WO2015104922A1 - 電力変換装置 - Google Patents
電力変換装置 Download PDFInfo
- Publication number
- WO2015104922A1 WO2015104922A1 PCT/JP2014/081951 JP2014081951W WO2015104922A1 WO 2015104922 A1 WO2015104922 A1 WO 2015104922A1 JP 2014081951 W JP2014081951 W JP 2014081951W WO 2015104922 A1 WO2015104922 A1 WO 2015104922A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- arm
- voltage
- command
- negative
- positive
- Prior art date
Links
Images
Classifications
-
- 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
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/483—Converters with outputs that each can have more than two voltages levels
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
-
- 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
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
-
- 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
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/483—Converters with outputs that each can have more than two voltages levels
- H02M7/4835—Converters with outputs that each can have more than two voltages levels comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage
-
- 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
- H02M7/66—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal
- H02M7/68—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters
-
- 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
- H02M7/66—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal
- H02M7/68—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters
- H02M7/72—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/75—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with 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
- H02M7/77—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with 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 arranged for operation in parallel
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0009—Devices or circuits for detecting current in a converter
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0025—Arrangements for modifying reference values, feedback values or error values in the control loop of a converter
Definitions
- the present invention relates to a power converter that performs power conversion between a plurality of phases of alternating current and direct current, and more particularly to a large-capacity power converter that multiplexes converters.
- One method of multiplexing the converters is a multilevel converter in which the outputs of a plurality of converters are cascade-connected, and one of them is a modular multilevel converter. Each arm of the modular multilevel converter is configured by cascading a plurality of converter cells.
- the first arm and the second arm of each phase of the conventional modular multilevel converter each include a chopper cell (converter cell) and a reactor.
- a chopper cell inverter cell
- two semiconductor switches are connected in series, and a DC capacitor is connected in parallel.
- the same number of chopper cells are cascade-connected via respective output terminals.
- the control of each phase of the conventional modular multilevel converter includes the average value control in which the average value of the voltage values of all DC capacitors follows the capacitor voltage command value, and the voltage value of each DC capacitor to the capacitor voltage command value.
- the present invention has been made to solve the above-described problems, and is a power converter that can be stably and reliably controlled even when inductance components are different between a positive arm and a negative arm.
- the purpose is to obtain.
- the power conversion device includes a plurality of leg circuits in which a positive arm and a negative arm are connected in series and a connection point is connected to each phase AC line in parallel between the positive and negative DC buses. And a power converter that performs power conversion between a plurality of phases of alternating current and direct current, and a control device that controls the power converter.
- Each of the positive side arm and the negative side arm of each leg circuit includes a series body of a plurality of semiconductor switching elements connected in series to each other and a DC capacitor connected in parallel to the series body.
- One or a plurality of converter cells having terminals as output terminals are connected in series, and the control device generates a first voltage command for the positive arm and a second voltage command for the negative arm.
- a command generation unit is provided to control output of each of the converter cells in the positive side arm and the negative side arm.
- the voltage command generation unit includes a current control unit that calculates a control command for controlling an alternating current component flowing through each phase AC line and a circulating current component of each phase that circulates between the leg circuits, and the control command. And the DC voltage command value of the voltage between the DC buses, the voltages generated by the inductance components in the positive arm and the negative arm from the voltages shared by the positive arm and the negative arm, respectively. And a command distribution unit that subtracts the drop and determines the first voltage command and the second voltage command.
- the first voltage command for the positive side arm and the second voltage command for the negative side arm can be accurately obtained. It can be generated and controlled stably and reliably.
- FIG. 1 is a schematic configuration diagram of a power conversion device according to Embodiment 1 of the present invention.
- the power conversion device includes a power converter 1 that is a main circuit, and a control device 20 that controls the power converter 1.
- the power converter 1 performs multi-phase AC, in this case, power conversion between three-phase AC and DC, and the AC side is connected to an AC power source 14 which is a system as an AC circuit via an interconnection transformer 13.
- the DC side is connected to the DC power supply 16 via the impedance 15.
- you may connect to the alternating current power supply 14 via a connection reactor instead of the connection transformer 13.
- the DC side of the power converter 1 may be connected to a DC load, or may be connected to another power converter that performs DC output.
- Each phase of the power converter 1 includes a leg circuit 4 in which a positive arm 5 and a negative arm 6 are connected in series, and an AC terminal 7 that is a connection point thereof is connected to each phase AC line.
- the circuit 4 is connected in parallel between the positive and negative DC buses 2 and 3.
- Each of the positive side arm 5 and the negative side arm 6 of each leg circuit 4 includes cell groups 5a and 6a in which one or more converter cells 10 are connected in series, and a positive side reactor 9p and a negative side reactor 9n are respectively connected in series. Inserted into.
- the positive side reactor 9p and the negative side reactor 9n are connected to the AC terminal 7 side, and the positive side reactor 9p and the negative side reactor 9n constitute a three-terminal reactor 8.
- the position where the positive side reactor 9p and the negative side reactor 9n are inserted may be any position in each of the arms 5 and 6, and may be plural.
- control device 20 includes a voltage command generation unit 21 that generates a positive arm voltage command Vp + that is a first voltage command and a negative arm voltage command Vp ⁇ that is a second voltage command, and a PWM circuit 22. And generate a gate signal 22a to control each converter cell 10 in the positive arm 5 and the negative arm 6 of each phase.
- the positive arm current ip + and negative arm current ip ⁇ flowing in the positive arm 5 and the negative arm 6 of each phase, respectively, and the AC current ip flowing in each phase AC line are detected by current detectors (not shown). Input to the control device 20.
- each phase voltage of the AC power supply 14 (hereinafter referred to as AC voltage Vsp) detected by a voltage detector (not shown), the neutral point voltage Vsn of the power converter 1, and the voltage of the DC power supply 16 that is the DC bus voltage.
- Command value (hereinafter referred to as DC voltage command value Vdc) is input to the control device 20.
- the alternating current ip of each phase may be calculated from the positive arm current ip + and the negative arm current ip ⁇ flowing through the positive arm 5 and the negative arm 6 of each phase, respectively.
- the voltage command generation unit 21 performs a positive arm voltage command Vp + for the positive arm 5 of each phase and a negative value for the negative arm 6 of each phase.
- side arm voltage command Vp - generates the.
- the PWM circuit 22 generates a gate signal 22a by pulse width modulation control (PWM control) based on the voltage commands Vp + and Vp ⁇ . Details of the configuration and operation of the control device 20 will be described later.
- FIG. 2 shows a transducer cell 10 employing a half bridge configuration.
- the converter cell 10 of FIG. 2 includes a series body 32 of a plurality (in this case, two) of semiconductor switching elements 30 (hereinafter simply referred to as switching elements) each having a diode 31 connected in antiparallel, and the series body 32. And a DC capacitor 34 connected in parallel to smooth the DC voltage.
- the switching element 30 is composed of a self-extinguishing type switching element such as an IGBT (Insulated Gate Bipolar Transistor) or a GCT (Gate Commutated Turn-off thyristor), and switches 33P and 33N each having a diode 31 connected in antiparallel are used.
- IGBT Insulated Gate Bipolar Transistor
- GCT Gate Commutated Turn-off thyristor
- the converter cell 10 uses both terminals of the switching element 30 of the switch 33N as output ends, and turns the switching element 30 on and off so that both ends of the DC capacitor 34 are connected from this output end. Output voltage and zero voltage.
- FIG. 3 shows a converter cell 10 employing a full bridge configuration.
- the converter cell 10 of FIG. 3 includes a DC capacitor 44 that connects two series bodies 42 in parallel, and is connected in parallel to the series body 42 to smooth the DC voltage.
- Each series body 42 is configured by connecting in series a plurality of (in this case, two) switching elements 40 each having a diode 41 connected in antiparallel.
- the switching element 40 is formed of a self-extinguishing type switching element such as IGBT or GCT, and switches 43P and 43N each including a diode 41 connected in antiparallel are used. As shown in FIG.
- the converter cell 10 uses the terminal of the switching element 40 serving as an intermediate connection point of each series body 42 as an output terminal, and turns the switching element 40 on and off to thereby output this output terminal. To output a positive voltage, a negative voltage, and a zero voltage across the DC capacitor 44.
- the converter cell 10 is composed of a series body of a plurality of switching elements and a DC capacitor connected in parallel to the series body. If the converter cell 10 is configured to selectively output the voltage of the DC capacitor by a switching operation, The configuration is not limited to that shown in FIGS.
- FIG. 4 is a block diagram illustrating a configuration example of the control device 20.
- the control device 20 includes the voltage command generation unit 21 and the PWM circuit 22 as described above.
- the voltage command generator 21 controls the current of an alternating current controller 23 for controlling the alternating current ip and a circulating current controller 24 for controlling the circulating current izp of each phase circulating in the power converter 1.
- provided as part further phases of the positive-side arm voltage command Vp + and the negative-side arm voltage command Vp - comprises an instruction distributing unit 25 for determining the.
- the alternating current control unit 23 calculates a first control command Vcp, which is a voltage command, so that the deviation between the detected alternating current ip and the set alternating current command becomes zero. That is, the first control command Vcp for controlling the alternating current ip flowing through each phase AC line to follow the alternating current command is calculated.
- the circulating current control unit 24 calculates a second control command Vzp, which is a voltage command, so that a deviation from the circulating current command izp of each phase and a set circulating current command, for example, 0, becomes zero. That is, the second control command Vzp for controlling the circulating current izp of each phase to follow the circulating current command is calculated.
- the circulating current izp of each phase can be calculated from the positive arm current ip + and the negative arm current ip ⁇ that flow in the positive arm 5 and the negative arm 6 of each phase, respectively.
- the command distribution unit 25 receives the calculated first control command Vcp, second control command Vzp, DC voltage command value Vdc, and neutral point voltage Vsn, and further, the AC voltage of each phase as a feed forward term.
- Vsp is input.
- the neutral point voltage Vsn is calculated by the voltage of the DC power supply 16.
- the DC voltage command value Vdc may be given by DC output control or may be a constant value.
- neutral point voltage Vsn is calculated from AC voltage Vsp and DC power supply 16 voltage.
- the command distribution unit 25 subtracts the voltage drop due to the inductance component in each arm 5 and 6 from the voltage shared by the positive arm 5 and the negative arm 6, respectively. by distributing the components, the positive-side arm voltage command value Vp + for positive-side arm 5 of each phase, the negative-side arm voltage command value Vp for each phase of the negative-side arm 6 - to determine that.
- the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ of each phase generated by the voltage command generation unit 21 follow the alternating current ip to the alternating current command and the circulating current izp to the circulating current command, respectively.
- the voltage of the DC power supply 16 is controlled to the DC voltage command value Vdc, and further, the output voltage command is a feedforward control of the AC voltage Vsp.
- the PWM circuit 22 performs a PWM control on each converter cell 10 in the positive arm 5 and the negative arm 6 of each phase based on the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ . Is generated.
- the switching element 30 (40) in each converter cell 10 is driven and controlled by the generated gate signal 22a, and the output voltage of the power converter 1 is controlled to a desired value.
- FIG. 5 is a diagram showing the voltage and current of each part in one phase of the power converter 1 on the circuit.
- Lac represents the inductance of the interconnection transformer 13
- Lc + represents the inductance of the positive side reactor 9p
- Lc ⁇ represents the inductance of the negative side reactor 9n.
- Positive arm voltage command Vp + is a command value of a voltage cell group 5a connected in series to the converter cell 10 of the positive-side arm 5 is output
- the negative-side arm voltage command Vp - is in the negative-side arm 6
- Is a command value of the voltage output from the cell group 6a in which the converter cells 10 are connected in series In this case, it is assumed that the output voltages of the cell groups 5a and 6a are controlled to Vp + and Vp ⁇ . Further, it is assumed that the voltage of the DC power supply 16 is also controlled to the DC voltage command value Vdc.
- ip ip + ⁇ ip ⁇
- Equation (1) and Equation (2) Substituting Equation (1) and Equation (2) into Equation (3) and Equation (4), erasing ip + and ip ⁇ and organizing the time derivative of current,
- the voltages Vp + and Vp ⁇ are the voltage components Vp + (i) and Vp ⁇ (i) necessary for controlling the current, and the voltage component Vp + ( It can be seen that it can be decomposed into v) and Vp ⁇ (v).
- Vp + (v) and Vp ⁇ (v) for controlling the voltage are obtained from the equation (5):
- Vp + (i) and Vp ⁇ (i) for controlling the current are obtained from the equation (6):
- the first control command Vcp for controlling the alternating current ip to follow the alternating current command and the second control command Vzp for controlling the circulating current izp to follow the circulating current command are made non-interfering, and the alternating current control and the circulation are made.
- the first control command Vcp and the second control command Vzp may be in the form of the following formula (9) from the formula (8).
- the equation (8) becomes the following equation (10), and the alternating current ip is independently controlled by the first control command Vcp and the circulating current izp is independently controlled by the second control command Vzp.
- the control object of the alternating current control is Lac + Lc + ⁇ Lc ⁇ / (Lc + + Lc ⁇ )
- the control target of the circulating current control is Lc + + Lc ⁇ It is.
- the first control command Vcp does not consider the voltage drop due to the parallel inductance component.
- the command distribution unit 25 uses the voltages Vp + and Vp ⁇ represented by the equation (12) as the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ .
- the positive side arm voltage command Vp + and the negative side arm voltage command Vp ⁇ satisfy the expression (3), that is, from the voltages shared by the positive side arm 5 and the negative side arm 6 respectively, This is the voltage obtained by subtracting the voltage drop due to the inductance component.
- the inductance component taking into account the voltage drop is obtained by removing the parallel inductance components of the arms 5 and 6.
- the voltage component related to the first control command Vcp for controlling the alternating current ip is a voltage obtained by multiplying the first control command Vcp by a coefficient. Since the alternating current ip flows to the interconnection transformer 13, the positive reactor 9p, and the negative reactor 9n, the coefficient of the first control command Vcp is the inductance of the interconnection transformer 13, the positive reactor 9p, and the negative reactor 9n. It is obtained from Lac, Lc + , Lc ⁇ .
- the positive-side arm voltage command Vp +, coefficients of a negative polarity is used for the first control command Vcp
- the negative-side arm voltage command Vp - relative to the first control command Vcp coefficient of the positive polarity is used It is done. Since the alternating current ip flows through the positive arm 5 and the negative arm 6 in the opposite directions, the voltage component related to the first control command Vcp has a reverse polarity between the positive arm 5 and the negative arm 6.
- the voltage component related to the second control command Vzp for controlling the circulating current izp is a voltage obtained by multiplying the second control command Vzp by a coefficient. Since the circulating current izp flowing between the positive side arm 5 and the negative side arm 6 flows to the positive side reactor 9p and the negative side reactor 9n, the coefficients of the second control command Vzp are the positive side reactor 9p and the negative side reactor 9n. The respective inductances Lc + and Lc ⁇ are obtained. A coefficient having the same polarity is used for the second control command Vzp with respect to the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ . Since the circulating current izp flows through the positive arm 5 and the negative arm 6 in the same direction, the voltage component related to the second control command Vzp has the same polarity in the positive arm 5 and the negative arm 6.
- the voltage component related to the DC voltage command value Vdc is only the voltage with respect to the positive side arm 5 and the coefficient is 1.
- the voltage drop caused by the inductance component in each arm 5 and 6 is subtracted from the voltage shared by the positive side arm 5 and the negative side arm 6 of the power converter 1, respectively.
- the positive-side arm voltage command value Vp + for positive-side arm 5 of each phase the negative-side arm voltage command value Vp for each phase of the negative-side arm 6 - to determine that.
- FIG. 6 is a schematic configuration diagram of a power conversion device according to Embodiment 2 of the present invention.
- each of the positive side arm 5 and the negative side arm 6 of each leg circuit 4 includes cell groups 5a and 6a in which one or more converter cells 10 are connected in series, and only the negative side arm 6 is provided.
- a negative reactor 9n is inserted in series on the negative electrode side of the cell group 6a.
- Other configurations are the same as those of the first embodiment shown in FIG. In FIG. 6, the control device 20 is not shown for convenience.
- control device 20 The configuration of the control device 20 is the same as that of the first embodiment shown in FIG. 4, but in this case, since there is no positive side reactor 9p, the calculation in the command distribution unit 25 is different and will be described below.
- the inductance Lc + is set to 0 and the equation (12) in the first embodiment is modified, the following equation (13) is obtained.
- the command distribution unit 25 uses the voltages Vp + and Vp ⁇ represented by the equation (13) as the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ .
- Vp + and Vp ⁇ represented by Expression (13) the voltage component related to the first control command Vcp for controlling the alternating current ip is a voltage obtained by multiplying the first control command Vcp by a coefficient.
- the alternating current ip flows through the positive arm 5 and the negative arm 6 in opposite directions, and a negative coefficient is used for the first control command Vcp with respect to the positive arm voltage command Vp + .
- vp - respect the coefficient of the positive polarity is used for the first control command Vcp.
- the magnitude of the coefficient for the positive side arm 5 is 1.
- the voltage component related to the second control command Vzp for controlling the circulating current izp is a voltage obtained by multiplying the second control command Vzp by a coefficient.
- the voltage component related to the second control command Vzp is only the voltage component for the negative side arm 6 and becomes ⁇ Vzp.
- the voltage components relating to AC voltage Vsp, neutral point voltage Vsn, and DC voltage command value Vdc are the same as those in the first embodiment. There is no difference between the voltages shared by these components due to inductance components.
- the command distribution unit 25 uses the voltages shared by the positive side arm 5 and the negative side arm 6 of the power converter 1, respectively, in each arm 5, 6 By subtracting the voltage drop due to the inductance component, and distributing the voltage component, the positive arm voltage command Vp + for the positive arm 5 of each phase and the negative arm voltage command for the negative arm 6 of each phase Vp - to determine that. Moreover, in the leg circuit 4 of each phase of the power converter 1, a reactor (negative reactor 9n) is inserted only in the negative electrode side of the cell group 6a of the negative arm 6.
- the negative reactor 9n may be a small element having a low withstand voltage characteristic, and the power converter 1 has a configuration suitable for downsizing.
- the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ of the power converter 1 suitable for downsizing are generated with high reliability, and the current control of the alternating current ip and the current control of the circulating current izp are performed.
- the power converter 1 is stably and reliably controlled without causing any interference between the two.
- the negative side reactor 9n may be inserted on the positive side of the cell group 6a of the negative side arm 6, and the control device 20 may control the positive side arm voltage command Vp + and the negative side arm as in the second embodiment.
- a voltage command Vp ⁇ is generated to control the power converter 1.
- FIG. 7 is a block diagram illustrating a configuration example of the control device 20 according to the third embodiment.
- the control device 20 includes a voltage command generation unit 21 a that generates a positive arm voltage command Vp + and a negative arm voltage command Vp ⁇ , and a PWM circuit 22, generates a gate signal 22 a, and controls the positive side of each phase
- the converter cells 10 in the arm 5 and the negative arm 6 are controlled.
- the sex point voltage Vsn and the DC voltage command value Vdc are input to the voltage command generator 21 a of the control device 20.
- the voltage command generation unit 21a includes an arm current control unit 26 for controlling the positive side arm current ip + and the negative side arm current ip ⁇ as a current control unit, and further includes a positive side arm voltage command Vp + for each phase. and a command distribution unit 25a which determines a - negative-side arm voltage command Vp.
- the arm current control unit 26 is a third control command Vpp which is a voltage command so that the deviation between the detected positive arm current ip + and negative arm current ip ⁇ and each set arm current command becomes 0, respectively.
- the fourth control command Vnp is calculated. That is, the third control command Vpp and the fourth control command Vnp for controlling the positive side arm current ip + and the negative side arm current ip ⁇ to follow each arm current command are calculated.
- the positive side arm current command ipr + and the negative side arm current command ipr ⁇ are obtained by the following equations, for example.
- ipr is an alternating current command
- idcr is a direct current command
- izpr is a circulating current command.
- ipr + (1/2) ipr + (1/3)
- idcr + izpr ipr ⁇ ⁇ (1/2) ipr + (1/3) idcr + izpr
- the command distribution unit 25a receives the calculated third control command Vpp, fourth control command Vnp, DC voltage command value Vdc, and neutral point voltage Vsn, and further, the AC voltage of each phase as a feed forward term. Vsp is input. Based on the input information, the command distribution unit 25a subtracts the voltage drop due to the inductance component in each arm 5 and 6 from the voltage shared by the positive arm 5 and the negative arm 6, respectively, by distributing the components, the positive-side arm voltage command value Vp + for positive-side arm 5 of each phase, the negative-side arm voltage command value Vp for each phase of the negative-side arm 6 - to determine that.
- phase of the voltage command generating unit 21a generates positive-side arm voltage command Vp +, the negative-side arm voltage command Vp - is positive arm current ip +, the negative-side arm current ip - to each arm current command
- the alternating current ip and the circulating current izp are controlled, and the output voltage command is used for feedforward control of the alternating voltage Vsp.
- the PWM circuit 22 performs a PWM control on each converter cell 10 in the positive arm 5 and the negative arm 6 of each phase based on the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ . Is generated.
- the voltages Vp + and Vp ⁇ are the voltage components Vp + (i) and Vp ⁇ (i) necessary for controlling the current, and the voltage component Vp + ( It can be seen that it can be decomposed into v) and Vp ⁇ (v).
- Vp + (v) and Vp ⁇ (v) for controlling the voltage are obtained from the equation (15):
- Vp + (i) and Vp ⁇ (i) for controlling the current are obtained from the equation (15):
- the voltages Vp + and Vp ⁇ represented by the equation (20) are used for the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ .
- the positive side arm voltage command Vp + and the negative side arm voltage command Vp ⁇ satisfy the expression (3), that is, from the voltages shared by the positive side arm 5 and the negative side arm 6 respectively, This is the voltage obtained by subtracting the voltage drop due to the inductance component.
- the coefficients of the third control command Vpp and the fourth control command Vnp for controlling the positive side arm current ip + and the negative side arm current ip ⁇ in Vp + and Vp ⁇ shown by the equation (20) are the interconnection transformer 13 and inductances Lac, Lc + , Lc ⁇ of the positive side reactor 9p and the negative side reactor 9n.
- the voltage components relating to AC voltage Vsp, neutral point voltage Vsn, and DC voltage command value Vdc are the same as those in the first embodiment. There is no difference between the voltages shared by these components due to inductance components.
- the voltage drop caused by the inductance component in each arm 5 and 6 is subtracted from the voltage shared by the positive side arm 5 and the negative side arm 6 of the power converter 1, respectively.
- the positive-side arm voltage command value Vp + for positive-side arm 5 of each phase the negative-side arm voltage command value Vp for each phase of the negative-side arm 6 - to determine that.
- the power The converter 1 is stably and reliably controlled.
- the alternating current ip is controlled to the alternating current command
- the circulating current ip is controlled to the circulating current command.
- Embodiment 4 FIG. Next, a power converter according to Embodiment 4 of the present invention will be described below.
- the configuration of the power converter 1 similar to that of the second embodiment shown in FIG. 6 is used, and the control according to the third embodiment shown in FIG. 7 is applied. That is, in the fourth embodiment, as shown in FIG. 6, each of the positive side arm 5 and the negative side arm 6 of each leg circuit 4 is composed of cell groups 5a, 6a in which one or more converter cells 10 are connected in series.
- the negative reactor 9n is inserted in series on the negative side of the cell group 6a only in the negative side arm 6.
- the voltages Vp + and Vp ⁇ represented by the equation (21) are used for the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ .
- the coefficients of the third control command Vpp and the fourth control command Vnp for controlling the positive side arm current ip + and the negative side arm current ip ⁇ in Vp + and Vp ⁇ shown by the equation (21) are the interconnection transformer 13 and the respective inductances Lac and Lc ⁇ of the negative reactor 9n.
- the voltage components relating to AC voltage Vsp, neutral point voltage Vsn, and DC voltage command value Vdc are the same as those in the first embodiment. There is no difference between the voltages shared by these components due to inductance components.
- the voltage drop due to the inductance component in each arm 5 and 6 is subtracted from the voltage shared by the positive side arm 5 and the negative side arm 6 of the power converter 1, respectively.
- the positive-side arm voltage command value Vp + for positive-side arm 5 of each phase the negative-side arm voltage command value Vp for each phase of the negative-side arm 6 - to determine that.
- a reactor negative reactor 9n
- the negative reactor 9n may be a small element having a low withstand voltage characteristic, and the power converter 1 has a configuration suitable for downsizing.
- the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ of the power converter 1 suitable for miniaturization are generated with high reliability, and the current control of the positive arm current ip + and the negative arm
- the power converter 1 is stably and reliably controlled without causing interference with the current control of the current ip ⁇ .
- the alternating current ip is controlled to the alternating current command
- the circulating current ip is controlled to the circulating current command.
- the voltages Vp + and Vp ⁇ represented by the equation (22) are used as the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ .
- the coefficients of the third control command Vpp and the fourth control command Vnp for controlling the positive side arm current ip + and the negative side arm current ip ⁇ in Vp + and Vp ⁇ shown by the equation (22) are the interconnection transformer 13 and the respective inductances Lac and Lc of the positive side reactor 9p and the negative side reactor 9n.
- the voltage components relating to AC voltage Vsp, neutral point voltage Vsn, and DC voltage command value Vdc are the same as those in the first embodiment. There is no difference between the voltages shared by these components due to inductance components. Thus, even when the inductances of the positive side reactor 9p and the negative side reactor 9n are equal, the same control as in the different case can be applied, and similarly stable control can be realized.
- Embodiment 6 a power converter according to Embodiment 6 of the present invention will be described below.
- the positive side arm voltage command Vp + and the negative side arm voltage command Vp ⁇ generated in the control device 20 are corrected by the modulation factor correction signal to the PWM circuit 22. input.
- the DC capacitor 34 (44) of each converter cell 10 in the positive arm 5 and the negative arm 6 varies according to the phase of the AC power supply 14. Therefore, the control device 20 generates a modulation rate correction signal based on the voltage of the DC capacitor 34 (44), and divides the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ by the modulation rate correction signal.
- the modulation factors of the positive side arm 5 and the negative side arm 6 determined by the positive side arm voltage command Vp + and the negative side arm voltage command Vp ⁇ are corrected according to the phase of the AC power source 14 to improve controllability. To do.
- the modulation factor correction signal may be, for example, the average voltage of the DC capacitors 34 (44) of all the converter cells 10 in the positive side arm 5 and the negative side arm 6, or the DC of the converter cell 10 for each arm.
- the average voltage of the capacitor 34 (44) may be used.
- the positive arm voltage command Vp + and the negative arm voltage command Vp ⁇ are derived for each converter cell 10, and the voltage of the DC capacitor 34 (44) for each converter cell 10 is used as the modulation factor correction signal. May be.
- control device 20 performs control to feed forward the AC voltage Vsp by connecting the AC side of the power converter 1 to the grid.
- the AC side is connected to another AC circuit, there is no need for feedforward control of the AC voltage Vsp.
- the present invention can be freely combined with each other, or can be modified or omitted as appropriate.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
- Rectifiers (AREA)
Abstract
Description
変換器を多重化する方法の1つとして、複数の変換器の出力をカスケード接続したマルチレベル変換器があり、その中の一つにモジュラーマルチレベル変換器がある。モジュラーマルチレベル変換器の各アームは、複数の変換器セルがカスケード接続されて構成されている。
また、従来のモジュラーマルチレベル変換器の各相の制御は、コンデンサ電圧指令値に全ての直流コンデンサの電圧値の平均値を追従させる平均値制御と、コンデンサ電圧指令値に各直流コンデンサの電圧値をそれぞれ追従させる個別バランス制御と、さらに第1アーム内の全ての直流コンデンサの電圧値の平均値と第2アーム内の全ての直流コンデンサの電圧値の平均値とを一致させるアームバランス制御とを備える。そして、モジュラーマルチレベル変換器外には流出しないでモジュラーマルチレベル変換器内で循環する循環電流を制御し、また各相の交流電流を制御するように電圧指令値が演算される(例えば、特許文献1、非特許文献1参照)。
以下、この発明の実施の形態1による電力変換装置を図に基づいて以下に説明する。図1は、この発明の実施の形態1による電力変換装置の概略構成図である。
図1に示すように、電力変換装置は主回路である電力変換器1と、電力変換器1を制御する制御装置20とを備える。電力変換器1は、複数相交流この場合三相交流と直流との間で電力変換を行うもので、交流側は連系変圧器13を介して交流回路としての系統である交流電源14に接続され、直流側はインピーダンス15を介して直流電源16に接続される。
なお、連系変圧器13の代わりに連系リアクトルを介して交流電源14に接続しても良い。また、電力変換器1の直流側は、直流負荷に接続されてもよいし、直流出力を行う他の電力変換装置に接続されても良い。
各レグ回路4の正側アーム5、負側アーム6のそれぞれは、1以上の変換器セル10を直列接続したセル群5a、6aで構成され、正側リアクトル9p、負側リアクトル9nがそれぞれ直列に挿入される。この場合、正側リアクトル9p、負側リアクトル9nは交流端7側に接続され、正側リアクトル9pおよび負側リアクトル9nで、3端子のリアクトル8を構成している。
なお、正側リアクトル9p、負側リアクトル9nが挿入される位置は、各アーム5、6内のいずれの位置でも良く、それぞれ複数個であっても良い。
各相の正側アーム5、負側アーム6にそれぞれ流れる正側アーム電流ip+、負側アーム電流ip-、各相交流線に流れる交流電流ipは、それぞれ図示しない電流検出器により検出されて制御装置20に入力される。さらに、図示しない電圧検出器により検出される交流電源14の各相電圧(以下、交流電圧Vspと称す)、電力変換器1の中性点電圧Vsn、直流母線間電圧である直流電源16の電圧の指令値(以下、直流電圧指令値Vdc)が制御装置20に入力される。なお、各相の交流電流ipは、各相の正側アーム5、負側アーム6にそれぞれ流れる正側アーム電流ip+、負側アーム電流ip-とから演算して用いても良い。
なお、制御装置20の構成および動作の詳細は後述する。
図2の変換器セル10は、それぞれダイオード31が逆並列に接続された複数(この場合2個)の半導体スイッチング素子30(以下、単にスイッチング素子と称す)の直列体32と、この直列体32に並列接続され直流電圧を平滑化する直流コンデンサ34とから構成される。スイッチング素子30は、IGBT(Insulated Gate Bipolar Transistor)やGCT(Gate Commutated Turn-off thyristor)等の自己消弧型のスイッチング素子から成り、それぞれダイオード31が逆並列に接続されたスイッチ33P、33Nが用いられる。
そして、図2に示すように、変換器セル10は、スイッチ33Nのスイッチング素子30の両端子を出力端とし、スイッチング素子30をオン・オフさせることにより、この出力端から、直流コンデンサ34の両端電圧およびゼロ電圧を出力する。
図3の変換器セル10は、2つの直列体42を並列接続し、さらに直列体42に並列接続され直流電圧を平滑化する直流コンデンサ44を備えて構成される。各直列体42は、それぞれダイオード41が逆並列に接続された複数(この場合2個)のスイッチング素子40を直列接続して構成される。スイッチング素子40は、IGBTやGCT等の自己消弧型のスイッチング素子から成り、それぞれダイオード41が逆並列に接続されて構成されるスイッチ43P、43Nが用いられる。
そして、図3に示すように、変換器セル10は、それぞれの直列体42の中間接続点となるスイッチング素子40の端子を出力端とし、スイッチング素子40をオン・オフさせることにより、この出力端から、直流コンデンサ44両端の正電圧、負電圧およびゼロ電圧を出力する。
電力変換器1は直流および交流を出力するため、直流側と交流側の両側の制御が必要となる。さらに、交流側出力にも直流側出力にも寄与しないで正側、負側のアーム間を還流する循環電流izpが電力変換器1内を流れるため、直流側制御、交流側制御に加え循環電流izpの制御が必要となる。また、この場合、交流端7が系統の交流電源14に連系されているため、交流側制御に必要な交流電圧を電力変換器1から出力する必要があり、交流連系点の交流電圧Vspをフィードフォワードすることにより補償する制御を構成する。
図4は、制御装置20の構成例を示すブロック図である。
制御装置20は、上述したように電圧指令生成部21とPWM回路22とを備える。電圧指令生成部21は、交流電流ipを制御するための交流電流制御部23と、電力変換器1内で循環する各相の循環電流izpを制御するための循環電流制御部24とを電流制御部として備え、さらに各相の正側アーム電圧指令Vp+と負側アーム電圧指令Vp-とを決定する指令分配部25を備える。
循環電流制御部24は、各相の循環電流izpと設定された循環電流指令、例えば0との偏差が0になるように電圧指令である第2制御指令Vzpを演算する。即ち、各相の循環電流izpを循環電流指令に追従制御するための第2制御指令Vzpを演算する。各相の循環電流izpは、各相の正側アーム5、負側アーム6にそれぞれ流れる正側アーム電流ip+、負側アーム電流ip-とから演算できる。
なお、電力変換器1と交流電源14とが絶縁されていない場合は、交流電圧Vspと直流電源16の電圧とにより中性点電圧Vsnが演算される。
そして指令分配部25は、これら入力情報に基づいて、正側アーム5、負側アーム6がそれぞれ出力分担する電圧から、各アーム5、6内のインダクタンス成分による電圧降下分をそれぞれ差し引いて、電圧成分を分配することにより、各相の正側アーム5に対する正側アーム電圧指令Vp+と、各相の負側アーム6に対する負側アーム電圧指令Vp-とを決定する。
PWM回路22は、正側アーム電圧指令Vp+、負側アーム電圧指令Vp-に基づいて、各相の正側アーム5、負側アーム6内の各変換器セル10をPWM制御するゲート信号22aを生成する。
生成されたゲート信号22aにより各変換器セル10内のスイッチング素子30(40)が駆動制御され、電力変換器1の出力電圧は所望の値に制御される。
図5は、電力変換器1の1相分における各部の電圧、電流を回路上で示す図である。
ここで、Lacは連系変圧器13のインダクタンス、Lc+は正側リアクトル9pのインダクタンス、Lc-は負側リアクトル9nのインダクタンスを示す。
正側アーム電圧指令Vp+は、正側アーム5内の変換器セル10を直列接続したセル群5aが出力する電圧の指令値であり、負側アーム電圧指令Vp-は、負側アーム6内の変換器セル10を直列接続したセル群6aが出力する電圧の指令値である。この場合、セル群5a、6aの出力電圧が、Vp+、Vp-に制御されているものとする。
また、直流電源16の電圧も直流電圧指令値Vdcに制御されているとする。
ip=ip+-ip-
また、循環電流izpは以下のように定義される。
izp=(ip++ip-)/2
すると、正側アーム電流ip+、負側アーム電流ip-は、以下の式(1)、式(2)で表される。
交流電流ipと循環電流izpとの非干渉化のために、式(5)を対角化すると、以下の式(6)が得られる。
電圧を制御するためのVp+(v)、Vp-(v)は、式(5)より、
また、電流を制御するためのVp+(i)、Vp-(i)は、式(6)より、
交流電流ipを交流電流指令に追従制御するための第1制御指令Vcpと、循環電流izpを循環電流指令に追従制御するための第2制御指令Vzpとが非干渉化され、交流電流制御と循環電流制御とをそれぞれ独立に行うためには、第1制御指令Vcp、第2制御指令Vzpは、式(8)から、以下の式(9)の形となれば良い。
交流電流制御の制御対象は、Lac+Lc+・Lc-/(Lc++Lc-)
循環電流制御の制御対象は、Lc++Lc-
である。
交流電流制御については、交流端7よりも交流電源14側のインダクタンスLacのみでなく、正側アーム5、負側アーム6の並列インダクタンス成分(Lc+・Lc-/(Lc++Lc-))も制御対象である。即ち第1制御指令Vcpでは、並列インダクタンス成分による電圧降下分は考慮されていない。
この正側アーム電圧指令Vp+、負側アーム電圧指令Vp-は式(3)を満たし、即ち、正側アーム5、負側アーム6がそれぞれ出力分担する電圧から、各アーム5、6内のインダクタンス成分による電圧降下分をそれぞれ差し引いた電圧である。なお、電圧降下分を考慮するインダクタンス成分とは、各アーム5、6の並列インダクタンス成分を除いたものである。
交流電流ipは正側アーム5、負側アーム6をそれぞれ逆方向に流れるため、第1制御指令Vcpに係る電圧成分は、正側アーム5と負側アーム6とで逆極性となる。
循環電流izpは正側アーム5、負側アーム6をそれぞれ同方向に流れるため、第2制御指令Vzpに係る電圧成分は、正側アーム5と負側アーム6とで同極性となる。
直流電圧指令値Vdcに係る電圧成分は、正側アーム5に対する電圧のみで係数は1である。
次に、この発明の実施の形態2による電力変換装置を図6に基づいて以下に説明する。図6は、この発明の実施の形態2による電力変換装置の概略構成図である。
この実施の形態2では、各レグ回路4の正側アーム5、負側アーム6のそれぞれは、1以上の変換器セル10を直列接続したセル群5a、6aで構成され、負側アーム6のみに、セル群6aの負極側に負側リアクトル9nが直列に挿入される。この他の構成は、図1で示した上記実施の形態1と同様である。
なお、図6では便宜上、制御装置20の図示を省略した。
インダクタンスLc+を0として、上記実施の形態1での式(12)を変形すると、以下の式(13)が得られる。
式(13)で示されるVp+、Vp-において、交流電流ipを制御する第1制御指令Vcpに係る電圧成分は、第1制御指令Vcpに係数を乗算した電圧である。交流電流ipは正側アーム5、負側アーム6をそれぞれ逆方向に流れ、正側アーム電圧指令Vp+に対して、第1制御指令Vcpに負極性の係数が用いられ、負側アーム電圧指令Vp-に対して、第1制御指令Vcpに正極性の係数が用いられる。この場合、正側リアクトルが存在しないので正側アーム5に対する係数の大きさは1となる。負側アーム6に対する係数は、連系変圧器13および負側リアクトル9nの各インダクタンスLac、Lc-から求められる。
交流電圧Vsp、中性点電圧Vsnおよび直流電圧指令値Vdcに係る電圧成分については、上記実施の形態1と同様である。これらが分担する電圧については、インダクタンス成分による差異はない。
また、電力変換器1の各相のレグ回路4において、負側アーム6のセル群6aの負極側のみにリアクトル(負側リアクトル9n)が挿入される。このため負側リアクトル9nは、耐電圧特性が低い小型の素子で良く、電力変換器1は小型化に適した構成となる。
このように、小型化に適した電力変換器1の正側アーム電圧指令Vp+と負側アーム電圧指令Vp-とが信頼性良く生成され、交流電流ipの電流制御と循環電流izpの電流制御との間で干渉が生じることなく、電力変換器1は安定して信頼性良く制御される。
次に、この発明の実施の形態2による電力変換装置を図7に基づいて以下に説明する。この実施の形態3では、図1で示した上記実施の形態1と同様の電力変換器1を用い、制御装置20内の電圧指令生成部の構成が上記実施の形態1と異なる。図7は、この実施の形態3による制御装置20の構成例を示すブロック図である。
制御装置20は、正側アーム電圧指令Vp+と負側アーム電圧指令Vp-とを生成する電圧指令生成部21aと、PWM回路22とを備えてゲート信号22aを生成し、各相の正側アーム5、負側アーム6内の各変換器セル10を制御する。
各相の正側アーム5、負側アーム6にそれぞれ流れる正側アーム電流ip+、負側アーム電流ip-、さらに、交流電源14の各相電圧である交流電圧Vsp、電力変換器1の中性点電圧Vsn、直流電圧指令値Vdcが制御装置20の電圧指令生成部21aに入力される。
アーム電流制御部26は、検出された正側アーム電流ip+、負側アーム電流ip-と設定された各アーム電流指令との偏差がそれぞれ0になるように電圧指令である第3制御指令Vpp、第4制御指令Vnpを演算する。即ち、正側アーム電流ip+、負側アーム電流ip-を各アーム電流指令に追従制御するための第3制御指令Vpp、第4制御指令Vnpを演算する。
ipr+=(1/2)ipr+(1/3)idcr+izpr
ipr-=-(1/2)ipr+(1/3)idcr+izpr
PWM回路22は、正側アーム電圧指令Vp+、負側アーム電圧指令Vp-に基づいて、各相の正側アーム5、負側アーム6内の各変換器セル10をPWM制御するゲート信号22aを生成する。
電力変換器1の1相分における各部の電圧、電流の関係は、上記実施の形態1の図5で示したものと同様で、上記式(1)~式(4)が成立する。
交流電流ipと、正側アーム電流ip+、負側アーム電流ip-との関係式である、
ip=ip+-ip-
と、式(3)、式(4)より、ipを消去して電流の時間微分について整理すると、
正側アーム電流ip+と負側アーム電流ip-との非干渉化のために、式(14)を対角化すると、以下の式(15)が得られる。
電圧を制御するためのVp+(v)、Vp-(v)は、式(15)より、
また、電流を制御するためのVp+(i)、Vp-(i)は、式(15)より、
式(17)に基づいて、正側アーム電流ip+を正側アーム電流指令に追従制御するための第3制御指令Vpp、負側アーム電流ip-を負側アーム電流指令に追従制御するための第4制御指令Vnpは、以下の式(18)で示される。
この正側アーム電圧指令Vp+、負側アーム電圧指令Vp-は式(3)を満たし、即ち、正側アーム5、負側アーム6がそれぞれ出力分担する電圧から、各アーム5、6内のインダクタンス成分による電圧降下分をそれぞれ差し引いた電圧である。
式(20)で示されるVp+、Vp-において、正側アーム電流ip+、負側アーム電流ip-をそれぞれ制御する第3制御指令Vpp、第4制御指令Vnpの係数は、連系変圧器13および正側リアクトル9p、負側リアクトル9nの各インダクタンスLac、Lc+、Lc-から求められる。
交流電圧Vsp、中性点電圧Vsnおよび直流電圧指令値Vdcに係る電圧成分については、上記実施の形態1と同様である。これらが分担する電圧については、インダクタンス成分による差異はない。
次に、この発明の実施の形態4による電力変換装置を以下に説明する。この実施の形態では、図6で示した上記実施の形態2と同様の電力変換器1の構成を用い、図7で示した上記実施の形態3による制御を適用したものである。
即ち、この実施の形態4では、図6に示すように、各レグ回路4の正側アーム5、負側アーム6のそれぞれは、1以上の変換器セル10を直列接続したセル群5a、6aで構成され、負側アーム6のみに、セル群6aの負極側に負側リアクトル9nが直列に挿入される。そして、上記実施の形態3と同様の制御装置20を用いるが、この場合、正側リアクトル9pが無いので、指令分配部25aでの演算が異なり、以下に示す。
インダクタンスLc+を0として、上記実施の形態3での式(20)を変形すると、以下の式(21)が得られる。
式(21)で示されるVp+、Vp-において、正側アーム電流ip+、負側アーム電流ip-をそれぞれ制御する第3制御指令Vpp、第4制御指令Vnpの係数は、連系変圧器13および負側リアクトル9nの各インダクタンスLac、Lc-から求められる。
交流電圧Vsp、中性点電圧Vsnおよび直流電圧指令値Vdcに係る電圧成分については、上記実施の形態1と同様である。これらが分担する電圧については、インダクタンス成分による差異はない。
また、電力変換器1の各相のレグ回路4において、負側アーム6のセル群6aの負極側のみにリアクトル(負側リアクトル9n)が挿入される。このため負側リアクトル9nは、耐電圧特性が低い小型の素子で良く、電力変換器1は小型化に適した構成となる。
このように、小型化に適した電力変換器1の正側アーム電圧指令Vp+と負側アーム電圧指令Vp-とが信頼性良く生成され、正側アーム電流ip+の電流制御と負側アーム電流ip-の電流制御との間で干渉が生じることなく、電力変換器1は安定して信頼性良く制御される。また、正側アーム電流ip+、負側アーム電流ip-をそれぞれ制御することにより、交流電流ipは交流電流指令に制御され、循環電流ipは循環電流指令に制御される。
次に、この発明の実施の形態4による電力変換装置を以下に説明する。この実施の形態では、上記実施の形態3において、正側リアクトル9pのインダクタンスLc+と負側リアクトル9nのインダクタンスLc-とが等しい場合を示す。
即ち、この実施の形態5では、図1に示すように、各レグ回路4の正側アーム5、負側アーム6のそれぞれは、1以上の変換器セル10を直列接続したセル群5a、6aで構成され、正側アーム5、負側アーム6に、それぞれ正側リアクトル9p、負側リアクトル9nが直列に挿入される。そして、上記実施の形態3と同様の制御装置20において、指令分配部25aでの演算は以下のようになる。
Lc+=Lc-=Lcとして、上記実施の形態3での式(20)を変形すると、以下の式(22)が得られる。
式(22)で示されるVp+、Vp-において、正側アーム電流ip+、負側アーム電流ip-をそれぞれ制御する第3制御指令Vpp、第4制御指令Vnpの係数は、連系変圧器13および正側リアクトル9p、負側リアクトル9nの各インダクタンスLac、Lcから求められる。
交流電圧Vsp、中性点電圧Vsnおよび直流電圧指令値Vdcに係る電圧成分については、上記実施の形態1と同様である。これらが分担する電圧については、インダクタンス成分による差異はない。
このように、正側リアクトル9p、負側リアクトル9nのインダクタンスが等しい場合にも、異なる場合と同様の制御が適用でき、同様に安定した制御が実現できる。
次に、この発明の実施の形態6による電力変換装置を以下に説明する。
この実施の形態では、図8に示すように、制御装置20内で生成される正側アーム電圧指令Vp+、負側アーム電圧指令Vp-を、変調率補正信号により補正してPWM回路22に入力する。
正側アーム5、負側アーム6内の各変換器セル10の直流コンデンサ34(44)は、交流電源14の位相に応じて変動する。このため、制御装置20は、直流コンデンサ34(44)の電圧に基づく変調率補正信号を生成して、正側アーム電圧指令Vp+、負側アーム電圧指令Vp-を変調率補正信号により除して用いる。これにより正側アーム電圧指令Vp+、負側アーム電圧指令Vp-にて決定される正側アーム5、負側アーム6の各変調率は交流電源14の位相に応じて補正され制御性が向上する。
また、正側アーム電圧指令Vp+、負側アーム電圧指令Vp-を各変換器セル10毎に導出し、各変換器セル10毎の直流コンデンサ34(44)の電圧を変調率補正信号に用いてもよい。
Claims (11)
- それぞれ正側アームと負側アームとが直列接続されその接続点が各相交流線に接続される複数のレグ回路を正負の直流母線間に並列接続して備え、複数相交流と直流との間で電力変換を行う電力変換器と、
該電力変換器を制御する制御装置とを備えた電力変換装置において、
上記各レグ回路の上記正側アーム、上記負側アームのそれぞれは、互いに直列接続された複数の半導体スイッチング素子の直列体とこの直列体に並列接続された直流コンデンサとから成り上記半導体スイッチング素子の端子を出力端とする変換器セルを、1あるいは複数直列接続して構成され、
上記制御装置は、上記正側アームに対する第1電圧指令と上記負側アームに対する第2電圧指令とを生成する電圧指令生成部を有して、上記正側アーム、上記負側アーム内の上記各変換器セルを出力制御し、
上記電圧指令生成部は、
上記各相交流線に流れる交流電流成分および上記各レグ回路間で循環する各相の循環電流成分を制御する制御指令を演算する電流制御部と、
上記制御指令と上記直流母線間の電圧の直流電圧指令値とに基づいて、上記正側アーム、上記負側アームがそれぞれ出力分担する電圧から該正側アーム内、該負側アーム内の各インダクタンス成分による電圧降下分をそれぞれ差し引いて上記第1電圧指令、上記第2電圧指令を決定する指令分配部とを備えた
電力変換装置。 - 上記各相交流線が交流回路に接続され、上記電圧指令生成部は、上記交流回路の各相電圧をフィードフォワード項に用いて上記正側アームに対する第1電圧指令と上記負側アームに対する第2電圧指令とを生成する請求項1に記載の電力変換装置。
- 上記電流制御部が演算する上記制御指令は、上記各相交流線に流れる交流電流が交流電流指令に近づくように演算された第1制御指令と、上記各レグ回路間で循環する各相の循環電流が循環電流指令に近づくように演算された第2制御指令とである請求項1または請求項2に記載の電力変換装置。
- 上記電流制御部が演算する上記制御指令は、上記各レグ回路の上記正側アーム、上記負側アームをそれぞれ流れる各アーム電流が、設定された各電流指令に近づくように演算された第3制御指令と第4制御指令とであり、上記電流制御部は、上記各アーム電流を制御することにより、上記交流電流成分および上記循環電流成分を制御する請求項1または請求項2に記載の電力変換装置。
- 上記各レグ回路の上記正側アーム、上記負側アームの少なくとも一方に、リアクトルが直列に挿入されている請求項1または請求項2に記載の電力変換装置。
- 上記指令分配部は、挿入された上記リアクトルのインダクタンスを上記インダクタンス成分として、上記第1電圧指令、上記第2電圧指令の演算に用いる請求項5に記載の電力変換装置。
- 上記各レグ回路の上記負側アームのみに上記リアクトルが直列に挿入されている請求項5に記載の電力変換装置。
- 上記リアクトルは、上記負側アーム内の上記変換器セルの負極側に挿入される請求項7に記載の電力変換装置。
- 上記各レグ回路の上記正側アーム、上記負側アームの双方に、等しいインダクタンスを有する上記リアクトルが直列に挿入されている請求項5に記載の電力変換装置。
- 上記電圧指令生成部は、上記変換器セル内の上記直流コンデンサの電圧に基づいて変調率補正信号を生成し、上記指令分配部からの上記第1電圧指令、上記第2電圧指令を上記変調率補正信号で除算して補正する請求項1または請求項2に記載の電力変換装置。
- 上記電圧降下分は、上記正側アーム、上記負側アームによる並列インダクタンス成分を除いたインダクタンス成分によるものである請求項1または請求項2に記載の電力変換装置。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015556733A JP6188827B2 (ja) | 2014-01-09 | 2014-12-03 | 電力変換装置 |
EP14877686.7A EP3093975B1 (en) | 2014-01-09 | 2014-12-03 | Power conversion system |
US15/109,594 US9812992B2 (en) | 2014-01-09 | 2014-12-03 | Power conversion system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014-002069 | 2014-01-09 | ||
JP2014002069 | 2014-01-09 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2015104922A1 true WO2015104922A1 (ja) | 2015-07-16 |
Family
ID=53523760
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2014/081951 WO2015104922A1 (ja) | 2014-01-09 | 2014-12-03 | 電力変換装置 |
Country Status (4)
Country | Link |
---|---|
US (1) | US9812992B2 (ja) |
EP (1) | EP3093975B1 (ja) |
JP (1) | JP6188827B2 (ja) |
WO (1) | WO2015104922A1 (ja) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9755542B2 (en) | 2014-05-21 | 2017-09-05 | Mitsubishi Electric Corporation | Direct-current power transmission power conversion device and direct-current power transmission power conversion method |
US9806630B2 (en) | 2014-08-01 | 2017-10-31 | Mitsubishi Electric Corporation | Power conversion device |
US9960709B2 (en) | 2015-03-17 | 2018-05-01 | Mitsubishi Electric Corporation | Power conversion device |
WO2022259465A1 (ja) | 2021-06-10 | 2022-12-15 | 三菱電機株式会社 | 電力変換装置 |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3093975B1 (en) * | 2014-01-09 | 2022-09-28 | Mitsubishi Electric Corporation | Power conversion system |
JP6522140B2 (ja) * | 2015-09-17 | 2019-05-29 | 三菱電機株式会社 | 電力変換装置 |
EP3352361B1 (en) * | 2015-09-17 | 2019-11-27 | Mitsubishi Electric Corporation | Power conversion device |
JP6509352B2 (ja) * | 2015-09-17 | 2019-05-08 | 三菱電機株式会社 | 電力変換装置 |
WO2017168518A1 (ja) * | 2016-03-28 | 2017-10-05 | 三菱電機株式会社 | 電力変換装置 |
WO2018158935A1 (ja) * | 2017-03-03 | 2018-09-07 | 三菱電機株式会社 | 電力変換装置、および通信方法 |
EP4120543A4 (en) * | 2020-03-11 | 2023-04-19 | Mitsubishi Electric Corporation | POWER CONVERSION DEVICE |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011078213A (ja) * | 2009-09-30 | 2011-04-14 | Tokyo Institute Of Technology | モータ始動方法 |
JP2011182517A (ja) | 2010-02-26 | 2011-09-15 | Tokyo Institute Of Technology | 電力変換器 |
JP2011193615A (ja) * | 2010-03-15 | 2011-09-29 | Hitachi Ltd | 電力変換装置 |
JP2013027260A (ja) * | 2011-07-26 | 2013-02-04 | Hitachi Ltd | 電力変換装置 |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0710165B2 (ja) * | 1989-07-31 | 1995-02-01 | 株式会社日立製作所 | 電力変換装置及びスナバ回路 |
JP2656684B2 (ja) * | 1991-06-12 | 1997-09-24 | 三菱電機株式会社 | エレベータの停電時運転装置 |
JPH05316734A (ja) * | 1992-05-13 | 1993-11-26 | Fuji Electric Co Ltd | 直流電源装置 |
JP3591548B2 (ja) * | 1995-11-07 | 2004-11-24 | 株式会社安川電機 | 多重整流回路 |
US7972031B2 (en) * | 2007-05-31 | 2011-07-05 | Nthdegree Technologies Worldwide Inc | Addressable or static light emitting or electronic apparatus |
WO2010082265A1 (ja) * | 2009-01-13 | 2010-07-22 | 三菱電機株式会社 | 電力変換装置 |
KR101374982B1 (ko) * | 2009-06-04 | 2014-03-14 | 다이킨 고교 가부시키가이샤 | 전력 변환 장치 |
JP5872480B2 (ja) | 2009-12-01 | 2016-03-01 | アーベーベー・シュバイツ・アーゲー | コンバータ回路を作動するための方法、およびこの方法を実行するための装置 |
JP5721096B2 (ja) | 2010-08-23 | 2015-05-20 | 国立大学法人東京工業大学 | 電力変換器 |
JP5825902B2 (ja) | 2011-07-25 | 2015-12-02 | 株式会社日立製作所 | 電力変換装置 |
JP6091781B2 (ja) | 2012-07-11 | 2017-03-08 | 株式会社東芝 | 半導体電力変換装置 |
US9564827B2 (en) * | 2013-04-02 | 2017-02-07 | Mitsubishi Electric Corporation | Power conversion device |
JP6147363B2 (ja) * | 2014-01-06 | 2017-06-14 | 三菱電機株式会社 | 電力変換装置 |
EP3093975B1 (en) * | 2014-01-09 | 2022-09-28 | Mitsubishi Electric Corporation | Power conversion system |
EP3148067B1 (en) * | 2014-05-21 | 2020-10-07 | Mitsubishi Electric Corporation | Direct-current power transmission power conversion device and direct-current power transmission power conversion method |
-
2014
- 2014-12-03 EP EP14877686.7A patent/EP3093975B1/en active Active
- 2014-12-03 JP JP2015556733A patent/JP6188827B2/ja active Active
- 2014-12-03 US US15/109,594 patent/US9812992B2/en active Active
- 2014-12-03 WO PCT/JP2014/081951 patent/WO2015104922A1/ja active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011078213A (ja) * | 2009-09-30 | 2011-04-14 | Tokyo Institute Of Technology | モータ始動方法 |
JP2011182517A (ja) | 2010-02-26 | 2011-09-15 | Tokyo Institute Of Technology | 電力変換器 |
JP2011193615A (ja) * | 2010-03-15 | 2011-09-29 | Hitachi Ltd | 電力変換装置 |
JP2013027260A (ja) * | 2011-07-26 | 2013-02-04 | Hitachi Ltd | 電力変換装置 |
Non-Patent Citations (2)
Title |
---|
IEEJ TRANSACTIONS D (ON INDUSTRY APPLICATIONS, vol. 131, no. 1, 2011, pages 84 - 92 |
See also references of EP3093975A4 |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9755542B2 (en) | 2014-05-21 | 2017-09-05 | Mitsubishi Electric Corporation | Direct-current power transmission power conversion device and direct-current power transmission power conversion method |
US9806630B2 (en) | 2014-08-01 | 2017-10-31 | Mitsubishi Electric Corporation | Power conversion device |
US9960709B2 (en) | 2015-03-17 | 2018-05-01 | Mitsubishi Electric Corporation | Power conversion device |
WO2022259465A1 (ja) | 2021-06-10 | 2022-12-15 | 三菱電機株式会社 | 電力変換装置 |
Also Published As
Publication number | Publication date |
---|---|
US20160329831A1 (en) | 2016-11-10 |
EP3093975B1 (en) | 2022-09-28 |
EP3093975A1 (en) | 2016-11-16 |
US9812992B2 (en) | 2017-11-07 |
JP6188827B2 (ja) | 2017-08-30 |
EP3093975A4 (en) | 2017-08-09 |
JPWO2015104922A1 (ja) | 2017-03-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6188827B2 (ja) | 電力変換装置 | |
JP6180641B2 (ja) | 電力変換装置 | |
JP6207730B2 (ja) | 直流送電電力変換装置および直流送電電力変換方法 | |
US9960709B2 (en) | Power conversion device | |
JP6509352B2 (ja) | 電力変換装置 | |
JP6522141B2 (ja) | 電力変換装置 | |
US8649196B2 (en) | Power converting apparatus with an output voltage that is the sum of voltages generated by individual inverters | |
JP6522140B2 (ja) | 電力変換装置 | |
US11936306B2 (en) | Power conversion device | |
WO2016031430A1 (ja) | 電力変換装置 | |
JP4878645B2 (ja) | 電力変換装置 | |
JP6771707B1 (ja) | 電力変換装置 | |
JP7367261B1 (ja) | 電力変換システムおよび制御装置 | |
JP7216411B2 (ja) | 電力変換システム、発電システム、有効電力授受システム及び電力系統 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 14877686 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2015556733 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15109594 Country of ref document: US |
|
REEP | Request for entry into the european phase |
Ref document number: 2014877686 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2014877686 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |