start (2)” state, as in FIGS. 7 and 8. It is a thing.
- the relay 17 and the relay 7 are in an off state during operation in the start (1) mode.
- a current flows in the current path shown in FIGS. 10 and 11 corresponding to the voltage phase of the AC power supply 3.
- an overvoltage is applied to the smoothing capacitor 24, and the voltage across the terminals of the smoothing capacitor 24 increases.
- the switching element 32 is turned on.
- the discharge switching element 38 is subsequently turned on (time T13), and the photocoupler 35 is also turned on.
- a discharge current flows from the smoothing capacitor 24 via the resistor 39.
- a low potential (GND potential) is input to the input port (IN-2) of the microcomputer 26, and the microcomputer 26 is in an overvoltage state between the terminals of the smoothing capacitor 24.
- the electric charge of the smoothing capacitor 24 is discharged by the operation of the discharge circuit 41b.
- the step-up operation is repeated in the voltage cycle of the AC power supply 3, and therefore, the smoothing capacitor 24 is shown in FIGS. It is repeatedly charged in the current path. For this reason, the voltage between the terminals of the smoothing capacitor 24 continues to increase.
- the relay 17 is switched from the on state to the off state. Since the relay 7 is in the off state in the start (2) mode, the off state is maintained. In addition, when the relay 7 is in an on state due to a malfunction or the like, the relay 7 is also switched to an off state. When the relay 17 is turned off, the charging path of the smoothing capacitor 24 is interrupted. And the discharge of the smoothing capacitor 24 by the discharge circuit 41b continues, so that the voltage across the terminals of the smoothing capacitor 24 decreases before reaching the withstand voltage level of the component. In this way, it is possible to prevent a component failure due to overvoltage.
- the switching element 32 When the voltage between the terminals of the smoothing capacitor 24 becomes smaller than the determination voltage threshold Vth1 for overvoltage detection (time T15), the switching element 32 is turned off, and then the discharge switching element 38 and the photocoupler 35 are also turned off (time T16). . Thereby, although the input voltage of the input port (IN-2) of the microcomputer 26 changes to a high potential, the microcomputer 26 maintains the relay 17 in the OFF state until the entire air conditioner including the outdoor unit 1 is restarted.
- the microcomputer 26 restarts the entire air conditioner system, thereby restarting the process from the operation mode in the “stop” state. Similarly, after the air conditioner system is restarted, when the microcomputer 26 detects the “overvoltage continuation state”, it restarts again.
- the “overvoltage continuation state” is detected after restarting Nf times continuously, the occurrence of the overvoltage state is not temporary, and there is a high possibility that the converter main circuit 10 is faulty. Stop the startup process.
- the Nf value may be stored in advance in a memory element (not shown) as a system failure determination threshold value or may be defined in the processing program of the microcomputer 26.
- the overvoltage detection circuit 41a detects the overvoltage state even if the voltage between the terminals of the smoothing capacitor 24 becomes an overvoltage state at the time of transition to the reactive power reduction mode or at the time of a short circuit failure of the converter main circuit 10, etc. Since the overvoltage protection circuit 41 is configured so that the circuit 41b discharges the electric charge of the smoothing capacitor 24, the voltage between the terminals of the smoothing capacitor 24 can be suppressed to a voltage level that does not exceed the component breakdown voltage.
- the charging path of the smoothing capacitor 24 and the converter main circuit 10 are turned off by turning off the relay 7 and the relay 17 under the control of the microcomputer 26. Even in such a case, the voltage between the terminals of the smoothing capacitor 24 can be suppressed to a voltage level that does not exceed the component withstand voltage, and the circuit components including the converter main circuit 10 are caused by overvoltage. It can protect against component failure.
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- Protection Of Static Devices (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The purpose of the present invention is to obtain a power conversion device which can protect circuit components from damage due to overvoltage, even in a case where a state of overvoltage has occurred due to component damage. Provided is a power conversion device comprising: an overvoltage detection circuit 41a for detecting an overvoltage state on the basis of the inter-terminal voltage of a smoothing capacitor 24 of a second rectification circuit; a discharge circuit 41b for discharging an electrical charge of the smoothing capacitor 24 when the overvoltage detection circuit 41a has detected an overvoltage state; and a microcomputer 26 for detecting a continuous overvoltage state on the basis of the overvoltage state detected by the overvoltage detection circuit 41a, and controlling a relay 7 and a relay 17.
Description
この発明は、空気調和機等の家電機器に実装され、交流電力を直流電力へ変換するコンバータ動作を行う電力変換装置に関するものであり、特に過電圧保護回路を備えた電力変換装置に関するものである。
The present invention relates to a power conversion device that is mounted on home appliances such as an air conditioner and performs a converter operation for converting AC power into DC power, and more particularly to a power conversion device including an overvoltage protection circuit.
空気調和機等の家電機器の過電圧保護回路として、100V電源仕様の家電機器に誤って200V電源を印可した場合に対処するものがある(例えば、特許文献1参照)。この過電圧保護回路では、交流電力を整流して得た直流電力を平滑する平滑コンデンサの電圧を電圧検出回路で検出し、平滑コンデンサの過電圧状態を検出した際にはリレースイッチを切り替えることにより負荷側への電力供給を遮断するとともに、発光素子やブザーを用いて光や音で家電機器の利用者に電源の過電圧状態を報知するものである。
As an overvoltage protection circuit for home appliances such as an air conditioner, there is one that copes with a case where a 200V power supply is accidentally applied to a 100V power supply home appliance (for example, see Patent Document 1). In this overvoltage protection circuit, the voltage of the smoothing capacitor that smoothes the DC power obtained by rectifying the AC power is detected by the voltage detection circuit, and when the overvoltage state of the smoothing capacitor is detected, the relay switch is switched to switch the load side In addition to shutting off the power supply to the device, the light-emitting element or buzzer is used to notify the user of the home appliance with light or sound of the overvoltage state of the power supply.
また、車両のエンジンコントロールユニット(ECU)の過電圧保護回路として、電源電圧を保持する電解コンデンサの過電圧を検知した際には積極的に過電圧状態を解消するようにしたものがある(例えば、特許文献2参照)。この過電圧保護回路では、昇圧回路により充電される電解コンデンサの充電電圧をマイコンで監視し、電解コンデンサの充電電圧が所定の耐電圧を超えた場合には電解コンデンサの電荷を放電させる放電手段を設けることにより、積極的に過電圧状態を解消するようにしている。
Further, as an overvoltage protection circuit for an engine control unit (ECU) of a vehicle, there is one that actively eliminates an overvoltage state when an overvoltage of an electrolytic capacitor that holds a power supply voltage is detected (for example, Patent Documents). 2). In this overvoltage protection circuit, there is provided a discharging means for monitoring the charging voltage of the electrolytic capacitor charged by the booster circuit by a microcomputer and discharging the electric charge of the electrolytic capacitor when the charging voltage of the electrolytic capacitor exceeds a predetermined withstand voltage. Thus, the overvoltage state is positively resolved.
特許文献1記載の過電圧保護回路は、過電圧検出時に過電圧状態を家電機器の利用者に報知する機能と負荷側への直流電力供給を遮断する機能を有しているものの、リレースイッチより電源側にある整流回路や電圧検出回路等の回路には過電圧が印加され続ける構成になっている。この為、リレースイッチより電源側にある回路部品の耐電圧特性によっては部品破壊若しくは部品不良が起こる可能性がある。
The overvoltage protection circuit described in Patent Document 1 has a function of notifying a user of home appliances of an overvoltage state when an overvoltage is detected, and a function of cutting off the DC power supply to the load side. An overvoltage is continuously applied to a circuit such as a rectifier circuit or a voltage detection circuit. For this reason, depending on the withstand voltage characteristics of the circuit components on the power supply side from the relay switch, there is a possibility that component destruction or component failure occurs.
また、特許文献2記載の過電圧保護回路は、過電圧検出時に電解コンデンサの電荷を放電させる放電手段を設けているものの、過電圧状態が昇圧回路の故障により発生し、昇圧回路からの充電電荷量が放電手段による放電電荷量よりも大きくなる状態が継続した場合には、放電手段が動作しても過電圧状態が解消されず、電解コンデンサ等の回路部品が耐圧故障となる可能性がある。
Moreover, although the overvoltage protection circuit described in Patent Document 2 is provided with a discharging means for discharging the electric charge of the electrolytic capacitor when an overvoltage is detected, the overvoltage state occurs due to a failure of the booster circuit, and the charge amount from the booster circuit is discharged. If the state where the discharge charge amount by the means continues is continued, the overvoltage state is not eliminated even if the discharge means operates, and there is a possibility that circuit components such as an electrolytic capacitor will break down.
この発明は上記のような課題を解決するためになされたものであり、本発明の第1の目的は、交流電力から変換して得た直流電力を平滑する平滑コンデンサの過電圧状態を検出するとともに、過電圧状態が昇圧回路の故障により発生した場合でも、平滑コンデンサ、及びその他の回路構成部品を耐電圧故障から保護することができる電力変換装置を得ることである。また、本発明の第2の目的は、過電圧保護機能を有する電力変換装置を備えた空気調和機等の家電機器を得ることである。
The present invention has been made to solve the above-described problems, and a first object of the present invention is to detect an overvoltage state of a smoothing capacitor that smoothes DC power obtained by converting AC power. An object of the present invention is to obtain a power converter capable of protecting a smoothing capacitor and other circuit components from a withstand voltage failure even when an overvoltage state occurs due to a failure of a booster circuit. Moreover, the 2nd objective of this invention is obtaining household appliances, such as an air conditioner provided with the power converter device which has an overvoltage protection function.
本発明の電力変換装置は、交流電源の交流電圧を整流して直流電圧を出力する第1の整流回路と、前記第1の整流回路の直流電圧出力を変換して変換後の直流電圧を出力するコンバータ主回路と、前記コンバータ主回路の直流電圧出力を平滑する主回路コンデンサと、前記交流電源と前記第1の整流回路間の交流電圧経路に設けられた第1の開閉手段と、前記第1の開閉手段の交流電源側端子と前記主回路コンデンサの正極端子間に直列接続された第2の開閉手段及び逆流防止用ダイオードと、コンデンサを有し、前記交流電源の交流電圧を整流して直流電圧を出力する第2の整流回路と、前記第2の整流回路が出力する直流電圧に基づき過電圧状態を検出する過電圧検出回路と、前記過電圧検出回路が過電圧状態を検出した際に、前記整流回路のコンデンサの電荷を放電する放電回路と、前記過電圧検出回路が検出した過電圧状態に基づき、前記第1の開閉手段及び前記第2の開閉手段を制御する制御手段とを備え、前記制御手段は、前記過電圧状態が所定の時間以上継続した際には、閉状態にある前記第1の開閉手段及び前記第2の開閉手段を開放することを特徴とするものである。
A power converter according to the present invention includes a first rectifier circuit that rectifies an AC voltage of an AC power supply and outputs a DC voltage, and converts a DC voltage output of the first rectifier circuit to output a converted DC voltage. A converter main circuit, a main circuit capacitor for smoothing a DC voltage output of the converter main circuit, a first opening / closing means provided in an AC voltage path between the AC power source and the first rectifier circuit, A second switching means and a backflow prevention diode connected in series between the AC power supply side terminal of the first switching means and the positive terminal of the main circuit capacitor; and a capacitor, which rectifies the AC voltage of the AC power supply. A second rectifier circuit that outputs a DC voltage; an overvoltage detection circuit that detects an overvoltage state based on the DC voltage output from the second rectifier circuit; and the adjustment circuit that detects the overvoltage state when the overvoltage detection circuit detects the overvoltage state. A discharge circuit for discharging a charge of a capacitor of the circuit; and a control means for controlling the first opening and closing means and the second opening and closing means based on an overvoltage state detected by the overvoltage detection circuit, the control means comprising: When the overvoltage state continues for a predetermined time or more, the first opening / closing means and the second opening / closing means in the closed state are opened.
本発明の電力変換装置は、整流回路のコンデンサの電荷を放電する放電回路とともに、第1の開閉手段及び前記第2の開閉手段を制御する制御手段を備えたので、整流回路のコンデンサの端子間電圧が部品耐圧を超えない電圧レベルに抑えることが可能であるとともに、コンバータ主回路を含む回路部品を過電圧による部品故障から保護することができる。
Since the power conversion device of the present invention includes the discharge circuit for discharging the electric charge of the capacitor of the rectifier circuit and the control means for controlling the first open / close means and the second open / close means, The voltage can be suppressed to a voltage level that does not exceed the component breakdown voltage, and circuit components including the converter main circuit can be protected from component failure due to overvoltage.
本発明に係る電力変換装置の実施の形態について、図に基づいて構成及び動作を説明する。図1に本実施の形態の電力変換装置を搭載した空気調和機を含むシステム構成を示す。なお、空気調和機の電力変換装置に関連する部分のみ図示し、熱交換器、冷媒配管等の空気調和機が通常備えている構成部分については適宜省略している。
The configuration and operation of an embodiment of a power converter according to the present invention will be described with reference to the drawings. FIG. 1 shows a system configuration including an air conditioner equipped with the power conversion device of the present embodiment. In addition, only the part relevant to the power converter device of an air conditioner is shown in figure, and the components normally provided in the air conditioner such as a heat exchanger and a refrigerant pipe are omitted as appropriate.
本システムは、空気調和機の室外機1及び室内機2と、室外機1に交流電力を供給する交流電源(AC)3と、交流電源3と室外機1を接続する電源線上に設けられたブレーカ(BR)4とから構成される。
This system is provided on an outdoor unit 1 and an indoor unit 2 of an air conditioner, an AC power source (AC) 3 that supplies AC power to the outdoor unit 1, and a power line that connects the AC power source 3 and the outdoor unit 1. And a breaker (BR) 4.
次に、室外機1内部の電力変換装置の構成を説明する。交流電源3からの電源線はブレーカ4を経由してノイズフィルタ5及びノイズフィルタ6の電源側端子に接続される。ノイズフィルタ6の負荷側端子には室内機2が接続される。ブレーカ4をオン(ON)することにより、交流電源3の交流電力が室外機1のノイズフィルタ6経由で室内機2に供給されるとともに、ノイズフィルタ5経由で室外機1内部の後述するコンバータ主回路やインバータ主回路等を含んだ電力変換装置にも供給される。
Next, the configuration of the power conversion device inside the outdoor unit 1 will be described. A power supply line from the AC power supply 3 is connected to the power supply side terminals of the noise filter 5 and the noise filter 6 via the breaker 4. The indoor unit 2 is connected to the load side terminal of the noise filter 6. By turning on the breaker 4, the AC power of the AC power supply 3 is supplied to the indoor unit 2 via the noise filter 6 of the outdoor unit 1, and the converter main unit (described later) inside the outdoor unit 1 is connected via the noise filter 5. It is also supplied to a power converter including a circuit and an inverter main circuit.
ノイズフィルタ5の負荷側端子の一端には第1の開閉手段であるリレー(RL)7の一端が接続され、リレー7の他端とノイズフィルタ5の負荷側端子の他端の間にはノイズ除去用のコンデンサ8が接続される。コンデンサ8の両端には第1の整流回路であるダイオードブリッジで構成した全波整流回路(DB)9の電源側端子が接続される。全波整流回路9は交流電源3から供給される交流電圧を整流して直流電圧を出力する。リレー7は交流電源3と全波整流回路9間の交流電圧経路に設けられているので、リレー7を開放することで交流電源3から全波整流回路9への交流電圧の供給を遮断することができる。
One end of a load side terminal of the noise filter 5 is connected to one end of a relay (RL) 7 as a first opening / closing means, and noise is connected between the other end of the relay 7 and the other end of the load side terminal of the noise filter 5. A removal capacitor 8 is connected. Both ends of the capacitor 8 are connected to a power supply side terminal of a full-wave rectifier circuit (DB) 9 constituted by a diode bridge as a first rectifier circuit. The full-wave rectifier circuit 9 rectifies the AC voltage supplied from the AC power supply 3 and outputs a DC voltage. Since the relay 7 is provided in the AC voltage path between the AC power source 3 and the full-wave rectifier circuit 9, the supply of the AC voltage from the AC power source 3 to the full-wave rectifier circuit 9 is cut off by opening the relay 7. Can do.
全波整流回路9の負荷側端子にはコンバータ主回路10が接続される。コンバータ主回路10は、全波整流回路9の直流電圧出力を変換して変換後の直流電圧を出力する。ここではコンバータ主回路10として力率改善(PFC)コンバータを用いた場合で説明する。なお、コンバータ主回路10の構成はこれに限定されるものではなく、公知の技術を適用してこれ以外のコンバータ主回路を構成するようにしてもよい。
The converter main circuit 10 is connected to the load side terminal of the full-wave rectifier circuit 9. The converter main circuit 10 converts the DC voltage output of the full-wave rectifier circuit 9 and outputs the converted DC voltage. Here, a case where a power factor correction (PFC) converter is used as the converter main circuit 10 will be described. Note that the configuration of the converter main circuit 10 is not limited to this, and other converter main circuits may be configured by applying a known technique.
力率改善(PFC)コンバータであるコンバータ主回路10は、リアクタ11a,11bと、MOSFET(電解効果トランジスタ)等のスイッチング素子12a,12bと、逆流防止用ダイオード13a,13bと、電流検出用のシャント抵抗14a,14bとで構成される。そして、図示しないコンバータ制御用マイコンを用いて、シャント抵抗14a,14bで検出した電流値等の情報に基づいて、リアクタ11a,11bとに流れる電流に位相差が生じるようにスイッチング素子12a,12bを制御することで、コンバータ出力として昇圧された電圧を得ることができる。コンバータ主回路10の出力側には主回路コンデンサ15が設けられ、コンバータ出力電圧により主回路コンデンサ15が充電されることで、主回路コンデンサ15の端子間に平滑化した直流電圧が生成される。主回路コンデンサ15としては電解コンデンサが好適である。なお、力率改善コンバータの詳細構成については例えば特許公報(特許第5443364号)に開示されているものを利用することができる。
A converter main circuit 10 which is a power factor correction (PFC) converter includes reactors 11a and 11b, switching elements 12a and 12b such as MOSFETs (electrolytic effect transistors), backflow prevention diodes 13a and 13b, and a shunt for current detection. It comprises resistors 14a and 14b. Then, using a converter control microcomputer (not shown), the switching elements 12a and 12b are set so that a phase difference occurs in the current flowing through the reactors 11a and 11b based on information such as current values detected by the shunt resistors 14a and 14b. By controlling, a boosted voltage can be obtained as the converter output. A main circuit capacitor 15 is provided on the output side of the converter main circuit 10, and the main circuit capacitor 15 is charged by the converter output voltage, whereby a smoothed DC voltage is generated between the terminals of the main circuit capacitor 15. An electrolytic capacitor is suitable as the main circuit capacitor 15. In addition, about the detailed structure of a power factor improvement converter, what is disclosed by patent gazette (patent 5443364) can be utilized, for example.
リレー7の交流電源側端子にはPTCサーミスタ16(PTC: Positive Temperature Coefficient)の一端が接続され、PTCサーミスタ16の他端には第2の開閉手段であるリレー(RL)17の一端が接続される。リレー17の他端には逆流防止用ダイオード18のアノードが接続され、逆流防止用ダイオード18のカソードには主回路コンデンサ15の正極端子が接続される。このようにリレー7の交流電源側端子と主回路コンデンサ15の正極端子間にPTCサーミスタ16、リレー17、逆流防止用ダイオード18が直列接続されることで、主回路コンデンサ15へのバイパス充電経路が形成される。このバイパス充電経路にPTCサーミスタ16を設けることで、主回路コンデンサ15を充電する際の突入電流を抑制することができる。なお、主回路コンデンサ15等の回路部品のデバイス特性に応じて、PTCサーミスタ16の代わりに通常の抵抗素子を用いてもよい。また、ダイオード18には全波整流回路9やコンバータ主回路10内のダイオードよりも電流耐量が大きいスペックの素子を用いることが望ましい。
One end of a PTC thermistor 16 (PTC: Positive Temperature Coefficient) is connected to the AC power supply side terminal of the relay 7, and one end of a relay (RL) 17 as a second opening / closing means is connected to the other end of the PTC thermistor 16. The The other end of the relay 17 is connected to the anode of the backflow prevention diode 18, and the cathode of the backflow prevention diode 18 is connected to the positive terminal of the main circuit capacitor 15. Thus, the PTC thermistor 16, the relay 17, and the backflow prevention diode 18 are connected in series between the AC power supply side terminal of the relay 7 and the positive terminal of the main circuit capacitor 15, thereby providing a bypass charging path to the main circuit capacitor 15. It is formed. By providing the PTC thermistor 16 in this bypass charging path, the inrush current when charging the main circuit capacitor 15 can be suppressed. Note that a normal resistance element may be used instead of the PTC thermistor 16 according to the device characteristics of circuit components such as the main circuit capacitor 15. In addition, it is desirable to use an element having a specification with a larger current resistance than the diode in the full-wave rectifier circuit 9 or the converter main circuit 10 for the diode 18.
主回路コンデンサ15の端子間にはインバータ主回路19が接続され、インバータ主回路19には室外機1に搭載される圧縮機のモータ20が接続される。モータ20には例えばブラシレスDCモータが適用される。インバータ主回路19は図示しないインバータ制御用マイコンを用いて、インバータ主回路19内のスイッチング素子をオン・オフ駆動することにより、モータ20を回転駆動する。なお、インバータ主回路19はIPM(Intelligent Power Module)で構成してもよい。
An inverter main circuit 19 is connected between terminals of the main circuit capacitor 15, and a compressor motor 20 mounted on the outdoor unit 1 is connected to the inverter main circuit 19. For example, a brushless DC motor is applied to the motor 20. The inverter main circuit 19 rotates the motor 20 by turning on and off the switching elements in the inverter main circuit 19 using an inverter control microcomputer (not shown). The inverter main circuit 19 may be constituted by an IPM (Intelligent Power Module).
リレー7の交流電源側端子にはもう1つのPTCサーミスタ21の一端が接続され、PTCサーミスタ21の他端にはダイオード22のアノードとダイオード23のカソードが接続される。ダイオード22のカソードには平滑コンデンサ24の正極端子が接続され、ダイオード23のアノードには平滑コンデンサ24の負極端子が接続される。ダイオード22、ダイオード23、及び平滑コンデンサ24で交流電源3の交流電圧を整流して直流電圧を出力する第2の整流回路を構成する。平滑コンデンサ24としては電解コンデンサが好適である。また、後述するように、平滑コンデンサ24の電圧は室外機1の起動時に利用されるものであるため、平滑コンデンサ24の容量は主回路コンデンサ15よりも小容量でよい。
One end of another PTC thermistor 21 is connected to the AC power supply side terminal of the relay 7, and the anode of the diode 22 and the cathode of the diode 23 are connected to the other end of the PTC thermistor 21. The positive terminal of the smoothing capacitor 24 is connected to the cathode of the diode 22, and the negative terminal of the smoothing capacitor 24 is connected to the anode of the diode 23. A diode 22, a diode 23, and a smoothing capacitor 24 constitute a second rectifier circuit that rectifies the AC voltage of the AC power supply 3 and outputs a DC voltage. As the smoothing capacitor 24, an electrolytic capacitor is suitable. Further, as will be described later, since the voltage of the smoothing capacitor 24 is used when the outdoor unit 1 is started, the capacity of the smoothing capacitor 24 may be smaller than that of the main circuit capacitor 15.
DC/DCコンバータ25は平滑コンデンサ24に並列接続され、平滑コンデンサ24の端子間電圧を入力してマイコン26等の室外機1内の回路素子で使用する各種の直流電圧(VCC)を生成する。マイコン26は室外機1の全体制御を統括するマイコンであり、室外機1が起動し、運転を行うためにはマイコン26が動作していることが必要になる。
The DC / DC converter 25 is connected in parallel to the smoothing capacitor 24 and inputs a voltage between terminals of the smoothing capacitor 24 to generate various DC voltages (VCC) used in circuit elements in the outdoor unit 1 such as the microcomputer 26. The microcomputer 26 is a microcomputer that controls the overall control of the outdoor unit 1, and it is necessary for the microcomputer 26 to operate in order to start and operate the outdoor unit 1.
主回路コンデンサ15の端子間電圧は、ダイオード27とダイオード28を介してDC/DCコンバータ25にも入力される。DC/DCコンバータ25は主回路コンデンサ15の端子間電圧と平滑コンデンサ24の端子間電圧の両方の電圧に対応可能な入力電圧範囲を持つものを使用する。ダイオード27,28は平滑コンデンサ24から主回路コンデンサ15方向への直流電流を阻止する役割も有している。また、出力電圧検出部40は主回路コンデンサ15の端子間電圧を検出し、検出した電圧値をコンバータ出力電圧値としてマイコン26の入力ポート(IN-1)に出力する。
The inter-terminal voltage of the main circuit capacitor 15 is also input to the DC / DC converter 25 via the diode 27 and the diode 28. As the DC / DC converter 25, a DC / DC converter 25 having an input voltage range that can correspond to both the voltage between the terminals of the main circuit capacitor 15 and the voltage between the terminals of the smoothing capacitor 24 is used. The diodes 27 and 28 also have a role of blocking direct current from the smoothing capacitor 24 toward the main circuit capacitor 15. The output voltage detection unit 40 detects the voltage across the terminals of the main circuit capacitor 15, and outputs the detected voltage value to the input port (IN-1) of the microcomputer 26 as a converter output voltage value.
次に、過電圧保護回路41の構成を説明する。過電圧保護回路41は、平滑コンデンサ24の端子間電圧に基づいて過電圧状態を検出する過電圧検出回路41aと、平滑コンデンサ24の電荷を放電する放電回路41bとからなる。まず、過電圧検出回路41aの回路構成について説明する。
Next, the configuration of the overvoltage protection circuit 41 will be described. The overvoltage protection circuit 41 includes an overvoltage detection circuit 41 a that detects an overvoltage state based on the voltage across the smoothing capacitor 24, and a discharge circuit 41 b that discharges the electric charge of the smoothing capacitor 24. First, the circuit configuration of the overvoltage detection circuit 41a will be described.
抵抗29、30は平滑コンデンサ24の正極端子と接地(GND)間に直列接続される。これにより、抵抗29、30は平滑コンデンサ24の端子間電圧を分圧して検出電圧Vdetを生成する。過電圧状態検出用のスイッチング素子32(ここでは一例としてトランジスタとする。)は、ベースが抵抗29、30の相互接続点に接続され、エミッタと接地間には定電圧ダイオード31が接続される。ここで定電圧ダイオード31の基準電圧(降伏電圧)をVzとする。また、トランジスタであるスイッチング素子32のベース・エミッタ間電圧をVbeとする。そうすると、スイッチング素子32は、検出電圧Vdetが基準電圧Vzとエミッタ・ベース間電圧Vbeの和(Vz+Vbe)より大きくなるとオン状態になり、検出電圧Vdetが基準電圧Vzとエミッタ・ベース間電圧Vbeの和(Vz+Vbe)より小さくなるとオフ状態になる。
The resistors 29 and 30 are connected in series between the positive terminal of the smoothing capacitor 24 and the ground (GND). As a result, the resistors 29 and 30 divide the voltage between the terminals of the smoothing capacitor 24 to generate the detection voltage Vdet. The switching element 32 for detecting an overvoltage state (here, a transistor is used as an example) has a base connected to the interconnection point of the resistors 29 and 30, and a constant voltage diode 31 connected between the emitter and the ground. Here, the reference voltage (breakdown voltage) of the constant voltage diode 31 is Vz. The base-emitter voltage of the switching element 32, which is a transistor, is Vbe. Then, the switching element 32 is turned on when the detection voltage Vdet becomes larger than the sum (Vz + Vbe) of the reference voltage Vz and the emitter-base voltage Vbe, and the detection voltage Vdet is the sum of the reference voltage Vz and the emitter-base voltage Vbe. When it becomes smaller than (Vz + Vbe), it is turned off.
抵抗33、34は平滑コンデンサ24の正極端子とスイッチング素子32のコレクタ間に直列接続される。フォトカプラ35のフォトダイオードは抵抗34に並列接続される。抵抗33、34はフォトカプラ35のフォトダイオードに流れる電流を制限する。抵抗36の一端はDC/DCコンバータ25が生成する直流電源(VCC)に接続され、抵抗36の他端はフォトカプラ35のフォトトランジスタのコレクタに接続される。フォトカプラ35のフォトトランジスタのコレクタとエミッタ間にはコンデンサ37が接続され、フォトカプラ35のフォトトランジスタのエミッタは接地される。抵抗36はフォトカプラ35のフォトトランジスタに流れる電流を制限し、コンデンサ37はフォトカプラ35出力に重畳するノイズを除去する為のものである。そして、フォトカプラ35のフォトトランジスタのコレクタ端子がマイコン26へ接続される。
Resistors 33 and 34 are connected in series between the positive terminal of the smoothing capacitor 24 and the collector of the switching element 32. The photodiode of the photocoupler 35 is connected in parallel with the resistor 34. The resistors 33 and 34 limit the current flowing through the photodiode of the photocoupler 35. One end of the resistor 36 is connected to a direct current power supply (VCC) generated by the DC / DC converter 25, and the other end of the resistor 36 is connected to the collector of the phototransistor of the photocoupler 35. A capacitor 37 is connected between the collector and emitter of the phototransistor of the photocoupler 35, and the emitter of the phototransistor of the photocoupler 35 is grounded. The resistor 36 limits the current flowing through the phototransistor of the photocoupler 35, and the capacitor 37 is for removing noise superimposed on the output of the photocoupler 35. Then, the collector terminal of the phototransistor of the photocoupler 35 is connected to the microcomputer 26.
過電圧検出回路41aは以上のように構成されているので、平滑コンデンサ24が過電圧状態になると、スイッチング素子32がオン状態となり、フォトカプラ35が導通することで、フォトカプラ35から低電位(GND電位)がマイコン26の入力ポート(IN-2)へ出力される。一方、平滑コンデンサ24が過電圧状態でない時には、スイッチング素子32がオフ状態となり、フォトカプラ35が非導通状態になり、フォトカプラ35から高電位(VCC)がマイコン26へ出力される。このようにして、マイコン26は平滑コンデンサ24の過電圧状態を把握することができる。マイコン26は過電圧状態の把握に基づいてリレー7及びリレー17の開閉を制御する。リレー7,17の開閉制御手順については後述する。なお、ブレーカ4及びリレー7,17の開閉状態を表記するのに、開状態をオフ、閉状態をオンとも表記することにする。
Since the overvoltage detection circuit 41a is configured as described above, when the smoothing capacitor 24 is in an overvoltage state, the switching element 32 is turned on and the photocoupler 35 is turned on, whereby the photocoupler 35 is turned on to a low potential (GND potential). ) Is output to the input port (IN-2) of the microcomputer 26. On the other hand, when the smoothing capacitor 24 is not in an overvoltage state, the switching element 32 is turned off, the photocoupler 35 is turned off, and a high potential (VCC) is output from the photocoupler 35 to the microcomputer 26. In this way, the microcomputer 26 can grasp the overvoltage state of the smoothing capacitor 24. The microcomputer 26 controls the opening and closing of the relays 7 and 17 based on the grasp of the overvoltage state. The procedure for opening / closing the relays 7 and 17 will be described later. In addition, in order to describe the open / closed state of the breaker 4 and the relays 7 and 17, the open state will be expressed as OFF and the closed state will be expressed as ON.
次に、平滑コンデンサ24の電荷を放電させる放電回路41bの構成を説明する。放電用のスイッチング素子38(ここでは一例としてトランジスタとする。)のベースがスイッチング素子32のコレクタに接続され、スイッチング素子38のコレクタが接地されている。平滑コンデンサ24の正極端子とスイッチング素子38のエミッタ間には抵抗39が接続されている。
Next, the configuration of the discharge circuit 41b that discharges the electric charge of the smoothing capacitor 24 will be described. The base of the discharge switching element 38 (here, a transistor is taken as an example) is connected to the collector of the switching element 32, and the collector of the switching element 38 is grounded. A resistor 39 is connected between the positive terminal of the smoothing capacitor 24 and the emitter of the switching element 38.
放電回路41bは以上のように構成されているので、過電圧状態検出用のスイッチング素子32がオン状態(過電圧状態を検出時)になると、スイッチング素子38がオンし、平滑コンデンサ24の電荷が抵抗39経由で放電される。一方、過電圧状態でない時はスイッチング素子32がオフ状態であるので、スイッチング素子38がオフし、平滑コンデンサ24の電荷は放電されない。
Since the discharge circuit 41b is configured as described above, when the switching element 32 for detecting an overvoltage state is turned on (when an overvoltage state is detected), the switching element 38 is turned on, and the charge of the smoothing capacitor 24 is changed to the resistance 39. Discharged via. On the other hand, when not in an overvoltage state, since the switching element 32 is in an off state, the switching element 38 is turned off, and the charge of the smoothing capacitor 24 is not discharged.
次に、室外機1全体の動作状態と関連させて、本実施の形態の電力変換装置の動作を説明する。図2に室外機1が停止している状態から起動し、通常モード、及び無効電力削減モードに移行する場合の動作タイミング図を示す。なお、各モードの詳細は後述する。
Next, the operation of the power conversion device of the present embodiment will be described in relation to the operation state of the outdoor unit 1 as a whole. FIG. 2 shows an operation timing chart when the outdoor unit 1 is started from a stopped state and shifts to the normal mode and the reactive power reduction mode. Details of each mode will be described later.
[1]停止
最初に室外機1が停止状態にある時(図2:停止)には、ブレーカ4がオフ状態であるので交流電源3の交流電力は室外機1及び室内機2に給電されていない。また、リレー17,リレー7もともにオフ状態であり、交流電源3から主回路コンデンサ15への充電経路が遮断されている。 [1] Stop When theoutdoor unit 1 is initially stopped (FIG. 2: stop), the AC power from the AC power source 3 is supplied to the outdoor unit 1 and the indoor unit 2 because the breaker 4 is in the OFF state. Absent. Further, both the relay 17 and the relay 7 are in an off state, and the charging path from the AC power source 3 to the main circuit capacitor 15 is interrupted.
最初に室外機1が停止状態にある時(図2:停止)には、ブレーカ4がオフ状態であるので交流電源3の交流電力は室外機1及び室内機2に給電されていない。また、リレー17,リレー7もともにオフ状態であり、交流電源3から主回路コンデンサ15への充電経路が遮断されている。 [1] Stop When the
[2]起動(1)
次に、ブレーカ4をオフからオンに切り替えることで、室外機1が起動する(図2:起動(1))。ブレーカ4の操作は空気調和機のユーザが手動で行う。この時、リレー7とリレー17はオフ状態のままである。これにより、交流電源3の交流電力により平滑コンデンサ24を充電する電流経路が形成される。図3は交流電源3の電圧位相が正の半波の時の電流経路である。ここで、交流電源3のブレーカ4側の電位がブレーカ4に接続していない側の電位より高い時に、交流電源3の電圧位相を「正」とし、ブレーカ4側の電位がブレーカ4に接続していない側の電位より低い時に、交流電源3の電圧位相を「負」と定義する。交流電源3の電圧位相が正の半波の時は、交流電源3→ノイズフィルタ5→PTCサーミスタ21→ダイオード22→平滑コンデンサ24→ダイオード28→全波整流回路9→ノイズフィルタ5→交流電源3の経路で電流が流れ、平滑コンデンサ24が充電される。ここで、PTCサーミスタ21は室外機1の起動時に交流電源3から平滑コンデンサ24への突入電流を抑制するために設けたものである。 [2] Startup (1)
Next, theoutdoor unit 1 is activated by switching the breaker 4 from off to on (FIG. 2: activation (1)). The breaker 4 is manually operated by the user of the air conditioner. At this time, the relay 7 and the relay 17 remain off. As a result, a current path for charging the smoothing capacitor 24 with the AC power of the AC power supply 3 is formed. FIG. 3 shows a current path when the voltage phase of the AC power supply 3 is a positive half wave. Here, when the potential on the breaker 4 side of the AC power supply 3 is higher than the potential on the side not connected to the breaker 4, the voltage phase of the AC power supply 3 is set to “positive”, and the potential on the breaker 4 side is connected to the breaker 4. The voltage phase of the AC power supply 3 is defined as “negative” when the potential is lower than the non-side potential. When the voltage phase of the AC power supply 3 is a positive half wave, the AC power supply 3 → the noise filter 5 → the PTC thermistor 21 → the diode 22 → the smoothing capacitor 24 → the diode 28 → the full wave rectifier circuit 9 → the noise filter 5 → the AC power supply 3 A current flows through the path, and the smoothing capacitor 24 is charged. Here, the PTC thermistor 21 is provided to suppress an inrush current from the AC power supply 3 to the smoothing capacitor 24 when the outdoor unit 1 is started.
次に、ブレーカ4をオフからオンに切り替えることで、室外機1が起動する(図2:起動(1))。ブレーカ4の操作は空気調和機のユーザが手動で行う。この時、リレー7とリレー17はオフ状態のままである。これにより、交流電源3の交流電力により平滑コンデンサ24を充電する電流経路が形成される。図3は交流電源3の電圧位相が正の半波の時の電流経路である。ここで、交流電源3のブレーカ4側の電位がブレーカ4に接続していない側の電位より高い時に、交流電源3の電圧位相を「正」とし、ブレーカ4側の電位がブレーカ4に接続していない側の電位より低い時に、交流電源3の電圧位相を「負」と定義する。交流電源3の電圧位相が正の半波の時は、交流電源3→ノイズフィルタ5→PTCサーミスタ21→ダイオード22→平滑コンデンサ24→ダイオード28→全波整流回路9→ノイズフィルタ5→交流電源3の経路で電流が流れ、平滑コンデンサ24が充電される。ここで、PTCサーミスタ21は室外機1の起動時に交流電源3から平滑コンデンサ24への突入電流を抑制するために設けたものである。 [2] Startup (1)
Next, the
一方、交流電源3の電圧位相が負の半波の時には、図4に示す電流経路が形成される。これにより、交流電源3→ノイズフィルタ5→全波整流回路9→コンバータ主回路10→ダイオード27→平滑コンデンサ24→ダイオード23→PTCサーミスタ21→ノイズフィルタ5→交流電源3の経路で電流が流れ、平滑コンデンサ24が充電される。
On the other hand, when the voltage phase of the AC power supply 3 is a negative half wave, the current path shown in FIG. 4 is formed. As a result, current flows through the path of the AC power source 3 → the noise filter 5 → the full wave rectifier circuit 9 → the converter main circuit 10 → the diode 27 → the smoothing capacitor 24 → the diode 23 → the PTC thermistor 21 → the noise filter 5 → the AC power source 3. The smoothing capacitor 24 is charged.
このようにして、平滑コンデンサ24の端子間には交流電源3を整流した直流電圧が発生する。この直流電圧はDC/DCコンバータ25に入力され、DC/DCコンバータ25がマイコン26用の直流電源を生成することで、マイコン26が起動する。マイコン26は図示しない記憶素子に予め記憶されたプログラムを実行することで、室外機1全体を管理・制御することが可能になる。
In this way, a DC voltage obtained by rectifying the AC power supply 3 is generated between the terminals of the smoothing capacitor 24. The DC voltage is input to the DC / DC converter 25, and the DC / DC converter 25 generates a DC power source for the microcomputer 26, whereby the microcomputer 26 is activated. The microcomputer 26 can manage and control the entire outdoor unit 1 by executing a program stored in advance in a storage element (not shown).
[3]起動(2)
次にマイコン26の制御により、リレー17をオン状態に切り替える(図2:起動(2))。これにより、交流電源3の電圧位相が正の半波の時に、交流電源3→ノイズフィルタ5→PTCサーミスタ16→リレー17→ダイオード18→主回路コンデンサ15→全波整流回路9→ノイズフィルタ5→交流電源3の経路で電流が流れ、主回路コンデンサ15が充電される。こうして、主回路コンデンサ15の端子間には交流電源3を半波整流した直流電圧が発生する。 [3] Startup (2)
Next, therelay 17 is switched to the ON state under the control of the microcomputer 26 (FIG. 2: activation (2)). Thus, when the voltage phase of the AC power supply 3 is a positive half wave, the AC power supply 3 → the noise filter 5 → the PTC thermistor 16 → the relay 17 → the diode 18 → the main circuit capacitor 15 → the full wave rectifier circuit 9 → the noise filter 5 → A current flows through the path of the AC power supply 3, and the main circuit capacitor 15 is charged. Thus, a DC voltage generated by half-wave rectification of the AC power supply 3 is generated between the terminals of the main circuit capacitor 15.
次にマイコン26の制御により、リレー17をオン状態に切り替える(図2:起動(2))。これにより、交流電源3の電圧位相が正の半波の時に、交流電源3→ノイズフィルタ5→PTCサーミスタ16→リレー17→ダイオード18→主回路コンデンサ15→全波整流回路9→ノイズフィルタ5→交流電源3の経路で電流が流れ、主回路コンデンサ15が充電される。こうして、主回路コンデンサ15の端子間には交流電源3を半波整流した直流電圧が発生する。 [3] Startup (2)
Next, the
[4]起動(3)
次にマイコン26は出力電圧検出部40の検出値に基づいて、コンバータ出力電圧(主回路コンデンサ15の端子間電圧)が所定の電圧閾値以上になったことを確認後、リレー7をオン状態にする(図2:起動(3))。これにより、全波整流回路9及びコンバータ主回路10を経由した主回路コンデンサ15への充電経路が形成される。 [4] Startup (3)
Next, themicrocomputer 26 confirms that the converter output voltage (the voltage across the terminals of the main circuit capacitor 15) is equal to or higher than a predetermined voltage threshold based on the detection value of the output voltage detector 40, and then turns the relay 7 on (FIG. 2: Activation (3)). Thereby, a charging path to the main circuit capacitor 15 via the full-wave rectifier circuit 9 and the converter main circuit 10 is formed.
次にマイコン26は出力電圧検出部40の検出値に基づいて、コンバータ出力電圧(主回路コンデンサ15の端子間電圧)が所定の電圧閾値以上になったことを確認後、リレー7をオン状態にする(図2:起動(3))。これにより、全波整流回路9及びコンバータ主回路10を経由した主回路コンデンサ15への充電経路が形成される。 [4] Startup (3)
Next, the
また、リレー7をオン状態に切り替える時点では、主回路コンデンサ15はある程度充電された状態にあるので、リレー7をオン状態に切り替えた際に全波整流回路9及びコンバータ主回路10に過大な突入電流が流れることを防止できる。前述したコンバータ出力電圧の電圧閾値はこの突入電流が抑制できる効果を考慮して設定すればよい。
Further, since the main circuit capacitor 15 is in a state of being charged to some extent at the time when the relay 7 is switched on, excessive rushing into the full-wave rectifier circuit 9 and the converter main circuit 10 occurs when the relay 7 is switched on. Current can be prevented from flowing. The voltage threshold value of the converter output voltage described above may be set in consideration of the effect that this inrush current can be suppressed.
[5]通常モード
次にマイコン26はリレー7をオン状態に切り替え後、所定の時間経過後にリレー17をオフ状態にする(図2:通常モード))。これにより、ダイオード18を経由する主回路コンデンサ15へのバイパス充電経路が遮断され、主回路コンデンサ15はコンバータ主回路10を経由した充電経路のみで充電される。また、通常モード時にはコンバータ主回路10に昇圧動作(スイッチング素子12a,12bのオン・オフ制御)をさせることにより、全波整流回路9の出力電圧を昇圧した直流電圧が主回路コンデンサ15の端子間に生成される。 [5] Normal Mode Next, themicrocomputer 26 switches the relay 7 to the ON state, and then turns the relay 17 to the OFF state after a predetermined time has elapsed (FIG. 2: normal mode). As a result, the bypass charging path to the main circuit capacitor 15 via the diode 18 is blocked, and the main circuit capacitor 15 is charged only through the charging path via the converter main circuit 10. In the normal mode, the converter main circuit 10 performs a boost operation (on / off control of the switching elements 12a and 12b), so that the DC voltage obtained by boosting the output voltage of the full-wave rectifier circuit 9 is between the terminals of the main circuit capacitor 15. Is generated.
次にマイコン26はリレー7をオン状態に切り替え後、所定の時間経過後にリレー17をオフ状態にする(図2:通常モード))。これにより、ダイオード18を経由する主回路コンデンサ15へのバイパス充電経路が遮断され、主回路コンデンサ15はコンバータ主回路10を経由した充電経路のみで充電される。また、通常モード時にはコンバータ主回路10に昇圧動作(スイッチング素子12a,12bのオン・オフ制御)をさせることにより、全波整流回路9の出力電圧を昇圧した直流電圧が主回路コンデンサ15の端子間に生成される。 [5] Normal Mode Next, the
主回路コンデンサ15の端子間電圧であるコンバータ出力電圧はインバータ主回路19に供給され、インバータ主回路19はコンバータ出力電圧を電源としてモータ20を回転駆動することで、空気調和機の通常の運転動作が実行される。
The converter output voltage, which is the voltage between the terminals of the main circuit capacitor 15, is supplied to the inverter main circuit 19, and the inverter main circuit 19 rotates and drives the motor 20 using the converter output voltage as a power source. Is executed.
以下では、室外機1が通常モードで動作している時の過電圧保護回路41の動作について説明する。まず平滑コンデンサ24が過電圧状態になっていない場合について説明する。前述したように、平滑コンデンサ24の端子間電圧を分圧した検出電圧Vdetが定電圧ダイオード31の基準電圧Vzとスイッチング素子32のエミッタ・ベース間電圧Vbeの和(Vz+Vbe)以下であればスイッチング素子32はオフ状態であり、マイコン26へ過電圧の検出状態を伝達するフォトカプラ35は非導通となる。そしてマイコン26の入力ポートには高電位(VCC)が入力されるので、マイコン26は平滑コンデンサ24の端子間電圧が「通常状態(過電圧状態ではない)」であると認識する。
Hereinafter, the operation of the overvoltage protection circuit 41 when the outdoor unit 1 is operating in the normal mode will be described. First, the case where the smoothing capacitor 24 is not in an overvoltage state will be described. As described above, if the detection voltage Vdet obtained by dividing the voltage between the terminals of the smoothing capacitor 24 is equal to or less than the sum (Vz + Vbe) of the reference voltage Vz of the constant voltage diode 31 and the emitter-base voltage Vbe of the switching element 32, the switching element. Reference numeral 32 denotes an off state, and the photocoupler 35 that transmits the overvoltage detection state to the microcomputer 26 becomes non-conductive. Since a high potential (VCC) is input to the input port of the microcomputer 26, the microcomputer 26 recognizes that the voltage between the terminals of the smoothing capacitor 24 is “normal state (not an overvoltage state)”.
ここで平滑コンデンサ24の端子間電圧をVc、抵抗29、30の抵抗値をそれぞれR29,R30とするとマイコン26が平滑コンデンサ24の端子間電圧が「通常状態(過電圧状態ではない)」であると判定する条件は、(式1)、(式2)から(式3)となる。
(式1)Vdet≦Vz+Vbe
(式2)Vdet=Vc・R30/(R29+R30)
(式3)Vc≦(R29/R30+1)・(Vz+Vbe) Here, if the voltage between the terminals of the smoothingcapacitor 24 is Vc and the resistance values of the resistors 29 and 30 are R29 and R30, respectively, the microcomputer 26 indicates that the voltage between the terminals of the smoothing capacitor 24 is “normal state (not overvoltage state)”. The conditions for determination are (Expression 1), (Expression 2) to (Expression 3).
(Formula 1) Vdet ≦ Vz + Vbe
(Formula 2) Vdet = Vc · R30 / (R29 + R30)
(Formula 3) Vc ≦ (R29 / R30 + 1) · (Vz + Vbe)
(式1)Vdet≦Vz+Vbe
(式2)Vdet=Vc・R30/(R29+R30)
(式3)Vc≦(R29/R30+1)・(Vz+Vbe) Here, if the voltage between the terminals of the smoothing
(Formula 1) Vdet ≦ Vz + Vbe
(Formula 2) Vdet = Vc · R30 / (R29 + R30)
(Formula 3) Vc ≦ (R29 / R30 + 1) · (Vz + Vbe)
従って、マイコン26は(式4)で定義される過電圧検出の判定電圧閾値Vth1に基づいて過電圧検出していることになる。
(式4)Vth1=(R29/R30+1)・(Vz+Vbe)
従って、判定電圧閾値Vth1は、抵抗29、30の抵抗値で決まる抵抗比R29/R30、及び定電圧ダイオード31の基準電圧Vzとスイッチング素子32のエミッタ・ベース間電圧Vbeの和(Vz+Vbe)に基づいて決まる。ここで判定電圧閾値Vth1は、平滑コンデンサ24を含む使用している電子部品の耐圧定格よりも判定電圧閾値Vth1が小さくなるように設定すればよい。 Therefore, themicrocomputer 26 detects overvoltage based on the determination voltage threshold Vth1 of overvoltage detection defined by (Equation 4).
(Formula 4) Vth1 = (R29 / R30 + 1). (Vz + Vbe)
Therefore, the determination voltage threshold Vth1 is based on the resistance ratio R29 / R30 determined by the resistance values of the resistors 29 and 30, and the sum (Vz + Vbe) of the reference voltage Vz of the constant voltage diode 31 and the emitter-base voltage Vbe of the switching element 32. Determined. Here, the determination voltage threshold value Vth1 may be set so that the determination voltage threshold value Vth1 is smaller than the withstand voltage rating of the electronic components in use including the smoothing capacitor 24.
(式4)Vth1=(R29/R30+1)・(Vz+Vbe)
従って、判定電圧閾値Vth1は、抵抗29、30の抵抗値で決まる抵抗比R29/R30、及び定電圧ダイオード31の基準電圧Vzとスイッチング素子32のエミッタ・ベース間電圧Vbeの和(Vz+Vbe)に基づいて決まる。ここで判定電圧閾値Vth1は、平滑コンデンサ24を含む使用している電子部品の耐圧定格よりも判定電圧閾値Vth1が小さくなるように設定すればよい。 Therefore, the
(Formula 4) Vth1 = (R29 / R30 + 1). (Vz + Vbe)
Therefore, the determination voltage threshold Vth1 is based on the resistance ratio R29 / R30 determined by the resistance values of the
通常状態(過電圧状態ではない)時は、スイッチング素子32はオフ状態を維持しているので、放電回路のスイッチング素子38はオフ状態となり平滑コンデンサ24に蓄積されている電荷が放電されることはない。
In a normal state (not an overvoltage state), since the switching element 32 is maintained in an off state, the switching element 38 of the discharge circuit is in an off state, and the charge accumulated in the smoothing capacitor 24 is not discharged. .
このように、平滑コンデンサ24の端子間電圧Vcが過電圧検出の判定電圧閾値Vth1以下の時は、マイコン26は平滑コンデンサ24の端子間電圧が「通常状態(過電圧状態ではない)」であると認識するとともに、放電回路は動作せず、平滑コンデンサ24の電荷は放電されない。また、マイコン26はリレー7及びリレー17のオン・オフ状態を変更することはしない。
Thus, when the inter-terminal voltage Vc of the smoothing capacitor 24 is equal to or lower than the determination voltage threshold Vth1 for overvoltage detection, the microcomputer 26 recognizes that the inter-terminal voltage of the smoothing capacitor 24 is “normal state (not overvoltage state)”. At the same time, the discharge circuit does not operate and the charge of the smoothing capacitor 24 is not discharged. Further, the microcomputer 26 does not change the on / off states of the relay 7 and the relay 17.
室外機1が通常モードで動作している時には、マイコン26は出力電圧検出部40が検出したコンバータ出力電圧値に基づいて過電圧状態を検出している。この時、コンバータ出力電圧値に基づく過電圧検出の判定閾値Vth2を前述した過電圧検出回路41aの信号に基づく過電圧検出の判定電圧閾値Vth1より小さく設定すれば(即ちVth2<Vth1)、マイコン26は過電圧検出回路で過電圧を検出する前に過電圧に対する保護動作を実行できる。従って、通常モードで動作時には過電圧検出回路41aが過電圧状態を検出するケースは実運用上少ないと考えられる為、そのようなケースでの回路動作の説明は割愛する。
When the outdoor unit 1 is operating in the normal mode, the microcomputer 26 detects an overvoltage state based on the converter output voltage value detected by the output voltage detection unit 40. At this time, if the determination threshold value Vth2 for overvoltage detection based on the converter output voltage value is set to be smaller than the determination voltage threshold value Vth1 for overvoltage detection based on the signal from the overvoltage detection circuit 41a (that is, Vth2 <Vth1), the microcomputer 26 detects overvoltage. An overvoltage protection operation can be performed before the circuit detects the overvoltage. Accordingly, it is considered that there are few cases in which the overvoltage detection circuit 41a detects an overvoltage state when operating in the normal mode in practice, and therefore description of the circuit operation in such a case is omitted.
[5]無効電力削減モード
次に、無効電力削減モードでの過電圧検出回路及び放電回路の動作について説明する。ここで、無効電力削減モードとは、通常モード時のモータ20の運転が終了し、コンバータ主回路10及びインバータ主回路19への電力供給が不要になった時に、コンデンサ8を流れる無効電流を減らすことで無効電力を削減させる動作モードである。 [5] Reactive power reduction mode Next, operations of the overvoltage detection circuit and the discharge circuit in the reactive power reduction mode will be described. Here, the reactive power reduction mode is to reduce the reactive current flowing through thecapacitor 8 when the operation of the motor 20 in the normal mode is finished and the power supply to the converter main circuit 10 and the inverter main circuit 19 becomes unnecessary. This is an operation mode for reducing reactive power.
次に、無効電力削減モードでの過電圧検出回路及び放電回路の動作について説明する。ここで、無効電力削減モードとは、通常モード時のモータ20の運転が終了し、コンバータ主回路10及びインバータ主回路19への電力供給が不要になった時に、コンデンサ8を流れる無効電流を減らすことで無効電力を削減させる動作モードである。 [5] Reactive power reduction mode Next, operations of the overvoltage detection circuit and the discharge circuit in the reactive power reduction mode will be described. Here, the reactive power reduction mode is to reduce the reactive current flowing through the
無効電力削減モードへの移行は、通常モード時のモータ20の運転が終了した後、あらかじめ設定した所定時間経過後にマイコン26の制御により、リレー7をオフにすることで行われる。なおリレー17はオフ状態を維持する(図2:無効電力削減モード)。
The transition to the reactive power reduction mode is performed by turning off the relay 7 under the control of the microcomputer 26 after a predetermined time has elapsed after the operation of the motor 20 in the normal mode is completed. In addition, the relay 17 maintains an OFF state (FIG. 2: Reactive power reduction mode).
無効電力削減モードへの移行でリレー7がオン状態からオフ状態に切り替わる際に、コンデンサ8に電荷が残留していた場合、この残留電荷によるコンデンサ8の端子間電圧の極性と交流電源3の電圧極性の関係に応じて、平滑コンデンサ24の端子間に過電圧状態を発生させる電流経路が形成される。
If the charge remains in the capacitor 8 when the relay 7 is switched from the on state to the off state in the transition to the reactive power reduction mode, the polarity of the voltage between the terminals of the capacitor 8 and the voltage of the AC power source 3 due to the residual charge A current path for generating an overvoltage state is formed between the terminals of the smoothing capacitor 24 in accordance with the polarity relationship.
ここでは説明しやすいように、コンデンサ8の2つの端子のうち、ブレーカ4と接続されている端子をコンデンサ8の第1端子、他方の端子をコンデンサ8の第2端子と定義する。そして、コンデンサ8の第1端子がコンデンサ8の第2端子より高電位の時、コンデンサ8の端子間電圧が正極性とし、コンデンサ8の第1端子がコンデンサ8の第2端子より低電位の時、コンデンサ8の端子間電圧が負極性と定義する。
Here, for easy explanation, of the two terminals of the capacitor 8, the terminal connected to the breaker 4 is defined as the first terminal of the capacitor 8 and the other terminal is defined as the second terminal of the capacitor 8. When the first terminal of the capacitor 8 is at a higher potential than the second terminal of the capacitor 8, the voltage between the terminals of the capacitor 8 is positive, and when the first terminal of the capacitor 8 is at a lower potential than the second terminal of the capacitor 8. The voltage between terminals of the capacitor 8 is defined as negative polarity.
平滑コンデンサ24の端子間に過電圧状態が発生する1つ目の電流経路は、コンデンサ8の第1端子に正電荷が残留している状態で、かつ交流電源3の電圧位相が負である時に無効電力削減モードに移行した場合に形成される。具体的には図5に示すように、交流電源3→ノイズフィルタ5→コンデンサ8→全波整流回路9→コンバータ主回路10→ダイオード27→平滑コンデンサ24→ダイオード23→PTCサーミスタ21→ノイズフィルタ5→交流電源3の経路で電流が流れる。この為、コンデンサ8の端子間電圧と交流電源3の電源電圧を加算した電圧が平滑コンデンサ24の端子間に印加されることで、平滑コンデンサ24の端子間に過電圧状態が発生する。なお、図5ではコンデンサ8の残留電荷の極性を示すプラス(+)・マイナス(-)記号を付記している。
The first current path in which an overvoltage state occurs between the terminals of the smoothing capacitor 24 is invalid when a positive charge remains at the first terminal of the capacitor 8 and the voltage phase of the AC power supply 3 is negative. It is formed when shifting to the power reduction mode. Specifically, as shown in FIG. 5, AC power supply 3 → noise filter 5 → capacitor 8 → full wave rectifier circuit 9 → converter main circuit 10 → diode 27 → smoothing capacitor 24 → diode 23 → PTC thermistor 21 → noise filter 5 → Current flows through the path of the AC power source 3. For this reason, an overvoltage state is generated between the terminals of the smoothing capacitor 24 by applying a voltage obtained by adding the voltage between the terminals of the capacitor 8 and the power supply voltage of the AC power supply 3 between the terminals of the smoothing capacitor 24. In FIG. 5, plus (+) / minus (−) symbols indicating the polarity of the residual charge of the capacitor 8 are added.
平滑コンデンサ24の端子間に過電圧状態が発生する2つ目の電流経路は、コンデンサ8の第1端子に負電荷が残留している状態で、かつ交流電源3の電圧位相が正である時に無効電力削減モードに移行した場合に形成される。具体的には図6に示すように、交流電源3→ノイズフィルタ5→PTCサーミスタ21→ダイオード22→平滑コンデンサ24→ダイオード28→全波整流回路9→コンデンサ8→ノイズフィルタ5→交流電源3の経路で電流が流れる。この為、コンデンサ8の端子間電圧と交流電源3の電圧を加算した電圧が平滑コンデンサ24の端子間に印加されることで、平滑コンデンサ24の端子間に過電圧状態が発生する。なお、図6ではコンデンサ8の残留電荷の極性を示すプラス(+)・マイナス(-)記号を付記している。
The second current path in which an overvoltage state occurs between the terminals of the smoothing capacitor 24 is invalid when negative charge remains in the first terminal of the capacitor 8 and the voltage phase of the AC power supply 3 is positive. It is formed when shifting to the power reduction mode. Specifically, as shown in FIG. 6, the AC power source 3 → the noise filter 5 → the PTC thermistor 21 → the diode 22 → the smoothing capacitor 24 → the diode 28 → the full wave rectifier circuit 9 → the capacitor 8 → the noise filter 5 → the AC power source 3. Current flows through the path. For this reason, the voltage obtained by adding the voltage between the terminals of the capacitor 8 and the voltage of the AC power supply 3 is applied between the terminals of the smoothing capacitor 24, thereby generating an overvoltage state between the terminals of the smoothing capacitor 24. In FIG. 6, plus (+) / minus (−) symbols indicating the polarity of the residual charge of the capacitor 8 are added.
この為、電力変換装置の動作時に想定されるコンデンサ8の残留電荷量の最大値及び交流電源3の電圧変動範囲を予め規定することで平滑コンデンサ24に必要な耐圧を算定し、平滑コンデンサ24としてこの耐圧特性を満たす部品を選定することができればよい。しかしながら、実際に選定可能なコンデンサ部品の耐圧特性には限度があること、及び外部の電源供給系統の異常等で規定した範囲を逸脱する交流電源3の大きな電圧変動が発生しうることから、あらゆる状況に対処できるようなコンデンサ部品を予め選定することは難しい。
For this reason, the withstand voltage required for the smoothing capacitor 24 is calculated by predefining the maximum residual charge amount of the capacitor 8 and the voltage fluctuation range of the AC power supply 3 that are assumed when the power converter is operated. It is only necessary to select a component that satisfies this pressure resistance characteristic. However, since the withstand voltage characteristics of actually selectable capacitor parts are limited and large voltage fluctuations of the AC power supply 3 deviating from the range specified by the abnormality of the external power supply system or the like can occur. It is difficult to pre-select capacitor components that can cope with the situation.
次に、平滑コンデンサ24の端子間に過電圧状態が発生した場合の過電圧保護回路41の動作を説明する。図7は過電圧保護回路41の各部の動作波形を示す図である。図7において、(a)は平滑コンデンサ24の端子間電圧を示し、(b)及び(c)はそれぞれスイッチング素子32,38のオン・オフ状態を示す。(d)はマイコン26の入力ポート(IN-2)の入力電圧であり、これはフォトカプラ35のコレクタ電圧でもある。(e)及び(f)はそれぞれリレー17,7のオン・オフ状態を示す。
Next, the operation of the overvoltage protection circuit 41 when an overvoltage state occurs between the terminals of the smoothing capacitor 24 will be described. FIG. 7 is a diagram showing operation waveforms of each part of the overvoltage protection circuit 41. 7A shows the voltage between the terminals of the smoothing capacitor 24, and FIGS. 7B and 7C show the on / off states of the switching elements 32 and 38, respectively. (D) is the input voltage of the input port (IN-2) of the microcomputer 26, which is also the collector voltage of the photocoupler 35. (E) and (f) show ON / OFF states of the relays 17 and 7, respectively.
前述したように通常モードで動作中にはリレー17はオフ状態で、リレー7はオン状態にある。ここで、リレー7をオフ状態に切り換える(時間T1)ことにより無効電力削減モードに移行すると、図5もしくは図6に示した電流経路で平滑コンデンサ24に過電圧が印加され、平滑コンデンサ24の端子間電圧が上昇する。そして、平滑コンデンサ24の端子間電圧が、前述した過電圧検出の判定電圧閾値Vth1より大きくなると(時間T2)、スイッチング素子32がターンオンする。なお、ターンオンとはスイッチング素子がオフ状態からオン状態に移行することを意味する。
As described above, when operating in the normal mode, the relay 17 is in the off state and the relay 7 is in the on state. When switching to the reactive power reduction mode by switching the relay 7 to the OFF state (time T1), an overvoltage is applied to the smoothing capacitor 24 through the current path shown in FIG. The voltage rises. When the voltage between the terminals of the smoothing capacitor 24 becomes larger than the above-described determination voltage threshold value Vth1 for overvoltage detection (time T2), the switching element 32 is turned on. The turn-on means that the switching element shifts from the off state to the on state.
スイッチング素子32がオン状態になった後、引き続いて放電用のスイッチング素子38がターンオンする(時間T3)とともに、フォトカプラ35もターンオンする。スイッチング素子38がオン状態になることで、平滑コンデンサ24から抵抗39を経由して放電電流が流れ、平滑コンデンサ24の端子間電圧は低下していく。また、フォトカプラ35がオン状態になることで、マイコン26の入力ポート(IN-2)には低電位(GND電位)が入力され、マイコン26は平滑コンデンサ24の端子間電圧が過電圧状態であることを認識する。
After the switching element 32 is turned on, the discharge switching element 38 is subsequently turned on (time T3), and the photocoupler 35 is also turned on. When the switching element 38 is turned on, a discharge current flows from the smoothing capacitor 24 via the resistor 39, and the voltage between the terminals of the smoothing capacitor 24 decreases. In addition, when the photocoupler 35 is turned on, a low potential (GND potential) is input to the input port (IN-2) of the microcomputer 26, and the microcomputer 26 has an overvoltage state between the terminals of the smoothing capacitor 24. Recognize that.
このようにして、平滑コンデンサ24の端子間電圧は部品の耐圧レベルに到達する前に低下していくので、過電圧で部品故障になることを防止することができる。平滑コンデンサ24の端子間電圧が、過電圧検出の判定電圧閾値Vth1より小さくなると(時間T4)、スイッチング素子32がターンオフする。なお、ターンオフとはスイッチング素子がオン状態からオフ状態に移行することを意味する。
In this way, the voltage between the terminals of the smoothing capacitor 24 decreases before reaching the breakdown voltage level of the component, so that it is possible to prevent a component failure due to overvoltage. When the inter-terminal voltage of the smoothing capacitor 24 becomes smaller than the determination voltage threshold Vth1 for overvoltage detection (time T4), the switching element 32 is turned off. Note that the turn-off means that the switching element shifts from the on state to the off state.
スイッチング素子32がオフ状態になった後、引き続いて放電用のスイッチング素子38がターンオフする(時間T5)とともに、フォトカプラ35もターンオフする。スイッチング素子38がオフ状態になることで、平滑コンデンサ24から抵抗39を経由して流れていた放電電流の流れが停止し、平滑コンデンサ24の端子間電圧の低下も停止する。この時、電圧低下が停止した時点の平滑コンデンサ24の端子間電圧値は、スイッチング素子32及びスイッチング素子38のターンオフの時間遅延幅、及び抵抗39の抵抗値に依存する。なお、図7では説明をしやすくするために、スイッチング素子32及びスイッチング素子38のターンオン及びターンオフの時間遅延を誇張して示している。また、フォトカプラ35がオフ状態になることで、マイコン26の入力ポート(IN-2)には高電位(VCC電位)が入力され、マイコン26は平滑コンデンサ24の端子間が過電圧状態でなくなったことを認識する。
After the switching element 32 is turned off, the discharge switching element 38 is subsequently turned off (time T5), and the photocoupler 35 is also turned off. When the switching element 38 is turned off, the flow of the discharge current flowing from the smoothing capacitor 24 via the resistor 39 is stopped, and the decrease in the voltage between the terminals of the smoothing capacitor 24 is also stopped. At this time, the voltage value between the terminals of the smoothing capacitor 24 at the time when the voltage drop stops depends on the time delay width of turn-off of the switching element 32 and the switching element 38 and the resistance value of the resistor 39. In FIG. 7, the time delays of turning on and turning off the switching element 32 and the switching element 38 are exaggerated for easy explanation. Further, since the photocoupler 35 is turned off, a high potential (VCC potential) is input to the input port (IN-2) of the microcomputer 26, and the microcomputer 26 is no longer in an overvoltage state between the terminals of the smoothing capacitor 24. Recognize that.
図8は、図7におけるマイコン26の入力ポート(IN-2)の入力電圧が低電位(GND電位)になった部分を拡大して示したものである。図8において、(d)及び(f)は図7に示したものと同じ信号波形であり、(g)は入力ポート(IN-2)の入力電圧をマイコン26でサンプリングするサンプリングタイミングを示したものである。マイコン26は周期Tsで入力ポート(IN-2)の入力電圧をサンプリングする。ここで、周期Tsの値は図示しない記憶媒体にマイコン26が実行する処理プログラムの一部として予め設定しておけばよい。
FIG. 8 is an enlarged view of a portion where the input voltage of the input port (IN-2) of the microcomputer 26 in FIG. 7 becomes a low potential (GND potential). 8, (d) and (f) are the same signal waveforms as those shown in FIG. 7, and (g) shows the sampling timing at which the microcomputer 26 samples the input voltage of the input port (IN-2). Is. The microcomputer 26 samples the input voltage of the input port (IN-2) at the cycle Ts. Here, the value of the cycle Ts may be set in advance as a part of a processing program executed by the microcomputer 26 in a storage medium (not shown).
マイコン26はこのサンプリングした電圧値に基づいて、過電圧状態検出の有無を判断する。具体的には、図9に示すフロチャートに従って判断する。最初の処理(ステップS1)として、カウント値nをクリアする(n=0)。ここでカウント値nは、サンプリングした入力電圧が低電位であった回数をカウントするためのカウンタとして使用する。また、マイコン26はこの初期状態時には平滑コンデンサ24の端子間電圧が「正常状態」であるとみなす。ここで、「正常状態」とは後述する「過電圧状態」に至っていないことを意味する。
The microcomputer 26 determines whether or not an overvoltage state is detected based on the sampled voltage value. Specifically, the determination is made according to the flowchart shown in FIG. As the first process (step S1), the count value n is cleared (n = 0). Here, the count value n is used as a counter for counting the number of times the sampled input voltage is at a low potential. Further, in this initial state, the microcomputer 26 considers that the voltage between the terminals of the smoothing capacitor 24 is “normal state”. Here, the “normal state” means that the “overvoltage state” described later has not been reached.
次にマイコン26の入力ポート(IN-2)の入力電圧をサンプリングする(ステップS2)。サンプリングは周期Ts毎に行われる。以下の処理は1回のサンプリング値取得に対応して行う処理である。次に、サンプリングした電圧が低電位(GND電位)であるか否か判定する(ステップS3)。ここでサンプリングした電圧が低電位か否かは予め決めた閾値電圧により判断すればよく、低電位でない場合は高電位(VCC電位)であるとみなされる。サンプリングした電圧が高電位である場合には、カウンタnをクリアし(n=0)、マイコン26は電圧状態が「正常状態」であると判断する(ステップS4)。一方、サンプリングした電圧が低電位である場合にはカウンタnをカウントアップする(n→n+1)(ステップS5)。
Next, the input voltage at the input port (IN-2) of the microcomputer 26 is sampled (step S2). Sampling is performed every period Ts. The following processing is processing performed corresponding to one sampling value acquisition. Next, it is determined whether or not the sampled voltage is a low potential (GND potential) (step S3). Whether or not the sampled voltage is a low potential may be determined based on a predetermined threshold voltage. If the sampled voltage is not a low potential, it is regarded as a high potential (VCC potential). If the sampled voltage is a high potential, the counter n is cleared (n = 0), and the microcomputer 26 determines that the voltage state is the “normal state” (step S4). On the other hand, if the sampled voltage is a low potential, the counter n is counted up (n → n + 1) (step S5).
次にカウンタnがNs以上か否か判定する(ステップS6)。ここでNs値は過電圧継続状態判定閾値として、図示しないメモリ素子等に予め保持しておくか、マイコン26の処理プログラム内で規定しておけばよい。n≧Nsの場合は、連続してNs回以上分のサンプリング電圧が全て低電位であったことを意味する。入力ポート(IN-2)の入力電圧が低電位になるのは過電圧検出回路41aが過電圧状態を検出した場合であるから、n≧Nsになったということは、放電回路41bによる平滑コンデンサ24の放電を実施したにもかかわらず、少なくとも(Ns-1)×Ts時間にわたって過電圧状態が解消されなかったことを意味する。このような過電圧状態が継続している時間長を過電圧継続時間Tdとする。そして、マイコン26は過電圧継続時間Tdが(Ns-1)×Ts以上の時「過電圧継続状態」と判断する(ステップS7)。そして、「過電圧継続状態」と判断した時は、マイコン26の制御によりリレー7,17をそれぞれオフ状態にする。なお、リレー7,17が既にオフ状態になっている場合にはそれぞれのリレーのオフ状態を維持するようにする(ステップS8)。リレー7,17をオフ状態にして交流電源3からの電力を遮断することで、過電圧状態を解消するようにする。これはソフトウェア制御による過電圧解消動作である。ここで、リレー7,17による電力遮断を実施したことを図示しない表示装置により電力変換装置の利用者に過電圧継続状態の発生を通知してもよい。
Next, it is determined whether or not the counter n is greater than or equal to Ns (step S6). Here, the Ns value may be held in advance in a memory element (not shown) as an overvoltage continuation state determination threshold value, or may be defined in the processing program of the microcomputer 26. In the case of n ≧ Ns, it means that the sampling voltages for Ns times or more in succession were all at a low potential. Since the input voltage of the input port (IN-2) becomes a low potential when the overvoltage detection circuit 41a detects the overvoltage state, n ≧ Ns means that the smoothing capacitor 24 of the discharge circuit 41b This means that the overvoltage state has not been resolved for at least (Ns−1) × Ts time despite the discharge being performed. The length of time during which such an overvoltage state continues is defined as an overvoltage duration Td. Then, the microcomputer 26 determines that the “overvoltage continuation state” when the overvoltage continuation time Td is equal to or longer than (Ns−1) × Ts (step S7). When it is determined that the “overvoltage continuation state”, the relays 7 and 17 are turned off under the control of the microcomputer 26. If the relays 7 and 17 have already been turned off, the respective relays are kept off (step S8). The relays 7 and 17 are turned off to cut off the power from the AC power supply 3, thereby eliminating the overvoltage state. This is an overvoltage elimination operation by software control. Here, the occurrence of the overvoltage continuation state may be notified to the user of the power conversion device by a display device (not shown) that the power interruption by the relays 7 and 17 has been performed.
マイコン26は「過電圧継続状態」と判断するまでは、入力ポート(IN-2)の入力電圧をサンプリングする毎にステップS2~S6の処理を繰り返し実行する。図8の無効電力削減モード時の動作では、Ns=3とした場合の動作を例示している。この事例では、過電圧継続時間Tdが小さい為に、連続したNs回分のサンプリング電圧が全て低電位とはなっていないので、マイコン26は「過電圧継続状態」とは判断していない。なお、無効電力削減モード時にはリレー7,17は既にオフ状態で交流電源3からの交流電力は遮断されているので、マイコン26が「過電圧継続状態」と判断する状況は通常は発生しにくい。この為、交流電源3の電圧が瞬間的に変動した場合でも、過電圧保護回路41のハードウェア動作のみで過電圧状態を解消させることができる。
The microcomputer 26 repeatedly executes the processing of steps S2 to S6 every time the input voltage of the input port (IN-2) is sampled until it is determined as “overvoltage continuation state”. The operation in the reactive power reduction mode in FIG. 8 illustrates the operation when Ns = 3. In this example, since the overvoltage continuation time Td is small, the sampling voltages for the continuous Ns times are not all low potentials, so the microcomputer 26 does not determine that the “overvoltage continuation state”. In the reactive power reduction mode, the relays 7 and 17 are already in an off state and the AC power from the AC power supply 3 is cut off. Therefore, the situation in which the microcomputer 26 determines that the “overvoltage continuation state” is not likely to occur. For this reason, even when the voltage of the AC power supply 3 fluctuates instantaneously, the overvoltage state can be resolved only by the hardware operation of the overvoltage protection circuit 41.
[6]コンバータ主回路10の短絡故障時
次に過電圧状態が継続して、ソフトウェア制御による過電圧解消動作が実行されるケースについて動作を説明する。ここではコンバータ主回路10内部のスイッチング素子12aが短絡故障している状態で室外機1を起動した場合を例にして説明する。 [6] At the time of short-circuit failure of convertermain circuit 10 Next, the operation will be described for a case where the overvoltage state continues and the overvoltage elimination operation by software control is executed. Here, the case where the outdoor unit 1 is started in a state where the switching element 12a in the converter main circuit 10 is short-circuited will be described as an example.
次に過電圧状態が継続して、ソフトウェア制御による過電圧解消動作が実行されるケースについて動作を説明する。ここではコンバータ主回路10内部のスイッチング素子12aが短絡故障している状態で室外機1を起動した場合を例にして説明する。 [6] At the time of short-circuit failure of converter
室外機1が「停止」状態(ブレーカ4,リレー7,17はいずれもオフ状態にある。図2参照)にある時に、ブレーカ4をオフ状態からオン状態に切り替えることで、室外機1の動作モードを「起動(1)」状態へと移行させると、前述した図3及び図4の電流経路で交流電力が室外機1に供給され、平滑コンデンサ24が充電される。これにより、DC/DCコンバータ25からの直流電圧でマイコン26が起動する。
When the outdoor unit 1 is in the “stop” state (the breaker 4, the relays 7 and 17 are both in the off state, see FIG. 2), the operation of the outdoor unit 1 is performed by switching the breaker 4 from the off state to the on state. When the mode is shifted to the “start (1)” state, AC power is supplied to the outdoor unit 1 through the above-described current paths of FIGS. 3 and 4 and the smoothing capacitor 24 is charged. As a result, the microcomputer 26 is activated by the DC voltage from the DC / DC converter 25.
引き続いて、リレー17をオフ状態からオン状態に切り替えることで、室外機1の動作モードを「起動(2)」状態へと移行させると、交流電源3から室外機1に図10及び図11の経路でも電流が流れるようになる。ここで、図10は交流電源3の電圧位相が正の場合の電流経路を示し、図11は交流電源3の電圧位相が負の場合の電流経路を示している。
Subsequently, when the operation mode of the outdoor unit 1 is shifted to the “start (2)” state by switching the relay 17 from the off state to the on state, the AC power source 3 switches the outdoor unit 1 to the outdoor unit 1 as shown in FIGS. Current also flows through the path. Here, FIG. 10 shows a current path when the voltage phase of the AC power supply 3 is positive, and FIG. 11 shows a current path when the voltage phase of the AC power supply 3 is negative.
具体的には交流電源3の電圧位相が正の場合には図10に示すように、交流電源3→ノイズフィルタ5→PTCサーミスタ16→ダイオード18→主回路コンデンサ15→全波整流回路9→ノイズフィルタ5→交流電源3の経路で電流が流れる。これにより、主回路コンデンサ15が充電される。一方、交流電源3の電圧位相が負の場合には図11に示すように、交流電源3→ノイズフィルタ5→全波整流回路9→コンバータ主回路10→主回路コンデンサ15→ダイオード27→平滑コンデンサ24→ダイオード23→PTCサーミスタ21→ノイズフィルタ5→交流電源3の経路で電流が流れる。このときコンバータ主回路10はまだ昇圧動作を開始しておらず、スイッチング素子12a,12bはオン・オフ駆動されていないが、スイッチング素子12aが短絡故障している為にスイッチング素子12a内部が導通して、前述の経路で電流が流れるものである。これにより、主回路コンデンサ15の端子間電圧と交流電源3の電圧を加算した電圧が平滑コンデンサ24の端子間に印加されることで、平滑コンデンサ24の端子間に過電圧状態が発生する。以後、交流電源3の電圧周期毎に平滑コンデンサ24に対する昇圧動作が反復することで、平滑コンデンサ24の過電圧状態は継続して発生することになる。
Specifically, when the voltage phase of the AC power supply 3 is positive, as shown in FIG. 10, the AC power supply 3 → the noise filter 5 → the PTC thermistor 16 → the diode 18 → the main circuit capacitor 15 → the full wave rectifier circuit 9 → noise. A current flows through the path of the filter 5 → the AC power source 3. As a result, the main circuit capacitor 15 is charged. On the other hand, when the voltage phase of the AC power supply 3 is negative, as shown in FIG. 11, the AC power supply 3 → the noise filter 5 → the full wave rectifier circuit 9 → the converter main circuit 10 → the main circuit capacitor 15 → the diode 27 → the smoothing capacitor. A current flows through a path of 24 → diode 23 → PTC thermistor 21 → noise filter 5 → AC power supply 3. At this time, the converter main circuit 10 has not yet started the step-up operation, and the switching elements 12a and 12b are not driven on / off. However, since the switching element 12a is short-circuited, the inside of the switching element 12a becomes conductive. Thus, current flows through the above-described path. As a result, a voltage obtained by adding the voltage between the terminals of the main circuit capacitor 15 and the voltage of the AC power supply 3 is applied between the terminals of the smoothing capacitor 24, thereby generating an overvoltage state between the terminals of the smoothing capacitor 24. Thereafter, the voltage boosting operation for the smoothing capacitor 24 is repeated every voltage cycle of the AC power supply 3, and the overvoltage state of the smoothing capacitor 24 continues to occur.
この現象が発生した時の過電圧保護回路41の動作を図12及び図13で説明する。図12及び図13は室外機1の動作モードが「起動(1)」状態から「起動(2)」状態に遷移する時の過電圧保護回路41の動作タイミングを図7及び図8と同様に示したものである。
The operation of the overvoltage protection circuit 41 when this phenomenon occurs will be described with reference to FIGS. 12 and 13 show the operation timing of the overvoltage protection circuit 41 when the operation mode of the outdoor unit 1 transitions from the “start (1)” state to the “start (2)” state, as in FIGS. 7 and 8. It is a thing.
前述したように起動(1)モードで動作中にはリレー17及びリレー7はオフ状態にある。ここで、リレー17をオン状態に切り換える(時間T11)ことにより起動(2)モードに移行すると、交流電源3の電圧位相に対応して図10及び図11に示した電流経路で電流が流れることで平滑コンデンサ24に過電圧が印加され、平滑コンデンサ24の端子間電圧が上昇する。そして、平滑コンデンサ24の端子間電圧が、過電圧検出の判定電圧閾値Vth1より大きくなると(時間T12)、スイッチング素子32がターンオンする。
As described above, the relay 17 and the relay 7 are in an off state during operation in the start (1) mode. Here, when switching to the start (2) mode by switching the relay 17 to the ON state (time T11), a current flows in the current path shown in FIGS. 10 and 11 corresponding to the voltage phase of the AC power supply 3. Thus, an overvoltage is applied to the smoothing capacitor 24, and the voltage across the terminals of the smoothing capacitor 24 increases. When the inter-terminal voltage of the smoothing capacitor 24 becomes larger than the determination voltage threshold Vth1 for overvoltage detection (time T12), the switching element 32 is turned on.
スイッチング素子32がオン状態になった後、引き続いて放電用のスイッチング素子38がターンオンする(時間T13)とともに、フォトカプラ35もターンオンする。スイッチング素子38がオン状態になることで、平滑コンデンサ24から抵抗39を経由して放電電流が流れる。また、フォトカプラ35がオン状態になることで、マイコン26の入力ポート(IN-2)には低電位(GND電位)が入力され、マイコン26は平滑コンデンサ24の端子間が過電圧状態であることを認識する。
After the switching element 32 is turned on, the discharge switching element 38 is subsequently turned on (time T13), and the photocoupler 35 is also turned on. When the switching element 38 is turned on, a discharge current flows from the smoothing capacitor 24 via the resistor 39. Further, when the photocoupler 35 is turned on, a low potential (GND potential) is input to the input port (IN-2) of the microcomputer 26, and the microcomputer 26 is in an overvoltage state between the terminals of the smoothing capacitor 24. Recognize
時間T13以後は、放電回路41bが動作することで平滑コンデンサ24の電荷は放電されるものの、交流電源3の電圧周期で昇圧動作が繰り返される為、平滑コンデンサ24は図10及び図11に示した電流経路で繰り返し充電される。この為、平滑コンデンサ24の端子間電圧は依然として増加し続ける。
After time T13, the electric charge of the smoothing capacitor 24 is discharged by the operation of the discharge circuit 41b. However, the step-up operation is repeated in the voltage cycle of the AC power supply 3, and therefore, the smoothing capacitor 24 is shown in FIGS. It is repeatedly charged in the current path. For this reason, the voltage between the terminals of the smoothing capacitor 24 continues to increase.
この為、マイコン26の入力ポート(IN-2)の入力電圧は低電位である時間が長くなる。そして、マイコン26の入力ポート(IN-2)の入力電圧をサンプリングした電圧がNs回(ここではNs=3)連続して低電位となった時点(時間T14)で、「過電圧継続状態」であると判断し、リレー17をオン状態からオフ状態に切り替える。なお、起動(2)モードではリレー7はオフ状態であるので、このオフ状態を維持するようにする。なお、誤動作等の理由でリレー7がオン状態にあった場合には、リレー7もオフ状態に切り替える。リレー17がオフ状態になることにより、平滑コンデンサ24の充電経路が遮断される。そして、放電回路41bによる平滑コンデンサ24の放電は継続することで、平滑コンデンサ24の端子間電圧は部品の耐圧レベルに到達する前に低下していく。このようにして過電圧で部品故障になることを防止することができる。
Therefore, the time during which the input voltage of the input port (IN-2) of the microcomputer 26 is low is long. Then, when the voltage obtained by sampling the input voltage of the input port (IN-2) of the microcomputer 26 is continuously at a low potential Ns times (here, Ns = 3) (time T14), it is in the “overvoltage continuation state”. The relay 17 is switched from the on state to the off state. Since the relay 7 is in the off state in the start (2) mode, the off state is maintained. In addition, when the relay 7 is in an on state due to a malfunction or the like, the relay 7 is also switched to an off state. When the relay 17 is turned off, the charging path of the smoothing capacitor 24 is interrupted. And the discharge of the smoothing capacitor 24 by the discharge circuit 41b continues, so that the voltage across the terminals of the smoothing capacitor 24 decreases before reaching the withstand voltage level of the component. In this way, it is possible to prevent a component failure due to overvoltage.
平滑コンデンサ24の端子間電圧が、過電圧検出の判定電圧閾値Vth1より小さくなると(時間T15)、スイッチング素子32がターンオフし、引き続いて放電用のスイッチング素子38及びフォトカプラ35もターンオフする(時間T16)。これにより、マイコン26の入力ポート(IN-2)の入力電圧は高電位に変化するが、マイコン26は室外機1を含む空気調和機全体を再起動するまでリレー17のオフ状態を維持する。
When the voltage between the terminals of the smoothing capacitor 24 becomes smaller than the determination voltage threshold Vth1 for overvoltage detection (time T15), the switching element 32 is turned off, and then the discharge switching element 38 and the photocoupler 35 are also turned off (time T16). . Thereby, although the input voltage of the input port (IN-2) of the microcomputer 26 changes to a high potential, the microcomputer 26 maintains the relay 17 in the OFF state until the entire air conditioner including the outdoor unit 1 is restarted.
その後、マイコン26は空気調和機システム全体を再起動することで、「停止」状態の動作モードから処理を再開する。空気調和機システムの再起動後も同様にマイコン26が「過電圧継続状態」を検出した場合には再度再起動を行う。Nf回連続して再起動後に「過電圧継続状態」を検出した場合には、過電圧状態の発生が一時的なものではなく、コンバータ主回路10の故障である可能性が高いので、それ以降の再起動処理を停止させる。なおNf値はシステム故障判定閾値として、図示しないメモリ素子等に予め保持しておくか、マイコン26の処理プログラム内で規定しておけばよい。
Thereafter, the microcomputer 26 restarts the entire air conditioner system, thereby restarting the process from the operation mode in the “stop” state. Similarly, after the air conditioner system is restarted, when the microcomputer 26 detects the “overvoltage continuation state”, it restarts again. When the “overvoltage continuation state” is detected after restarting Nf times continuously, the occurrence of the overvoltage state is not temporary, and there is a high possibility that the converter main circuit 10 is faulty. Stop the startup process. The Nf value may be stored in advance in a memory element (not shown) as a system failure determination threshold value or may be defined in the processing program of the microcomputer 26.
以上説明したように、無効電力削減モード移行時や、コンバータ主回路10の短絡故障時等に平滑コンデンサ24の端子間電圧が過電圧状態になっても過電圧検出回路41aが過電圧状態を検出し、放電回路41bが平滑コンデンサ24の電荷を放電するように過電圧保護回路41を構成したので、平滑コンデンサ24の端子間電圧が部品耐圧を超えない電圧レベルに抑えることが可能である。
As described above, the overvoltage detection circuit 41a detects the overvoltage state even if the voltage between the terminals of the smoothing capacitor 24 becomes an overvoltage state at the time of transition to the reactive power reduction mode or at the time of a short circuit failure of the converter main circuit 10, etc. Since the overvoltage protection circuit 41 is configured so that the circuit 41b discharges the electric charge of the smoothing capacitor 24, the voltage between the terminals of the smoothing capacitor 24 can be suppressed to a voltage level that does not exceed the component breakdown voltage.
また、放電回路41bによる放電を行っても過電圧状態が解消しない場合には、マイコン26の制御によりリレー7及びリレー17をオフ状態にすることで、平滑コンデンサ24の充電経路、及びコンバータ主回路10への通電経路が遮断されるので、このような場合でも平滑コンデンサ24の端子間電圧が部品耐圧を超えない電圧レベルに抑えることが可能であるとともに、コンバータ主回路10を含む回路部品を過電圧による部品故障から保護することができる。
If the overvoltage state is not eliminated even after discharging by the discharge circuit 41b, the charging path of the smoothing capacitor 24 and the converter main circuit 10 are turned off by turning off the relay 7 and the relay 17 under the control of the microcomputer 26. Even in such a case, the voltage between the terminals of the smoothing capacitor 24 can be suppressed to a voltage level that does not exceed the component withstand voltage, and the circuit components including the converter main circuit 10 are caused by overvoltage. It can protect against component failure.
なお、以上の説明では本発明の電力変換装置を空気調和機に適用した例で説明したが、その他の家電機器、産業用機器に適用することも可能である。
In addition, in the above description, although the power converter device of this invention was demonstrated in the example applied to the air conditioner, it is also possible to apply to other household appliances and industrial equipment.
1 室外機
2 室内機
3 交流電源
4 ブレーカ(BR)
5,6 ノイズフィルタ
7,17 リレー
8 コンデンサ
9 全波整流回路
10 コンバータ主回路
15 主回路コンデンサ
16,21 PTCサーミスタ
18 逆流防止用ダイオード
19 インバータ主回路
20 モータ
24 平滑コンデンサ
25 DC/DCコンバータ
26 マイコン
40 出力電圧検出部
41 過電圧保護回路
41a 過電圧検出回路
41b 放電回路 1Outdoor unit 2 Indoor unit 3 AC power supply 4 Breaker (BR)
5,6 Noise filter 7, 17 Relay 8 Capacitor 9 Full wave rectifier circuit 10 Converter main circuit 15 Main circuit capacitor 16, 21 PTC thermistor 18 Backflow prevention diode 19 Inverter main circuit 20 Motor 24 Smoothing capacitor 25 DC / DC converter 26 Microcomputer 40 Output Voltage Detection Unit 41 Overvoltage Protection Circuit 41a Overvoltage Detection Circuit 41b Discharge Circuit
2 室内機
3 交流電源
4 ブレーカ(BR)
5,6 ノイズフィルタ
7,17 リレー
8 コンデンサ
9 全波整流回路
10 コンバータ主回路
15 主回路コンデンサ
16,21 PTCサーミスタ
18 逆流防止用ダイオード
19 インバータ主回路
20 モータ
24 平滑コンデンサ
25 DC/DCコンバータ
26 マイコン
40 出力電圧検出部
41 過電圧保護回路
41a 過電圧検出回路
41b 放電回路 1
5,6
Claims (5)
- 交流電源の交流電圧を整流して直流電圧を出力する第1の整流回路と、
前記第1の整流回路の直流電圧出力を変換して変換後の直流電圧を出力するコンバータ主回路と、
前記コンバータ主回路の直流電圧出力を平滑する主回路コンデンサと、
前記交流電源と前記第1の整流回路間の交流電圧経路に設けられた第1の開閉手段と、
前記第1の開閉手段の交流電源側端子と前記主回路コンデンサの正極端子間に直列接続された第2の開閉手段及び逆流防止用ダイオードと、
コンデンサを有し、前記交流電源の交流電圧を整流して直流電圧を出力する第2の整流回路と、
前記第2の整流回路が出力する直流電圧に基づき過電圧状態を検出する過電圧検出回路と、
前記過電圧検出回路が過電圧状態を検出した際に、前記整流回路のコンデンサの電荷を放電する放電回路と、
前記過電圧検出回路が検出した過電圧状態に基づき、前記第1の開閉手段及び前記第2の開閉手段を制御する制御手段とを備え、
前記制御手段は、前記過電圧状態が所定の時間以上継続した際には、閉状態にある前記第1の開閉手段及び前記第2の開閉手段を開放することを特徴とする電力変換装置。 A first rectifier circuit that rectifies an AC voltage of an AC power source and outputs a DC voltage;
A converter main circuit for converting the DC voltage output of the first rectifier circuit and outputting the converted DC voltage;
A main circuit capacitor for smoothing the DC voltage output of the converter main circuit;
First opening / closing means provided in an AC voltage path between the AC power source and the first rectifier circuit;
A second switching means and a backflow prevention diode connected in series between the AC power supply side terminal of the first switching means and the positive terminal of the main circuit capacitor;
A second rectifier circuit having a capacitor and rectifying an AC voltage of the AC power supply to output a DC voltage;
An overvoltage detection circuit for detecting an overvoltage state based on a DC voltage output from the second rectifier circuit;
A discharge circuit for discharging the charge of the capacitor of the rectifier circuit when the overvoltage detection circuit detects an overvoltage state;
Control means for controlling the first opening and closing means and the second opening and closing means based on the overvoltage state detected by the overvoltage detection circuit;
The control means opens the first opening / closing means and the second opening / closing means in a closed state when the overvoltage state continues for a predetermined time or longer. - 前記過電圧検出回路は、前記第2の整流回路が出力する直流電圧が所定の電圧閾値より大きい時に過電圧状態と判断することを特徴とする請求項1に記載の電力変換装置。 The power converter according to claim 1, wherein the overvoltage detection circuit determines an overvoltage state when a DC voltage output from the second rectifier circuit is greater than a predetermined voltage threshold.
- 前記制御手段は、閉状態にある前記第1の開閉手段又は前記第2の開閉手段を開放した後に、再起動を実行することを特徴とする請求項1又は2に記載の電力変換装置。 3. The power conversion apparatus according to claim 1, wherein the control means executes restart after opening the first opening / closing means or the second opening / closing means in a closed state.
- 前記コンバータ主回路は、スイッチング素子を用いた力率改善コンバータであることを特徴とする請求項1~3のいずれか一つに記載の電力変換装置。 The power converter according to any one of claims 1 to 3, wherein the converter main circuit is a power factor correction converter using a switching element.
- 請求項1~4のいずれか一つに記載の電力変換装置を備えることを特徴とする空気調和機。 An air conditioner comprising the power conversion device according to any one of claims 1 to 4.
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018216655A1 (en) * | 2017-05-25 | 2018-11-29 | パナソニック アプライアンシズ リフリジレーション デヴァイシズ シンガポール | Compressor driving device, control unit using same, compressor unit, and cooler |
JP2019054633A (en) * | 2017-09-14 | 2019-04-04 | 新電元工業株式会社 | Electric power supply, semiconductor integrated circuit, and control method of the electric power supply |
CN113541106A (en) * | 2021-05-28 | 2021-10-22 | 国网浙江省电力有限公司营销服务中心 | Capacitor protection circuit of breaker power supply |
US20210388791A1 (en) * | 2020-06-10 | 2021-12-16 | Denso Corporation | Injection control device |
JP2022113826A (en) * | 2017-03-28 | 2022-08-04 | ダイキン工業株式会社 | heat source unit |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR102192789B1 (en) * | 2019-02-25 | 2020-12-18 | 엘지전자 주식회사 | Power converting apparatus and air conditioner including the same |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010178540A (en) * | 2009-01-30 | 2010-08-12 | Toshiba Mitsubishi-Electric Industrial System Corp | Power converter |
JP2015096009A (en) * | 2013-11-14 | 2015-05-18 | ローム株式会社 | Ac/dc converter, its protection circuit, power-supply circuit, power-supply adapter, and electronic apparatus |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5281471B2 (en) * | 2009-04-24 | 2013-09-04 | パナソニック株式会社 | Power supply |
JP5424031B2 (en) * | 2009-08-31 | 2014-02-26 | サンケン電気株式会社 | Power factor correction circuit |
JP5052590B2 (en) * | 2009-12-16 | 2012-10-17 | 三菱電機株式会社 | Power supply circuit and lighting device |
JP5761301B2 (en) * | 2013-10-25 | 2015-08-12 | 三菱電機株式会社 | Lighting device and lighting apparatus |
-
2015
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Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010178540A (en) * | 2009-01-30 | 2010-08-12 | Toshiba Mitsubishi-Electric Industrial System Corp | Power converter |
JP2015096009A (en) * | 2013-11-14 | 2015-05-18 | ローム株式会社 | Ac/dc converter, its protection circuit, power-supply circuit, power-supply adapter, and electronic apparatus |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2022113826A (en) * | 2017-03-28 | 2022-08-04 | ダイキン工業株式会社 | heat source unit |
WO2018216655A1 (en) * | 2017-05-25 | 2018-11-29 | パナソニック アプライアンシズ リフリジレーション デヴァイシズ シンガポール | Compressor driving device, control unit using same, compressor unit, and cooler |
JP2019054633A (en) * | 2017-09-14 | 2019-04-04 | 新電元工業株式会社 | Electric power supply, semiconductor integrated circuit, and control method of the electric power supply |
US20210388791A1 (en) * | 2020-06-10 | 2021-12-16 | Denso Corporation | Injection control device |
US11808228B2 (en) * | 2020-06-10 | 2023-11-07 | Denso Corporation | Injection control device |
CN113541106A (en) * | 2021-05-28 | 2021-10-22 | 国网浙江省电力有限公司营销服务中心 | Capacitor protection circuit of breaker power supply |
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