CN109905019B - Discharge circuit with protection function and control method thereof - Google Patents
Discharge circuit with protection function and control method thereof Download PDFInfo
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- CN109905019B CN109905019B CN201910186215.XA CN201910186215A CN109905019B CN 109905019 B CN109905019 B CN 109905019B CN 201910186215 A CN201910186215 A CN 201910186215A CN 109905019 B CN109905019 B CN 109905019B
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Abstract
The invention relates to a discharge circuit with a protection function and a control method thereof, wherein the discharge circuit comprises a bus support capacitor and an active discharge circuit; the active discharge circuit includes: the power circuit comprises a power resistor, a first switch, a first control circuit and a second control circuit; the power resistor is connected with the first switch in series and then coupled between the direct current input positive end and the direct current input negative end, and the power resistor, the first switch and the bus support capacitor form an active discharge main loop; the first control circuit is configured to provide at least a first control signal to control the first switch to be turned on and off; the second control circuit provides at least a second control signal to control the operation of the first control circuit during normal operation, and the first control circuit is further configured to cause the active discharge primary circuit to actively open when the second control circuit is abnormal. The technical scheme provided by the embodiment of the invention has flexible control mode, and can effectively avoid the damage of the power resistor Rp and the system caused by the continuous abnormal voltage of the bus supporting capacitor Cp.
Description
Technical Field
The invention belongs to the technical field of electronic circuits, and particularly relates to a discharge circuit with a protection function and a control method thereof.
Background
The power of the electric automobile comes from the battery, the driving motor controller converts the direct current of the battery into alternating current through inversion so as to drive the motor to output torque, and the torque is transmitted to the wheels through the transmission system so as to drive the automobile to run. In order to stabilize the fluctuation of the bus voltage at the input end of the driving motor controller, optimize the response time of current output and absorb the peak voltage of the power module generated by the chopping of the high-speed switch, a capacitor (generally hundreds to thousands of microfarads) is usually connected in parallel with the dc input end of the driving motor controller, and the capacitor is defined as a bus supporting capacitor, and is denoted by Cp.
Because the bus supporting capacitor Cp is used as an energy storage element and has higher voltage, when the driving motor controller stops working, after the power battery cuts off a path for transmitting energy, the driving motor controller needs to have active discharge and passive discharge functions so as to ensure that the voltage of the bus supporting capacitor Cp is reduced to a safe voltage threshold value within a specified time, and avoid the injury to personnel caused by various system faults or misoperation and other problems. Generally, a passive discharge method is to connect a resistor directly in parallel at two ends of a dc bus (BAT + and BAT-) at two ends of the dc bus are defined herein to realize discharge of a bus support capacitor Cp. Therefore, the active discharge is used to solve the problem of the discharge time of the bus bar support capacitor Cp, and the time required for the passive discharge is rapidly reduced from 5min to 3s or shorter. Fig. 1 shows a schematic diagram of a main current circuit of the current active discharging scheme, as shown in the figure, a switch K is closed, and energy on a bus supporting capacitor Cp is rapidly consumed through a high-power active discharging resistor Rp, so that the voltage of the bus supporting capacitor Cp is rapidly reduced to a safe level. In some cases, if the energy of the bus support capacitor Cp is continuously provided by the power battery (the drive motor controller has not disconnected the energy transmission loop from the power battery) or the drive motor generates power at a high speed (high-speed trailer, rollover, etc.) and feeds the power battery to the bus support capacitor Cp or the vehicle is in a charging state (the bus support capacitor Cp continuously has a high voltage and the MCU does not operate), the high-power active discharge resistor Rp continuously converts the energy of the bus support capacitor Cp into heat, the temperature of the high-power active discharge resistor Rp rises continuously, the high-power active discharge resistor Rp reaches a limit in a short time (tens of seconds or even several seconds) and is burnt out, the drive motor controller of a lighter is damaged and fails, and a fire disaster is caused.
Disclosure of Invention
In order to solve the technical problem that the active discharge resistor or the system is damaged due to continuous abnormal voltage of the bus support capacitor, the embodiment of the invention provides a discharge circuit with a protection function and a control method thereof.
In a first aspect of the present invention, a discharge circuit with a protection function provided in an embodiment of the present invention includes a bus support capacitor and an active discharge circuit;
the bus bar support capacitor comprises a first conductive terminal coupled to the positive end of the direct current input and a second conductive terminal coupled to the negative end of the direct current input;
the active discharge circuit includes: the power circuit comprises a power resistor, a first switch, a first control circuit and a second control circuit;
the power resistor is connected with the first switch in series and then coupled between the direct current input positive end and the direct current input negative end, and the power resistor, the first switch and the bus support capacitor form an active discharge main loop;
the first control circuit comprises a first conductive terminal coupled to the voltage source node, a second conductive terminal coupled to the negative terminal of the direct current input, an output terminal providing a first control signal to the first switch, and an input terminal coupled to receive a second control signal, the first control circuit is configured to provide at least the first control signal to control the first switch to be turned on and off;
the second control circuit comprises an output end coupled to the input end of the first control circuit to provide a second control signal for the first control circuit, and the second control circuit is configured to provide at least the second control signal to control the working state of the first control circuit when the second control circuit works normally; the first control circuit is further configured to force the active discharge primary circuit to operate when the second control circuit is abnormal and to cause the active discharge primary circuit to be actively disconnected after a set time has elapsed.
In some embodiments, the first control circuit comprises a second switch, the output of the second control circuit providing a second control signal to the second switch, the on and off portion of the second switch being controlled by the second control signal, the on and off of the second switch being synchronized with the on and off action of the first switch.
In some embodiments, the second control circuit includes a reset control module configured to actively reset the state of the discharge circuit when the second control circuit is operating normally.
In some embodiments, the discharge circuit further comprises a passive discharge circuit;
the passive discharge circuit comprises a passive discharge module and a voltage stabilizing circuit;
the passive discharge module comprises a first conductive terminal coupled to the positive end of the direct current input and a second conductive terminal coupled to provide an electric connection, and is configured to passively discharge the bus supporting capacitor Cp;
the voltage stabilizing circuit comprises an input end coupled to the second conductive terminal of the passive discharge module, an output end coupled to the negative end of the direct current input, and a voltage source node coupled to provide a voltage source, and is configured to provide a stable voltage source.
In certain embodiments, the first control circuit comprises a control module and a timing module;
the control module comprises a first conductive terminal coupled to the voltage source node, a connection terminal coupled to provide an electrical connection, a control terminal coupled to the first switch, and a second conductive terminal coupled to the negative terminal of the DC input;
the timing module comprises a first conductive terminal coupled to the voltage source node, a second conductive terminal coupled to the DC input negative terminal and a third conductive terminal coupled to the connection terminal of the control module, and is configured to time the conduction time of the active discharge main loop and force the control module to actively disconnect the active discharge main loop when the time timed by the timing module reaches a set time.
In certain embodiments, the first control circuit further comprises a locking module;
the locking module includes a first conductive terminal coupled to the voltage source node, a second conductive terminal coupled to the control module, a third conductive terminal coupled to the timing module, and a fourth conductive terminal coupled to the dc input negative terminal, the locking module configured to force the control module to cause the active discharge primary circuit to be in a continuously open state after the control module causes the active discharge primary circuit to be actively disconnected.
In some embodiments, the control module includes a second switch, the timing module includes a voltage comparison circuit, and the turning on and off of the second switch is controlled by at least the second control circuit and the voltage comparison circuit.
In some embodiments, the voltage comparison circuit includes a voltage comparator, and the locking module is configured to lock an output state of the voltage comparator.
In some embodiments, the second control circuit includes a control unit and the first isolation device, and the level signal output by the control unit prompts the first isolation device to be turned on or turned off.
In some embodiments, the second control circuit further includes a second isolation device, the level signal output by the control unit causes the second isolation device to be turned on or off, the second isolation device is configured to unlock the lock module, and a control state of the second isolation device is synchronized with the first isolation device.
In a second aspect of the present invention, an embodiment of the present invention provides a control method for a discharge circuit with a protection function, where the discharge circuit includes a bus support capacitor and an active discharge circuit; the bus support capacitor is coupled between the positive direct current input terminal and the negative direct current input terminal; the active discharge circuit includes: the power circuit comprises a power resistor, a first switch, a first control circuit and a second control circuit; the power resistor is connected with the first switch in series and then coupled between the direct current input positive end and the direct current input negative end, and the power resistor, the first switch and the bus support capacitor form an active discharge main loop;
the control method comprises the following steps:
the first control circuit provides a first control signal to control the on and off of the first switch; and
when the second control circuit works normally, the second control circuit at least provides a second control signal to control the working state of the first control circuit; when the second control circuit is abnormal, the first control circuit forces the active discharge main circuit to work and prompts the active discharge main circuit to be actively disconnected after a set time.
In some embodiments, the second control circuit comprises a reset control module, the control method further comprising: when the second control circuit works normally, the reset control module can actively reset the state of the discharge circuit.
In certain embodiments, the first control circuit comprises a control module and a timing module;
the causing the active discharge main loop to be actively disconnected after the set time is passed comprises: the timing module times the conduction time of the active discharge main loop, and when the time timed by the timing module reaches the set time, the timing module forces the control module to prompt the active discharge main loop to be actively disconnected.
The invention has the beneficial effects that: the discharge circuit with the protection function and the control method thereof provided by the embodiment of the invention have the advantages that the active discharge circuit is controlled to carry out rapid discharge by utilizing the high-power resistor Rp, and the control mode is flexible. In addition, according to the discharge circuit with the protection function and the control method thereof provided by the embodiment of the invention, after the control unit MCU is abnormal, if the active discharge circuit does not successfully discharge after continuously operating for a period of time T, the active discharge circuit is actively disconnected and continuously kept disconnected, so that damage to the power resistor Rp and the system due to continuous abnormal voltage of the bus support capacitor Cp can be effectively avoided.
The discharge circuit with the protection function and the control method thereof provided by the embodiment of the invention can well solve the technical problems of the existing active discharge scheme, so that the active discharge system has richer, safer and more reliable functions.
Drawings
FIG. 1 shows a basic control block diagram of a prior art active discharge circuit;
fig. 2 is a block diagram illustrating a circuit structure of an embodiment of a discharge circuit with a protection function according to an embodiment of the present invention;
fig. 3 is a block diagram showing a circuit configuration of a further embodiment of a discharge circuit having a protection function according to an embodiment of the present invention;
fig. 4 is a block diagram showing a circuit configuration of a discharge circuit having a protection function according to still another embodiment of the present invention;
fig. 5 is a schematic circuit diagram of an embodiment of a circuit implementation of a discharge circuit according to an embodiment of the present invention;
fig. 6 is a circuit configuration diagram of another embodiment of a circuit implementation of a discharge circuit according to an embodiment of the present invention;
fig. 7 is a flowchart illustrating a control method of a discharge circuit according to an embodiment of the present invention;
fig. 8 is a flowchart illustrating a preferred embodiment of a control method of a discharge circuit according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings. Those skilled in the art will appreciate that the present invention is not limited to the drawings and the following examples.
As used herein, the term "include" and its various variants are to be understood as open-ended terms, which mean "including, but not limited to. The term "one embodiment" and the like may be understood as "at least one embodiment". The term "another embodiment" and the like may be understood as "at least one other embodiment". The terms "first", "second", etc. are used merely to distinguish different features and have no essential meaning.
Fig. 2 shows an embodiment of a discharge circuit 100 with protection. Discharge circuit 100 includes a bus support capacitor Cp and an active discharge circuit 11.
The bus support capacitor Cp includes a first conductive terminal coupled to the positive terminal BAT + of the drive motor controller dc input and a second conductive terminal coupled to the negative terminal BAT-of the drive motor controller dc input. The positive and negative terminals BAT + and BAT-of the drive motor controller DC inputs are coupled to the positive and negative poles of the power battery, respectively.
The active discharge circuit 11 includes: a power resistor Rp, a first switch K1, a first control circuit 11a, and a second control circuit 11 b.
The power resistor Rp is coupled in series with the first switch K1 between the positive terminal BAT + of the drive motor controller dc input and the negative terminal BAT-of the drive motor controller dc input. In the discharge circuit 100, the power resistor Rp, the first switch K1 and the bus bar supporting capacitor Cp form an active discharge main circuit, and it is understood that the structure of the active discharge main circuit shown in fig. 2 is a basic circuit structure, and appropriate modifications can be made on the basic circuit structure as long as the design concept and the design object of the embodiment of the present invention are satisfied, and the circuit structure described later follows this principle.
The first control circuit 11a has a first conductive terminal coupled to the node of the voltage source VCC, a second conductive terminal coupled to the negative terminal BAT-of the DC input of the driving motor controller, an output terminal providing a first control signal to the first switch K1, and an input terminal coupled to receive a second control signal. The first control circuit 11a is configured to provide at least a first control signal to control the turning on and off of the first switch K1. In discharge circuit 100, the turning on and off of first switch K1 determines whether power resistor Rp discharges bus support capacitor Cp.
The second control circuit 11b comprises an output coupled to an input of the first control circuit 11a and providing a second control signal. The second control circuit 11b is configured to provide at least a second control signal to control the first control circuit 11a to operate or not to operate when the second control circuit 11b operates normally. When the second control circuit 11b normally operates, if the second control circuit 11b provides a second control signal indicating that the first control circuit 11a operates, the first control circuit 11a controls the active discharge main circuit to discharge the bus support capacitor Cp, during the discharge process, the second control circuit 11b may provide a second control signal indicating that the first control circuit 11a does not operate at any time, and the first control circuit 11a terminates the discharge of the active discharge main circuit to the bus support capacitor Cp, which means that when the second control circuit 11b normally operates, the second control circuit 11b may control whether the active discharge main circuit discharges and the discharge time through the first control circuit 11a, so as to protect the power resistor Rp and prevent the power resistor Rp from being damaged due to overheating. When the second control circuit 11b does not work abnormally (at this time, the second control circuit 11b does not provide the second control signal), the first control circuit 11a is further configured to force the active discharge main circuit to work and prompt the active discharge main circuit to be disconnected after the set time T elapses, so that the active discharge main circuit discharges the bus support capacitor Cp on the premise of ensuring that the power resistor Rp is normal, and damage to the power resistor Rp and a system where the discharge circuit 100 is located, which is caused by continuous abnormal voltage of the bus support capacitor Cp, is avoided. The set time T needs to be determined by testing an actual circuit in combination with the maximum time that the actual loss of the power resistor Rp can endure under the worst condition in the active discharge main circuit, and the set time T should be designed to be larger than the discharge time T under the normal condition of the discharge circuit in practical application.
In the discharge circuit 100 with the protection function provided in this embodiment, the second control circuit and the first control circuit work cooperatively, so that when the second control circuit 11b is abnormal, the first control circuit 11a can prompt the active discharge main circuit to be actively disconnected, and therefore, the power resistor Rp cannot be continuously heated, and the problem of equipment damage or even fire hazard is avoided.
In a preferred embodiment of the present embodiment, the first control circuit 11a includes a second switch (refer to the switch Q1 of fig. 5), and the output terminal of the second control circuit 11b provides a second control signal to the second switch, where the second control signal is one of factors for controlling the second switch to be turned on and off. In this embodiment, the turning on and off of the second switch is synchronized with the turning on and off of the first switch K1, for example, the first switch K1 is turned on when the second switch is turned on; when the second switch is turned off, the first switch K1 is turned off, or when the second switch is turned on, the first switch K1 is turned off; the second switch is off and the first switch K1 is on.
Referring again to fig. 2, the discharge circuit 100 further includes a passive discharge circuit 12.
The passive discharge circuit 12 includes a passive discharge module 12a and a regulation circuit 12 b.
The passive discharge module 12a includes a first conductive terminal coupled to the positive terminal BAT + of the dc input of the driving motor controller and a second conductive terminal coupled to provide an electrical connection. The passive discharge module 12a is configured to passively discharge the bus bar support capacitance Cp. The passive discharge module 12a may be a passive discharge resistor, and in an actual design, the passive discharge resistor may be one resistor or may be implemented by connecting a plurality of resistors in series and parallel, and based on the same principle, the subsequent resistor may also be designed as one resistor or may be implemented by connecting a plurality of resistors in series and parallel.
The voltage regulator circuit 12b includes an input terminal coupled to the second conductive terminal of the passive discharge module 12a, an output terminal coupled to the negative terminal BAT-of the dc input of the driving motor controller, and a voltage source VCC node coupled to provide a voltage source VCC. The stabilizing circuit 12b is configured to provide a stable voltage source.
In the discharging circuit 100, the passive discharging module 12a, the voltage stabilizing circuit 12b and the bus support capacitor Cp form a passive discharging loop, and when the discharging circuit operates, the passive discharging loop continuously discharges the bus support capacitor Cp and provides a stable voltage source.
Referring now to fig. 3, fig. 3 illustrates a discharge circuit with a protection function according to yet another embodiment of the present invention. This embodiment further describes the structure of the first control circuit in the foregoing embodiment. In the present embodiment, the first control circuit 11a includes a control module 13 and a timing module 14.
The control module 13 includes a first conductive terminal coupled to the node of the voltage source VCC, a connection terminal coupled to provide an electrical connection, a control terminal coupled to the first switch K1, and a second conductive terminal coupled to the negative terminal BAT-of the dc input of the driving motor controller. The control module 13 is configured to control the turning on and off of the first switch K1.
The timing module 14 includes a first conductive terminal coupled to the node of the voltage source VCC, a second conductive terminal coupled to the negative terminal BAT-of the dc input of the driving motor controller, and a third conductive terminal coupled to the connection terminal of the control module 13. The timing module 14 is configured to time the on-time of the active discharging main circuit, and when the time timed by the timing module 14 reaches the set time T, the control module 13 is forced to prompt the active discharging main circuit to be actively turned off, so as to avoid damage to the power resistor Rp and the system where the discharging circuit 100 is located, which are caused by the continuous abnormal voltage of the bus support capacitor Cp.
Referring now to fig. 4, fig. 4 illustrates a discharge circuit with a protection function according to yet another embodiment of the present invention. This embodiment further explains the structure of the first control circuit in the aforementioned further embodiment again. In this embodiment, the first control circuit 11a further includes a locking module 15.
The locking module 15 includes a first conductive terminal coupled to the voltage source VCC node, a second conductive terminal coupled to the control module 13, a third conductive terminal coupled to the timing module 14, and a fourth conductive terminal coupled to the negative terminal BAT-of the drive motor controller dc input. The locking module 15 is configured to force the control module 13 to cause the active discharging main circuit to be in a continuously disconnected state after the control module 13 causes the active discharging main circuit to be actively disconnected, so as to further ensure the safety of the power resistor Rp and the system.
Further, the second control circuit 11b may include a reset control module (refer to the second isolation device U3 shown in fig. 6) configured to actively reset the state of the discharge circuit when the second control circuit 11b is operating normally, for example, the reset control module may unlock the locking module 15, so that the active discharge main circuit may try to actively discharge multiple times.
Referring now to fig. 5, fig. 5 shows details of an embodiment of a circuit implementation for discharge circuit 100.
The control module 13 is formed by sequentially connecting a voltage source VCC, a first switch Q1 (corresponding to the second switch in fig. 2), a sixth resistor R6, a seventh resistor R7, and a negative terminal voltage VBAT-of the dc input of the driving motor controller in series. Fig. 5 shows an example in which the first switch Q1 is a PNP transistor, and it is understood that the first switch Q1 may have other structures or other switching devices.
The control unit MCU, the tenth resistor R10, and the first isolation device U2 constitute a second control circuit 11 b. The control unit MCU has a first conductive terminal and a second conductive terminal providing an electrical connection, the tenth resistor R10 has a first conductive terminal coupled to the first conductive terminal of the control unit MCU and a second conductive terminal coupled to provide an electrical connection, the primary side of the first isolation device U2 is coupled between the second conductive terminal of the tenth resistor R10 and the second conductive terminal of the control unit MCU, and the secondary side of the first isolation device U2 is directly connected in parallel with the emitter e and the base b of the first switching tube Q1. When the level signal output by the control unit MCU makes the light emitting diode on the primary side of the first isolation device U2 conduct for operation, the phototransistor on the secondary side of the first isolation device U2 conducts. Since the secondary side of the first isolation device U2 is directly connected in parallel with the emitter E and the base B of the first switch Q1, and the conduction voltage drop of the secondary side of the first isolation device U2 is smaller than the conduction voltage drop of the gate of the first switch Q1 (i.e., from the emitter E to the base B), so that the gate of the first switch Q1 is shorted by the secondary side of the first isolation device U2, the current of the voltage source VCC flows entirely through the secondary side of the first isolation device U2, and no current flows through the gate of the first switch Q1, the first switch Q1 is in an off state, and the second switch Q2 (corresponding to the first switch K1 in fig. 2) is also in an off state. When a level signal output by the control unit MCU causes the light emitting diode on the primary side of the first isolation device U2 to be turned off and not operate (when the control unit MCU malfunctions abnormally, the light emitting diode on the primary side of the first isolation device U2 is turned off and does not operate), the secondary side of the first isolation device U2 is also turned off and does not operate, then the gate of the first switching tube Q1 will not be controlled by the short circuit of the first isolation device U2, in the circuit detail shown in fig. 5, it can be known from the following description that whether the first switching tube Q1 is turned on or off will depend on the voltage VC at the output end of the voltage comparator U1A, and when VC is equal to the voltage source VCC, the first switching tube Q1 is turned off, and the second switching tube Q2 is also turned; when VC is more than or equal to 0 and less than the voltage source VCC, the first switch tube Q1 is conducted, and the second switch tube Q2 is also conducted.
The voltage comparison circuit, the first diode D1, the eighth resistor R8, the ninth resistor R9, and the first capacitor C1 constitute the timing module 14. The ninth resistor R9 and the first capacitor C1 are connected in parallel and then connected in series with the eighth resistor R8 and the first diode D1. The first diode D1 is configured to prevent current of the first capacitor C1 from reversely discharging to the sixth resistor R6 and the seventh resistor R7, and the positive terminal of the first diode D1 is coupled between the first switch tube Q1 and the sixth resistor R6. The first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the voltage comparator U1A form a voltage comparison circuit, and the non-inverting input terminal of the voltage comparator U1A is coupled between the ninth resistor R9 and the eighth resistor R8. The voltage comparison circuit is configured to be another factor for controlling the on and off of the second switch, and when the level signal output by the control unit MCU causes the light emitting diode on the primary side of the first isolation device U2 to be turned off and not operated, whether the first switch tube Q1 is turned on or not will depend on the voltage VC at the output terminal of the voltage comparator U1A. The inverting input voltage VA of the voltage comparator U1A is the set reference voltage, and in the circuit detail shown in fig. 5, the inverting input voltage VA of the voltage comparator U1A is VCC R2/(R1+ R2). According to the operating principle of the voltage comparator U1A, when the non-inverting input terminal voltage VB of the voltage comparator U1A is greater than the inverting input terminal voltage VA, the output terminal voltage VC is at a high level, otherwise, the output terminal voltage VC is equal to 0V. At the triggering time of the active discharge circuit 11, the voltage on the first capacitor C1, that is, the voltage VB at the non-inverting input terminal of the voltage comparator U1A is 0V, and at this time VA > VB, as can be known from the operating principle of the voltage comparator U1A, the voltage VC at the output terminal of the voltage comparator U1A is 0V, that is, the voltage VC at the output terminal of the voltage comparator U1A is initially 0V. At this time, the first switching tube Q1 is turned on, the active discharge circuit 11 starts active discharge, and as time goes by, the voltage across the first capacitor C1 will gradually rise from 0V, and if the control unit MCU fails abnormally and cannot complete discharge according to the expected time T, the voltage VB across the first capacitor C1 after the set time T is greater than VA, so that the voltage VC at the output end of the voltage comparator U1A is at a high level, at this moment, VC is VD2+ VB, where VD2 is the conduction voltage drop of the second diode D2. And a timing module is arranged to realize closed-loop feedback.
The fourth resistor R4, the second diode D2, and the first capacitor C1 constitute the locking module 15. The fourth resistor R4 is coupled between the voltage source VCC and the output of the voltage comparator U1A, the second diode D2 is coupled between the output of the voltage comparator U1A and the non-inverting input, and the first capacitor C1 is coupled between the non-inverting input of the voltage comparator U1A and the negative terminal voltage VBAT-of the drive motor controller dc input. In the circuit shown in fig. 5, the locking module 15 is configured to lock the output state of the voltage comparator U1A. That is, as described in the operation principle of the previous timer module 14, when the voltage VB of the first capacitor C1 is greater than VA, if VC is VD2+ VB < voltage source VCC, then the current continues to charge the first capacitor C1 through the two paths of the fourth resistor R4 → the second diode D2 and through the first switch tube Q1 → the fifth resistor R5 → the second diode D2, the voltage of the first capacitor C1 continues to rise and keeps the state of VB greater than VA, when the voltage VB reaches a certain value, the charging current in the two paths is 0A, VC is equal to voltage source VCC and keeps the state, and when the first switch tube Q1 is in the off state, the state is always kept, and as can be known from the operation principle of the control module 13, the second switch tube Q2 is in the off state, and the main discharge loop does not work. Automatic latching is realized by arranging a locking module.
The embodiment of the invention provides a self-protection discharge circuit with closed-loop feedback and automatic latching states, which can realize that timing is started while an active discharge main loop is triggered to work, when the voltage of a bus support capacitor Cp is not released to an expected voltage value after a set time T is reached, the logic state of a control circuit is turned over, so that a first switch K is switched off, active discharge is stopped, a power resistor Rp is protected, and the stopped state is continuously locked and maintained until the voltage of the bus support capacitor Cp of the whole product is released through passive discharge. The setting of the set time T needs to be combined with the maximum time that the actual loss of the power resistor Rp can endure in the worst case of the active discharge main circuit, and the maximum time can be tested by an actual circuit, so as to set the parameters of the eighth resistor R8, the ninth resistor R9 and the first capacitor C1 in fig. 5 to determine the set time T, and the set time T should be designed to be larger than the discharge time T in the normal case of the circuit in actual application. Therefore, whether the active discharging main loop is conducted or not can be controlled when the control unit MCU is normal, so that whether the bus supporting capacitor Cp is actively discharged or not is actively controlled, and when the control unit MCU is abnormal, the active discharging main loop is triggered to conduct and work, so that the energy of the bus supporting capacitor Cp is discharged, and in addition, the damage of the power resistor Rp caused by the fact that the bus supporting capacitor Cp continuously has energy which cannot be discharged within the set time T can be effectively avoided.
Referring now to fig. 6, fig. 6 shows details of yet another embodiment of a circuit implementation for the active discharge circuit 11.
The circuit shown in fig. 6 is different from the circuit shown in fig. 5 in that a second isolation device U3 (an example of the aforementioned reset control module) is added to the circuit shown in fig. 6, the primary side of the second isolation device U3 and the primary side of the first isolation device U2 are coupled in series and then coupled between the second conductive terminal of the tenth resistor R10 and the second conductive terminal of the control unit MCU, and the secondary side of the second isolation device U3 is directly connected in parallel to two ends of the first capacitor C1. The control state of the second isolation device U3 is synchronized with the first isolation device U2. The other circuit configuration of fig. 6 is the same as that of fig. 5.
When the control unit MCU is normal, the control unit MCU controls the light emitting diodes on the primary sides of the first isolation device U2 and the second isolation device U3 to be turned on and operated through a level signal, and the phototriodes on the secondary sides of the first isolation device U2 and the second isolation device U3 are turned on, so that the voltage VB of the non-inverting input terminal of the voltage comparator U1A (i.e., the terminal voltage of the first capacitor C1) can be discharged and returned to 0V, and at this time, the first switch tube Q1 and the second switch tube Q2 are in an off state. Afterwards, if the voltage of the bus supporting capacitor Cp is abnormal, the control unit MCU controls the light emitting diodes on the primary sides of the first isolation device U2 and the second isolation device U3 to be turned off and not to work through a level signal, the phototriodes on the secondary sides of the first isolation device U2 and the second isolation device U3 are turned off, at this time, the first switch tube Q1 and the second switch tube Q2 are in a conducting state, and the working condition of the active discharge circuit is the same as the working condition (not described) described in fig. 5, so that the active discharge main circuit can be turned on to realize active discharge, and the active discharge main circuit can be turned off after a set time T to protect the power resistor Rp. If the voltage of the bus support capacitor Cp is still abnormal after one active discharge, when the control unit MCU is normal, the control unit MCU controls the light emitting diodes on the primary sides of the first isolation device U2 and the second isolation device U3 to conduct and operate through the level signal, so that the voltage VB on the non-inverting input terminal of the voltage comparator U1A can be discharged and returned to 0V, the voltage VC on the output terminal of the voltage comparator U1A returns to 0V, and then the control unit MCU controls the light emitting diodes on the primary sides of the first isolation device U2 and the second isolation device U3 to be turned off and not operate through the level signal, so as to promote the active discharge of the active discharge main circuit again, thereby accelerating the discharge of the voltage of the bus support capacitor Cp while protecting the power resistor Rp (the specific working process can refer to the foregoing description).
Returning to the circuit shown in fig. 5, the active discharge circuit only performs active discharge control once when the control unit MCU is normal but the voltage of the bus supporting capacitor Cp is continuously abnormal, because if the voltage of the bus supporting capacitor Cp is continuously abnormal, the state of the voltage comparator U1A keeps VC equal to the voltage source VCC, i.e., the first switch Q1 and the second switch Q2 are continuously disconnected, so that the control unit MCU cannot try to perform active discharge again after active discharge once. In the active discharge circuit structure shown in fig. 6, because the second isolation device U3 is provided, when the voltage of the bus support capacitor Cp is continuously abnormal, active discharge can be tried for many times under the normal condition of the control unit MCU, so that the control flexibility is greatly improved, and a better protection circuit is facilitated.
Details of embodiments of circuit implementations for discharge circuit 100 are described more fully below in conjunction with fig. 5 and 6.
Fig. 5 shows an active discharge circuit comprising: the power circuit comprises a power resistor Rp, a second switch tube Q2, a control unit MCU, a first isolation device U2, a first switch tube Q1, a first diode D1, a second diode D2, a voltage comparator U1A, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10. The first switch transistor Q1 is a triode, the first switch transistor Q1 is shown as a PNP triode, the second switch transistor Q2 is a MOSFET transistor, and the second switch transistor Q2 is shown as an N-channel MOSFET transistor. The N-channel MOSFET comprises a gate electrode G, a drain electrode D and a source electrode S. The PNP type triode comprises an emitter E, a base B and a collector C.
One end of the power resistor Rp is connected with a positive terminal BAT of a direct current input of the driving motor controller, the other end of the power resistor Rp is connected with a drain D of the second switch tube Q2, a source S of the second switch tube Q2 is connected with a negative terminal BAT of the direct current input of the driving motor controller, a gate G of the second switch tube Q2 is connected with one end of the sixth resistor R6 and one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected with a negative terminal BAT of the direct current input of the driving motor controller, and the other end of the sixth resistor R6 is connected with a collector C of the first switch tube Q1 and a positive electrode of the first diode D1; one end of a first resistor R1 is connected with a voltage source VCC, the other end is connected with one end of a second resistor R2 and one end of a third resistor R3, the other end of the third resistor R3 is connected with the inverting input end of a voltage comparator U1A, the other end of the second resistor R2 is connected with the negative terminal BAT of the DC input of the driving motor controller, the non-inverting input end of the voltage comparator U1A is connected with one end of a ninth resistor R9, one end of an eighth resistor R8, one end of a first capacitor C1 and the negative electrode of a second diode D2, the other end of the ninth resistor R9 and the other end of the first capacitor C1 are connected with the negative terminal BAT of the DC input of the driving motor controller, the other end of the eighth resistor R8 is connected with the negative electrode of a first diode D1, the output end of the voltage comparator U1 7378 is connected with the positive electrode of a second diode D6866, one end of a fifth resistor R5 and one end of a fourth resistor R4, the other end of the fourth resistor R36, the other end of the fifth resistor R5 is connected with a base electrode B of the first switch tube Q1; one end of the control unit MCU is connected with the anode of the light emitting diode at the primary side of the first isolation device U2 through a tenth resistor R10, the cathode of the light emitting diode is connected with the other end of the control unit MCU, the collector of the phototriode at the secondary side of the first isolation device U2 is connected with the emitter E of the first switch tube Q1, and the emitter of the phototriode at the secondary side of the first isolation device U2 is connected with the base B of the first switch tube Q1.
As shown in the figure, a positive terminal BAT + and a negative terminal BAT-of the direct current input of the driving motor controller are respectively connected with the positive pole and the negative pole of the power battery, and the bus supporting capacitor Cp is connected in parallel to the direct current bus of the driving motor controller, namely is connected between the positive terminal BAT + and the negative terminal BAT-of the direct current input of the driving motor controller.
In the figure, an eleventh resistor R11, a zener diode Z1 and an energy storage zener capacitor C2 form a basic passive discharge circuit, the eleventh resistor R11 is a passive discharge resistor, and the passive discharge resistor can be realized by connecting a plurality of resistors in series and parallel in practical design. The voltage stabilizing diode Z1 and the energy storage voltage stabilizing capacitor C2 are connected in parallel to form a voltage stabilizing circuit, and the specific connection mode given in the figure is as follows: one end of the eleventh resistor R11 is connected with the positive terminal BAT + of the DC input of the driving motor controller, the other end is connected with the negative electrode of the voltage stabilizing diode Z1 and one end of the energy storage voltage stabilizing capacitor C2, the positive electrode of the voltage stabilizing diode Z1 and the other end of the energy storage voltage stabilizing capacitor C2 are connected with the negative terminal BAT-of the DC input of the driving motor controller, and the voltage at the two ends of the voltage stabilizing diode Z1 is used as a voltage source VCC. Therefore, the passive discharge circuit generates a voltage source VCC and functions to stabilize the voltage.
In the active discharge circuit shown in fig. 5, six control paths are included.
A first control path: the voltage source VCC → the first switch tube Q1 → the sixth resistor R6 → the seventh resistor R7 → the negative terminal voltage VBAT of the dc input of the drive motor controller, and the first control path constitutes a control loop for the second switch tube Q2 (i.e., the switch K1), wherein the on and off states of the second switch tube Q2 determine whether the power resistor Rp discharges the bus bar support capacitor Cp.
A second control path: the control unit MCU → the tenth resistor R10 → the first isolation device U2, and the second control path constitutes a control loop for the first switch Q1, i.e. controls the on and off of the first switch Q1. When a level signal output by the control unit MCU causes a light emitting diode on the primary side of the first isolation device U2 to be turned on for operation, a phototransistor on the secondary side of the first isolation device U2 is turned on, and since the secondary side of the first isolation device U2 is directly connected in parallel with the emitter E and the base B of the first switching tube Q1, and the conduction voltage drop of the secondary side of the first isolation device U2 is smaller than the conduction voltage drop of the gate of the first switching tube Q1 (i.e., from the emitter E to the base B), the gate of the first switching tube Q1 is short-circuited by the secondary side of the first isolation device U2, the current of the voltage source VCC all flows through the secondary side of the first isolation device U2, and the gate of the first switching tube Q1 does not flow, so that the first switching tube Q1 is in an off state, and the second switching tube Q2 is also in an off state. When the level signal output by the control unit MCU turns off the light emitting diode on the primary side of the first isolation device U2 and does not operate, the secondary side of the first isolation device U2 also turns off and does not operate, so the gate of the first switch Q1 will not be controlled by the short circuit of the first isolation device U2, and at this time, whether the first switch Q1 is turned on or off will depend on the voltage VC at the output terminal of the voltage comparator U1A (when VC is equal to the voltage source VCC, the first switch Q1 is turned off, and when VC is equal to 0 and less than the voltage source VCC, the first switch Q1 is turned on).
A third control path: the positive end voltage VBAT + → power resistor Rp → the second switch tube Q2 → the negative end voltage VBAT- → bus bar support capacitor Cp of the drive motor controller DC input, and the third control path constitutes a main discharge circuit of the active discharge circuit.
A fourth control path: the fourth control path forms a voltage comparison circuit, the voltage VA at the inverting input end of the voltage comparator U1A is a set reference voltage, and VA is VCC R2/(R1+ R2).
A fifth control path: a first diode D1, an eighth resistor R8, a ninth resistor R9 and a first capacitor C1, wherein the fifth control path is used for timing the action moment of the main discharging loop, and the first diode D1 is used for preventing the current of the first capacitor C1 from reversely discharging to the sixth resistor R6 and the seventh resistor R7. At the triggering time of the active discharge circuit 11, the voltage across the first capacitor C1, i.e., the voltage VB at the non-inverting input terminal of the voltage comparator U1A is 0V, and at this time VA > VB, the voltage VC at the output terminal of the voltage comparator U1A is 0V according to the operating principle of the voltage comparator U1A, i.e., the initial state of the voltage VC at the output terminal of the voltage comparator U1A is 0V. If the first switching tube Q1 is turned on to start active discharge at this time, the voltage across the first capacitor C1 will gradually rise from 0V with the passage of time, and if the control unit MCU fails abnormally and cannot complete discharge at the expected time T, the voltage VB across the first capacitor C1 after the time T is over is greater than VA, so that the voltage VC at the output end of the voltage comparator U1A is at a high level, and at this moment, VC is VD2+ VB, where VD2 is the conduction voltage drop of the second diode D2.
A sixth control path: the fourth resistor R4, the second diode D2 and the first capacitor C1, and the sixth control path realize the locking of the output state of the voltage comparator U1A. That is, as described in the fifth control path, when the voltage VB of the first capacitor C1 is greater than VA, if VC is VD2+ VB < voltage source VCC, then current continues to charge the first capacitor C1 through the two paths of the fourth resistor R4 → the second diode D2 and through the first switch tube Q1 → the fifth resistor R5 → the second diode D2, the voltage of the first capacitor C1 continues to rise and maintains the state of VB greater than VA, when the voltage VB reaches a certain value, the charging current of the two paths is 0A, VC is greater than the voltage source VCC and maintains the state, when the first switch tube Q1 is in the off state, the state is maintained all the time, and as can be known from the first control path, the second switch tube Q2 is in the off state, and the main discharge circuit does not work.
The working principle of each part of the active discharge circuit is described above, and the control state of the entire active discharge circuit is analyzed as follows:
1. when the control unit MCU is normal
The control unit MCU controls the first isolation device U2 to be switched on and operated through signals, and the first switch tube Q1 is in an off state, the second switch tube Q2 is in an off state and the active discharge circuit does not work by combining a second control path.
The control unit MCU controls the first isolation device U2 to stop working through a signal, and the second control path, the fourth control path, the fifth control path and the sixth control path are combined to know that the second switching tube Q2 completes an active discharge task after conducting working for T time, or does not complete the discharge task after T time, so that the second switching tube Q2 is continuously disconnected to protect the power resistor Rp.
2. When the control unit MCU is abnormal (e.g. power down)
At this time, the first isolation device U2 is in an uncontrolled off-state by default, and combining the second control path, the fourth control path, the fifth control path, and the sixth control path, the second switch Q2 completes the active discharging task after the on-state operation time T, or does not complete the discharging task after the time T, so that the second switch Q2 is continuously turned off to protect the power resistor Rp.
In the circuit structure shown in fig. 6, a second isolation device U3 is added on the basis of fig. 5, and the control state of the second isolation device U3 is synchronous with that of the first isolation device U2, wherein one end of the control unit MCU is connected to the anode of the light emitting diode on the primary side of the first isolation device U2 through a tenth resistor R10, the cathode of the light emitting diode on the primary side of the first isolation device U2 is connected to the anode of the light emitting diode on the primary side of the second isolation device U3, the cathode of the light emitting diode on the primary side of the second isolation device U3 is connected to the other end of the control unit MCU, the collector of the phototransistor on the secondary side of the first isolation device U2 is connected to the emitter E of the first switching tube Q1, the emitter of the phototransistor on the secondary side of the first isolation device U2 is connected to the base B of the first switching tube Q1, the collector of the phototransistor on the secondary side of the second isolation device U3 is connected to the one end of the first capacitor C1, and the emitter of the phototransistor on the secondary side of the second isolation device U3 is connected And (4) an end. The other circuit configurations are the same as those in embodiment 1. The active discharge circuit (or active discharge main loop) shown in fig. 6 may implement multiple attempts of active discharge under the normal condition of the control unit MCU.
Fig. 7 is a flowchart illustrating a control method of a discharge circuit with a protection function according to an embodiment of the present invention. The discharge circuit comprises a bus supporting capacitor and an active discharge circuit; the bus support capacitor is coupled between the positive direct current input terminal and the negative direct current input terminal; the active discharge circuit includes: the power circuit comprises a power resistor, a first switch, a first control circuit and a second control circuit; the power resistor is connected with the first switch in series and then coupled between the direct current input positive end and the direct current input negative end, and the power resistor, the first switch and the bus support capacitor form an active discharge main loop;
the control method comprises the following steps:
the first control circuit provides a first control signal to control the on and off of the first switch; and
when the second control circuit works normally, the second control circuit at least provides a second control signal to control the working state of the first control circuit; when the second control circuit is abnormal, the first control circuit forces the active discharge main circuit to work and prompts the active discharge main circuit to be actively disconnected after a set time.
In a preferred embodiment, as shown in fig. 8, the second control circuit includes a reset control module, and the control method further includes: when the second control circuit works normally, the reset control module can actively reset the state of the discharge circuit.
In another preferred embodiment, the first control circuit comprises a control module and a timing module;
the causing the active discharge main loop to be actively disconnected after the set time is passed comprises: the timing module times the conduction time of the active discharge main loop, and when the time timed by the timing module reaches the set time, the timing module forces the control module to prompt the active discharge main loop to be actively disconnected.
When the second control circuit works normally, the second control circuit at least provides a second control signal to control the working state of the first control circuit, and the reset control module can actively reset the state of the discharge circuit; when the second control circuit is abnormal, the first control circuit forces the main active discharge circuit to work and prompts the main active discharge circuit to be actively disconnected after a set time
The control method of the discharge circuit with protection function provided in this embodiment is the same as the description of the discharge circuit with protection function provided in the foregoing embodiment, and for the sake of brevity, no further description is provided herein, and a person skilled in the art can understand the implementation of the corresponding control method according to the description of the foregoing embodiment.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (13)
1. A discharge circuit with a protection function is characterized by comprising a bus supporting capacitor, an active discharge circuit and a passive discharge circuit;
the bus bar support capacitor comprises a first conductive terminal coupled to the positive end of the direct current input and a second conductive terminal coupled to the negative end of the direct current input;
the active discharge circuit includes: the power circuit comprises a power resistor, a first switch, a first control circuit and a second control circuit;
the power resistor is connected with the first switch in series and then coupled between the direct current input positive end and the direct current input negative end, and the power resistor, the first switch and the bus support capacitor form an active discharge main loop;
the first control circuit comprises a first conductive terminal coupled to the voltage source node, a second conductive terminal coupled to the negative terminal of the direct current input, an output terminal providing a first control signal to the first switch, and an input terminal coupled to receive a second control signal, the first control circuit is configured to provide at least the first control signal to control the first switch to be turned on and off;
the second control circuit comprises an output end which is coupled to the input end of the first control circuit to provide a second control signal for the first control circuit, the second control circuit is configured to provide at least the second control signal to control the working state of the first control circuit when the second control circuit works normally, wherein if the second control circuit provides the second control signal which indicates that the first control circuit works, the first control circuit controls the main active discharging loop to discharge the bus supporting capacitor, and during the discharging process, the second control circuit can provide the second control signal which indicates that the first control circuit does not work at any time, and the first control circuit stops the main active discharging loop from discharging the bus supporting capacitor; the first control circuit is also configured to force the active discharge main circuit to work when the second control circuit is abnormal, and disconnect the first switch after a set time, so as to prompt the active discharge main circuit to be actively disconnected, terminate the active discharge, and continuously lock and maintain the termination state until the voltage of the bus supporting capacitor is discharged through the passive discharge circuit, so as to protect the power resistor.
2. The discharge circuit of claim 1, wherein the first control circuit comprises a second switch, an output of the second control circuit providing a second control signal to the second switch, an on and off portion of the second switch being controlled by the second control signal, the on and off of the second switch being synchronized with the on and off action of the first switch.
3. The discharge circuit of claim 1, wherein the second control circuit comprises a reset control module configured to actively reset the state of the discharge circuit when the second control circuit is operating normally.
4. The discharge circuit of claim 1, wherein the passive discharge circuit comprises a passive discharge module and a voltage stabilizing circuit;
the passive discharge module comprises a first conductive terminal coupled to the positive end of the direct current input and a second conductive terminal coupled to provide an electrical connection, and is configured to passively discharge the bus support capacitor;
the voltage stabilizing circuit comprises an input end coupled to the second conductive terminal of the passive discharge module, an output end coupled to the negative end of the direct current input, and a voltage source node coupled to provide a voltage source, and is configured to provide a stable voltage source.
5. The discharge circuit of claim 1, wherein the first control circuit comprises a control module and a timing module;
the control module comprises a first conductive terminal coupled to the voltage source node, a connection terminal coupled to provide an electrical connection, a control terminal coupled to the first switch, and a second conductive terminal coupled to the negative terminal of the DC input;
the timing module comprises a first conductive terminal coupled to the voltage source node, a second conductive terminal coupled to the DC input negative terminal and a third conductive terminal coupled to the connection terminal of the control module, and is configured to time the conduction time of the active discharge main loop and force the control module to actively disconnect the active discharge main loop when the time timed by the timing module reaches a set time.
6. The discharge circuit of claim 5, wherein the first control circuit further comprises a locking module;
the locking module includes a first conductive terminal coupled to the voltage source node, a second conductive terminal coupled to the control module, a third conductive terminal coupled to the timing module, and a fourth conductive terminal coupled to the dc input negative terminal, the locking module configured to force the control module to cause the active discharge primary circuit to be in a continuously open state after the control module causes the active discharge primary circuit to be actively disconnected.
7. The discharge circuit of claim 6, wherein the control module comprises a second switch, the timing module comprises a voltage comparison circuit, and the turning on and off of the second switch is controlled by at least the second control circuit and the voltage comparison circuit.
8. The discharge circuit of claim 7, wherein the voltage comparison circuit comprises a voltage comparator, and wherein the locking module is configured to lock the output state of the voltage comparator.
9. The discharge circuit of claim 6, wherein the second control circuit comprises a control unit and the first isolation device, and the level signal output by the control unit causes the first isolation device to be turned on or turned off.
10. The discharge circuit of claim 9, wherein the second control circuit further comprises a second isolation device, the level signal output by the control unit causes the second isolation device to be turned on or off, the second isolation device is configured to unlock the lock module, and the control state of the second isolation device is synchronized with the first isolation device.
11. A control method of a discharge circuit with a protection function is characterized in that the discharge circuit comprises a bus supporting capacitor, an active discharge circuit and a passive discharge circuit; the bus support capacitor is coupled between the positive direct current input terminal and the negative direct current input terminal; the active discharge circuit includes: the power circuit comprises a power resistor, a first switch, a first control circuit and a second control circuit; the power resistor is connected with the first switch in series and then coupled between the direct current input positive end and the direct current input negative end, and the power resistor, the first switch and the bus support capacitor form an active discharge main loop; the first control circuit comprises a first conductive terminal coupled to the voltage source node, a second conductive terminal coupled to the negative terminal of the DC input, an output terminal providing a first control signal to the first switch, and an input terminal coupled to receive a second control signal; the second control circuit includes an output coupled to the input of the first control circuit to provide a second control signal to the first control circuit;
the control method comprises the following steps:
the first control circuit provides a first control signal to control the on and off of the first switch; and
when the second control circuit works normally, the second control circuit at least provides a second control signal to control the working state of the first control circuit, wherein if the second control circuit provides the second control signal indicating that the first control circuit works, the first control circuit controls the main active discharge loop to discharge to the bus supporting capacitor, and in the discharge process, the second control circuit can provide the second control signal indicating that the first control circuit does not work at any time, and the first control circuit stops the main active discharge loop from discharging to the bus supporting capacitor; when the second control circuit is abnormal, the first control circuit forces the active discharge main circuit to work and turns off the first switch after a set time, so that the active discharge main circuit is enabled to be actively turned off, the active discharge is stopped, and the stop state is continuously locked and kept until the voltage of the bus supporting capacitor is discharged through the passive discharge circuit, so as to protect the power resistor.
12. The control method of claim 11, wherein the second control circuit comprises a reset control module, the control method further comprising: when the second control circuit works normally, the reset control module can actively reset the state of the discharge circuit.
13. The control method of claim 11, wherein the first control circuit comprises a control module and a timing module;
the causing the active discharge main loop to be actively disconnected after the set time is passed comprises: the timing module times the conduction time of the active discharge main loop, and when the time timed by the timing module reaches the set time, the timing module forces the control module to prompt the active discharge main loop to be actively disconnected.
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| CN110920398A (en) * | 2019-11-11 | 2020-03-27 | 苏州汇川联合动力***有限公司 | Active discharge circuit and power electronic equipment |
| CN113119802B (en) * | 2019-12-31 | 2024-01-09 | 比亚迪股份有限公司 | Vehicle, energy conversion device, and control method therefor |
| CN111409463B (en) * | 2020-03-31 | 2023-09-15 | 上海电气集团股份有限公司 | Electric automobile and discharge protection circuit thereof |
| CN111660827B (en) * | 2020-06-03 | 2021-07-06 | 东风小康汽车有限公司重庆分公司 | State machine for range-extended electric automobile and range-extended electric automobile |
| CN113676116B (en) * | 2021-08-03 | 2023-10-10 | 武汉光庭信息技术股份有限公司 | Active discharge circuit with fault diagnosis |
| CN115833285B (en) * | 2021-11-01 | 2023-12-08 | 宁德时代新能源科技股份有限公司 | Bleeder circuit, battery management system, battery, protection method and electricity utilization device |
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| US5572735A (en) * | 1994-05-27 | 1996-11-05 | Ast Research, Inc. | Method and apparatus for discharging the output voltage of a DC power supply |
| JP2001008460A (en) * | 1999-06-17 | 2001-01-12 | Yaskawa Electric Corp | Brake transistor fault detecting circuit |
| CN103219877B (en) * | 2012-01-20 | 2016-06-01 | 台达电子企业管理（上海）有限公司 | A kind of capacitor discharging circuit and changer |
| TWI481142B (en) * | 2012-06-19 | 2015-04-11 | Richtek Technology Corp | Bleeding circuit and method for reducing power consumption of an emi filter |
| JP6459945B2 (en) * | 2015-12-11 | 2019-01-30 | スズキ株式会社 | Control device for electric vehicle |
| CN106787657A (en) * | 2016-12-29 | 2017-05-31 | 上海新时达电气股份有限公司 | Vehicle-mounted drive control device capacitor discharging circuit |
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Address after: 510000 No.8 Songgang street, Cencun, Tianhe District, Guangzhou City, Guangdong Province Applicant after: GUANGZHOU XPENG AUTOMOBILE TECHNOLOGY Co.,Ltd. Address before: 510640 Xiaopeng Automobile Intelligent Industrial Park, No. 8 Songgang Street, Changxing Street, Tianhe District, Guangzhou City, Guangdong Province Applicant before: GUANGZHOU XPENG AUTOMOBILE TECHNOLOGY Co.,Ltd. |
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