Active short-circuit circuit, method and vehicle

Abstract

The present invention discloses an active short-circuit circuit, method and vehicle. The circuit includes a power conversion circuit connected to the motor input end, the power conversion circuit includes six bridge arms, and the circuit also includes: a backup power supply for supplying power to the first drive circuit, the second drive circuit and the third drive circuit in the lower three bridge arms, and the backup power supply is at least grounded with the first drive circuit; a control module for outputting a first active short-circuit signal to the first drive circuit; a first operational amplifier module for generating a second active short-circuit signal output to the second drive circuit based on the first active short-circuit signal and the first ground potential; a second operational amplifier module for generating a third active short-circuit signal output to the third drive circuit based on the first active short-circuit signal and the second ground potential. The present invention solves the technical problem of signal interference in the prior art caused by the lower three bridge drive circuits using a common ground power supply and driving the lower three bridge drive circuits by the same active short-circuit signal.

Description

Technical Field

[0001] The present invention relates to the field of drive motors, and in particular to an active short-circuit circuit, method, and vehicle. Background Art

[0002] In electric vehicle motor controllers and other power conversion devices, the main power conversion part is usually composed of 6 semiconductor switching devices (or 6 parallel units of several switching devices), such as Figure 1 As shown. Figure 1 In the six bridge arms, the emitters of the three lower bridges are at the same node on the main circuit. When the backup power supply is working, the lower three bridges use a common ground power supply. However, in high-power converters, the emitters of the insulated gate bipolar transistors (IGBTs) in the actual lower three bridges are usually connected to the N pole of the busbar through copper busbar screws, etc., which will be equivalent to a certain amount of stray inductance (such as Figure 2 In high-power converters, the moment a switch is turned on and off, a large current change occurs, inducing a voltage difference across the stray inductance. Therefore, if the active short-circuit signal is sent to the three lower bridge driver chips using the same signal, the ground potential deviation could lead to false triggering of the active short-circuit or failure of the active short-circuit, affecting functional safety and preventing the system from operating normally.

[0003] To address the above-mentioned problems, no effective solutions have been proposed so far. Summary of the Invention

[0004] Embodiments of the present invention provide an active short-circuit circuit, method, and vehicle to at least address the technical problem in the prior art of signal interference caused by the lower three-bridge drive circuit using a common ground power supply and driving the lower three-bridge drive circuit with the same active short-circuit signal.

[0005] According to one aspect of an embodiment of the present invention, an active short-circuit circuit is provided, comprising a power conversion circuit connected to an input terminal of a motor, wherein the power conversion circuit comprises six bridge arms, and each bridge arm comprises at least an insulated gate bipolar transistor (IGBT) and a drive circuit for controlling the on / off of the IGBT, and the circuit further comprises: a backup power supply for supplying power to a first drive circuit, a second drive circuit, and a third drive circuit in the lower three bridge arms, wherein the backup power supply shares a common ground with at least the first drive circuit; a control module for outputting a first active short-circuit signal to the first drive circuit, so that the first drive circuit controls the on / off of a first IGBT corresponding to the first drive circuit according to the first active short-circuit signal; a first operational amplifier module for controlling the on / off of a first IGBT corresponding to the first drive circuit based on the first active short-circuit signal; The short-circuit signal and the first ground potential are used to generate a second active short-circuit signal output to the second drive circuit, so that the second drive circuit controls the on and off of the second IGBT corresponding to the second drive circuit according to the second active short-circuit signal, wherein the first ground potential is the reference ground potential of the second drive circuit; the second operational amplifier module is used to generate a third active short-circuit signal output to the third drive circuit based on the first active short-circuit signal and the second ground potential, so that the third drive circuit controls the on and off of the third IGBT corresponding to the third drive circuit according to the third active short-circuit signal, wherein the second ground potential is the reference ground potential of the third drive circuit, and when the first IGBT, the second IGBT and the third IGBT are all turned on, active short circuit of the motor is achieved.

[0006] Furthermore, the output end of the first drive circuit is connected to the gate of the first IGBT, and the first drive circuit and the emitter of the first IGBT share a common ground; the output end of the second drive circuit is connected to the gate of the second IGBT, and the second drive circuit and the emitter of the second IGBT share a common ground; the output end of the second drive circuit is connected to the gate of the third IGBT, and the third drive circuit and the emitter of the third IGBT share a common ground.

[0007] Furthermore, the first operational amplifier module and the second operational amplifier module are both differential operational amplifier circuits.

[0008] Furthermore, the first input terminal of the first operational amplifier module is connected to the output terminal of the control module through a first resistor, the second input terminal of the first operational amplifier module is connected to the emitter of the first IGBT through a second resistor, and the second input terminal of the first operational amplifier module is connected to the emitter of the second IGBT through a third resistor, the output terminal of the first operational amplifier module is connected to the input terminal of the second driving circuit, and the output terminal of the first operational amplifier module is connected to the first input terminal of the first operational amplifier module through a fourth resistor, and the ground terminal of the first operational amplifier module is connected to the emitter of the second IGBT.

[0009] Furthermore, the first input terminal of the second operational amplifier module is connected to the output terminal of the control module through the fifth resistor, the second input terminal of the second operational amplifier module is connected to the emitter of the first IGBT through the sixth resistor, and the second input terminal of the second operational amplifier module is connected to the emitter of the third IGBT through the seventh resistor, and the output terminal of the second operational amplifier module is connected to the first input terminal of the second operational amplifier module through the eighth resistor, and the ground terminal of the second operational amplifier module is connected to the emitter of the third IGBT.

[0010] Furthermore, the resistance values ​​of the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor, the sixth resistor, the seventh resistor and the eighth resistor are equal.

[0011] According to another aspect of an embodiment of the present invention, an active short-circuit method is also provided, which is applied to the above-mentioned active short-circuit circuit, including: outputting a first active short-circuit signal to the first drive circuit, so that the first drive circuit controls the on-off of the first IGBT corresponding to the first drive circuit according to the first active short-circuit signal; determining a second active short-circuit signal based on the first active short-circuit signal and the first ground potential, and outputting the second active short-circuit signal to the second drive circuit, so that the second drive circuit controls the on-off of the second IGBT corresponding to the second drive circuit according to the second active short-circuit signal; determining a third active short-circuit signal based on the first active short-circuit signal and the second ground potential, and outputting the third active short-circuit signal to the third drive circuit, so that the third drive circuit controls the on-off of the third IGBT corresponding to the third drive circuit according to the third active short-circuit signal, wherein when the first IGBT, the second IGBT and the third IGBT are all turned on, active short-circuiting of the motor is achieved.

[0012] Furthermore, the active short-circuit method further includes: determining a second active short-circuit signal according to the first active short-circuit signal, a third ground potential, and the first ground potential, wherein the third ground potential is a reference ground potential of the first driving circuit.

[0013] Furthermore, the active short-circuit method further includes: determining a third active short-circuit signal according to the first active short-circuit signal, the third ground potential, and the second ground potential.

[0014] According to another aspect of an embodiment of the present invention, a vehicle is provided, in which the above-mentioned active short-circuit circuit is applied.

[0015] In an embodiment of the present invention, different active short-circuit signals are output to different drive circuits in the lower three bridges. A first active short-circuit signal is output to the first drive circuit through the control module, so that the first drive circuit controls the on / off of a first IGBT corresponding to the first drive circuit according to the first active short-circuit signal. Then, a second active short-circuit signal is determined by the first operational amplifier module based on the first active short-circuit signal and a first ground potential, and the second active short-circuit signal is output to the second drive circuit, so that the second drive circuit controls the on / off of a second IGBT corresponding to the second drive circuit according to the second active short-circuit signal. Then, a third active short-circuit signal is determined by the second operational amplifier module based on the first active short-circuit signal and a second ground potential, and the third active short-circuit signal is output to the third drive circuit, so that the third drive circuit controls the on / off of a third IGBT corresponding to the third drive circuit according to the third active short-circuit signal. Thus, when the first, second, and third IGBTs are all turned on, active short-circuiting of the motor is achieved. Among them, the first ground potential is the reference ground potential of the second drive circuit, the second ground potential is the reference ground potential of the third drive circuit, and the first drive circuit, the second drive circuit and the third drive circuit in the lower three bridge arms are powered by a backup power supply.

[0016] In the above process, by directly outputting the first active short-circuit signal to the first drive circuit, then outputting the second active short-circuit signal, which is different from the first active circuit, to the second drive circuit, and outputting the third active short-circuit signal, which is different from the first active circuit, to the third drive circuit, that is, by sending three different active circuit signals to different drive circuits in different lower three bridges, the first drive circuit, the second drive circuit, and the third drive circuit can make the same judgment results on the voltage of the received active short-circuit signal based on their own reference ground potentials, thereby effectively achieving anti-interference of the active short-circuit signal and avoiding the phenomenon that the first drive circuit, the second drive circuit, and the third drive circuit reach different judgment results when receiving the same active short-circuit signal due to deviations in the reference ground potential. In addition, because each drive circuit determines the voltage value of the active short-circuit signal based on its corresponding reference ground potential, the second active short-circuit signal is determined based on the first active short-circuit signal and the reference ground potential of the second drive circuit, and the third active short-circuit signal is determined based on the first active short-circuit signal and the reference ground potential of the third drive circuit, thereby achieving accurate determination of the active short-circuit signal sent to the drive circuit, thereby further improving the signal anti-interference effect.

[0017] It can be seen that the solution provided in the present application achieves the purpose of outputting different active short-circuit signals to different driving circuits in the lower three bridges, thereby realizing the technical effect of anti-interference of the active short-circuit signal, and thus solving the technical problem of signal interference caused by the lower three bridge driving circuits using a common ground power supply and driving the lower three bridge driving circuits by the same active short-circuit signal in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of an active short-circuit circuit in the prior art;

[0020] Figure 2 It is a schematic diagram of another active short-circuit circuit in the prior art;

[0021] Figure 3 is a schematic diagram of an optional active short-circuit circuit according to an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of an optional active short-circuit circuit according to an embodiment of the present invention;

[0023] Figure 5 is a schematic diagram of an optional active short-circuit method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] Example 1

[0027] According to an embodiment of the present invention, an embodiment of an active short circuit is provided. In the active short circuit, Figure 3 As shown, it includes a power conversion circuit connected to the motor input terminal, wherein the power conversion circuit includes six bridge arms, and each bridge arm is composed of at least an insulated gate bipolar transistor IGBT (such as Figure 3 S1-S6 in the figure) and the drive circuit for controlling the on and off of the IGBT (such as Figure 3 The collector of the upper three-bridge IGBT of the power conversion circuit and the lead-out terminal (i.e. the P-pole) of the busbar / busbar capacitor are connected. Figure 3 The emitter of the lower three-bridge IGBT of the power conversion circuit is connected to the lead-out terminal (i.e. the other end (N pole) of the busbar / busbar capacitor) Figure 3 N1, N2 and N3 in are connected, and Figure 3 The U, V, and W in the figure are the terminals of the three windings of the three-phase motor. Figure 3 As shown, the active short-circuit circuit also includes:

[0028] The backup power supply is used to supply power to the first drive circuit, the second drive circuit and the third drive circuit in the lower three bridge arms, and the backup power supply shares a common ground with at least the first drive circuit.

[0029] Optionally, the output terminals of the backup power supply are connected to the first drive circuit (ie Figure 3 The first input terminal of the driving circuit 4) and the second driving circuit (ie Figure 3 The first input terminal of the driving circuit 5) and the third driving circuit (ie Figure 3 The first input terminal of the driving circuit 6) is connected to power the first driving circuit, the second driving circuit and the third driving circuit.

[0030] In addition, the backup power supply shares a common ground with at least the first drive circuit. Optionally, the backup power supply may share a common ground with only the first drive circuit, but not with the second drive circuit and the third drive circuit. In this case, the second drive circuit and the third drive circuit also do not share a common ground.

[0031] The control module is used to output a first active short-circuit signal to the first drive circuit, so that the first drive circuit controls the on and off of a first IGBT corresponding to the first drive circuit according to the first active short-circuit signal.

[0032] Optionally, the output terminal of the control module is connected to the second input terminal of the first drive circuit. The control module is configured to output a first active short-circuit signal ASC_UB to the first drive circuit, and the control module uses a third ground potential GND_UB as a reference ground potential, wherein the third ground potential GND_UB is the reference ground potential of the first drive circuit. The first drive circuit is configured to determine a voltage level output to the first IGBT S4 based on the first active short-circuit signal ASC_UB. Specifically, when the first drive circuit determines that the voltage of the first active short-circuit signal ASC_UB is within a first preset range, the first drive circuit may output a high voltage level to the first IGBT S4 to turn on the first IGBT S4. When the first drive circuit determines that the voltage of the first active short-circuit signal ASC_UB is within a second preset range, the first drive circuit may output a low voltage level to the first IGBT S4 to turn off the first IGBT S4. The first preset range and the second preset range do not overlap.

[0033] The first operational amplifier module is configured to generate a second active short-circuit signal, based on the first active short-circuit signal and the first ground potential, to be output to the second drive circuit, so that the second drive circuit controls the on and off of a second IGBT corresponding to the second drive circuit according to the second active short-circuit signal, wherein the first ground potential is a reference ground potential of the second drive circuit.

[0034] Optionally, the first operational amplifier module may be a differential operational amplifier circuit. Specifically, the first operational amplifier module may use the first ground potential GND_VB as its own reference ground potential, and then generate a second active short-circuit signal ASC_VB based on the first active short-circuit signal ASC_UB and the third ground potential GND_UB, outputting it to the second driver circuit. The second driver circuit is configured to determine the voltage level output to the second IGBT S5 based on the second active short-circuit signal ASC_VB. Specifically, when the second driver circuit determines that the voltage of the second active short-circuit signal ASC_VB is within the aforementioned first preset range, the second driver circuit may output a high voltage level to the second IGBT S5 to turn on the second IGBT S5. When the second driver circuit determines that the voltage of the second active short-circuit signal ASC_VB is within the aforementioned second preset range, the second driver circuit may output a low voltage level to the second IGBT S5 to turn off the second IGBT S5.

[0035] The second operational amplifier module is used to generate a third active short-circuit signal output to the third drive circuit based on the first active short-circuit signal and the second ground potential, so that the third drive circuit controls the on and off of the third IGBT corresponding to the third drive circuit according to the third active short-circuit signal, wherein the second ground potential is a reference ground potential of the third drive circuit, and when the first IGBT, the second IGBT and the third IGBT are all turned on, active short circuit of the motor is achieved.

[0036] Optionally, the second operational amplifier module may also be a differential operational amplifier circuit. Specifically, the second operational amplifier module may use the second ground potential GND_WB as its own reference ground potential, and then generate a third active short-circuit signal ASC_WB based on the first active short-circuit signal ASC_UB and the third ground potential GND_UB, outputting it to the third driver circuit. The third driver circuit is configured to determine the voltage level output to the second IGBT S6 based on the third active short-circuit signal ASC_WB. Specifically, when the third driver circuit determines that the voltage of the third active short-circuit signal ASC_WB is within the aforementioned first preset range, the third driver circuit may output a high voltage level to the third IGBT S6 to turn on the third IGBT S6. When the third driver circuit determines that the voltage of the third active short-circuit signal ASC_WB is within the aforementioned second preset range, the third driver circuit may output a low voltage level to the third IGBT S6 to turn off the third IGBT S6.

[0037] It should be noted that, during operation, the aforementioned first, second, and third drive circuits determine the voltage value of the received active short-circuit signal based on their own reference ground potentials. That is, if the reference ground potentials of the various drive circuits are different, the determination results of the various drive circuits for the same active short-circuit signal will also differ. In a high-power converter, the emitter of the actual lower three-bridge IGBT is typically connected to the N-pole of the busbar via copper busbar screws, etc., which are equivalent to a certain amount of stray inductance. Furthermore, in a high-power converter, the significant current changes generated at the moment of switch on and off induce a voltage difference across the stray inductance. Consequently, the reference ground potentials corresponding to the first, second, and third drive circuits differ. Consequently, when the first, second, and third drive circuits receive the same active short-circuit signal, they will arrive at different determination results, which can lead to false triggering of the active short-circuit or failure of the active short-circuit function.

[0038] In an embodiment of the present invention, different active short-circuit signals are output to different drive circuits in the lower three bridges. The control module outputs a first active short-circuit signal to the first drive circuit, so that the first drive circuit controls the on / off of the first IGBT corresponding to the first drive circuit according to the first active short-circuit signal. Then, the first operational amplifier module determines a second active short-circuit signal based on the first active short-circuit signal and the first ground potential, and outputs the second active short-circuit signal to the second drive circuit, so that the second drive circuit controls the on / off of the second IGBT corresponding to the second drive circuit according to the second active short-circuit signal. Furthermore, the second operational amplifier module determines a third active short-circuit signal based on the first active short-circuit signal and the second ground potential, and outputs the third active short-circuit signal to the third drive circuit, so that the third drive circuit controls the on / off of the third IGBT corresponding to the third drive circuit according to the third active short-circuit signal. In this way, when the first IGBT, the second IGBT and the third IGBT are all turned on, active short-circuiting of the motor is achieved. Among them, the first ground potential is the reference ground potential of the second drive circuit, the second ground potential is the reference ground potential of the third drive circuit, and the first drive circuit, the second drive circuit and the third drive circuit in the lower three bridge arms are powered by a backup power supply.

[0039] It is easy to note that in the above process, by directly outputting the first active short-circuit signal to the first drive circuit, then outputting the second active short-circuit signal, which is different from the first active circuit, to the second drive circuit, and outputting the third active short-circuit signal, which is different from the first active circuit, to the third drive circuit, that is, sending three different active circuit signals to different drive circuits in different lower three bridges, the first drive circuit, the second drive circuit, and the third drive circuit can make the same judgment results on the voltage of the received active short-circuit signal based on their own reference ground potentials, effectively achieving anti-interference of the active short-circuit signal and avoiding the phenomenon that the first drive circuit, the second drive circuit, and the third drive circuit reach different judgment results when receiving the same active short-circuit signal due to deviations in the reference ground potential. In addition, because each drive circuit determines the voltage value of the active short-circuit signal based on its corresponding reference ground potential, the second active short-circuit signal is determined based on the first active short-circuit signal and the reference ground potential of the second drive circuit, and the third active short-circuit signal is determined based on the first active short-circuit signal and the reference ground potential of the third drive circuit. This achieves accurate determination of the active short-circuit signal sent to the drive circuit, thereby further improving the signal anti-interference effect.

[0040] It can be seen that the solution provided in the present application achieves the purpose of outputting different active short-circuit signals to different driving circuits in the lower three bridges, thereby realizing the technical effect of anti-interference of the active short-circuit signal, and thus solving the technical problem of signal interference caused by the lower three bridge driving circuits using a common ground power supply and driving the lower three bridge driving circuits by the same active short-circuit signal in the prior art.

[0041] In an optional embodiment, the connection relationship between the three IGBTs in the lower three bridges is specifically described. Specifically, Figure 3 As shown, the collector of the first IGBT S4 in the lower three bridges is connected to the emitter of the fourth IGBT S1 in the upper three bridges. The gate of the first IGBT S4 is connected to the output terminal of the first drive circuit, and the emitter of the first IGBT S4 is connected to the ground terminal of the first drive circuit. That is, the first drive circuit and the emitter of the first IGBT share a common ground, and the reference ground potential of the first drive circuit is the potential at the emitter of the first IGBT S4. This ensures the normal operation of the first IGBT S4.

[0042] like Figure 3As shown, the collector of the second IGBT S5 in the lower three bridges is connected to the emitter of the fifth IGBT S2 in the upper three bridges, the gate of the second IGBT S5 is connected to the output terminal of the second drive circuit, and the emitter of the second IGBT S5 is connected to the ground terminal of the second drive circuit. That is, the second drive circuit and the emitter of the second IGBT share a common ground, and the reference ground potential of the second drive circuit is the potential at the emitter of the second IGBT S5. This ensures the normal operation of the second IGBT S5.

[0043] like Figure 3 As shown, the collector of the third IGBT S6 in the lower three bridges is connected to the emitter of the sixth IGBT S3 in the upper three bridges, the gate of the third IGBT S6 is connected to the output terminal of the third drive circuit, and the emitter of the third IGBT S6 is connected to the ground terminal of the third drive circuit. That is, the third drive circuit and the emitter of the third IGBT share a common ground, and the reference ground potential of the third drive circuit is the potential at the emitter of the third IGBT S6. This ensures the normal operation of the third IGBT S6.

[0044] In an optional embodiment, the first operational amplifier module and the second operational amplifier module are both differential operational amplifier circuits. Optionally, the first input terminal of the first operational amplifier module is connected to the output terminal of the control module via a first resistor, the second input terminal of the first operational amplifier module is connected to the emitter of the first IGBT via a second resistor, and the second input terminal of the first operational amplifier module is connected to the emitter of the second IGBT via a third resistor, the output terminal of the first operational amplifier module is connected to the input terminal of the second drive circuit, and the output terminal of the first operational amplifier module is connected to the first input terminal of the first operational amplifier module via a fourth resistor, and the ground terminal of the first operational amplifier module is connected to the emitter of the second IGBT.

[0045] Among them, Figure 4 As shown, the connection relationship corresponding to the first operational amplifier module is specifically described. Specifically, the first operational amplifier module (ie Figure 4The inverting input terminal of the operational amplifier 8 (i.e., the first input terminal of the first operational amplifier module) is connected to the output terminal of the control module through a first resistor R1, for obtaining a first active short-circuit signal ASC_UB. The non-inverting input terminal of the first operational amplifier module (i.e., the second input terminal of the first operational amplifier module) is connected to the emitter of the first IGBT S4 through a second resistor R2, for obtaining a third ground potential GND_UB. The non-inverting input terminal of the first operational amplifier module is connected to the emitter of the second IGBT S5 through a third resistor R3, and the output terminal of the first operational amplifier module is connected to the inverting input terminal of the first operational amplifier module through a fourth resistor R4. In addition, the ground terminal of the first operational amplifier module is connected to the emitter of the second IGBT S5, that is, the first operational amplifier module, the second drive circuit, and the second IGBT S5 are arranged on a common ground, and the reference ground potential of the first operational amplifier module is the same as the reference ground potential of the second drive circuit.

[0046] Furthermore, the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 can be set equal, so that the operational amplifier gain is 1, thereby ensuring that the difference between the first active short-circuit signal ASC_UB and the third ground potential GND_UB is equal to the difference between the second active short-circuit signal ASC_VB and the first ground potential GND_VB. Furthermore, because the reference ground potential of the first operational amplifier module is set to be the same as the reference ground potential of the second drive circuit, the voltage value of the first active short-circuit signal ASC_UB determined by the first drive circuit based on the third ground potential GND_UB can be equal to the voltage value of the second active short-circuit signal ASC_VB determined by the second drive circuit based on the second ground potential GND_VB. As a result, when the active short-circuit circuit needs to be shorted, the first IGBT S4 and the second IGBT S5 can be simultaneously turned on under the control of the same control module, thereby achieving signal interference immunity for the second active short-circuit signal. Furthermore, by configuring the first operational amplifier module as a differential operational amplifier circuit, the high cost of using isolation chips to achieve signal interference immunity is effectively avoided.

[0047] Optionally, the first input terminal of the second operational amplifier module is connected to the output terminal of the control module through a fifth resistor, the second input terminal of the second operational amplifier module is connected to the emitter of the first IGBT through a sixth resistor, and the second input terminal of the second operational amplifier module is connected to the emitter of the third IGBT through a seventh resistor, and the output terminal of the second operational amplifier module is connected to the first input terminal of the second operational amplifier module through an eighth resistor, and the ground terminal of the second operational amplifier module is connected to the emitter of the third IGBT.

[0048] Among them, Figure 4 As shown, the connection relationship corresponding to the second operational amplifier module is specifically described. Specifically, the second operational amplifier module (ie Figure 4The inverting input terminal of the operational amplifier 9 (i.e., the first input terminal of the second operational amplifier module) is connected to the output terminal of the control module through the fifth resistor R5 for receiving the first active short-circuit signal ASC_UB, and the non-inverting input terminal of the second operational amplifier module (i.e., the second input terminal of the second operational amplifier module) is connected to the emitter of the first IGBT S4 through the sixth resistor R6 for obtaining the third ground potential GND_UB. The non-inverting input terminal of the second operational amplifier module is connected to the emitter of the third IGBT S6 through the seventh resistor R7, and the output terminal of the second operational amplifier module is connected to the inverting input terminal of the second operational amplifier module through the eighth resistor R8. In addition, the ground terminal of the second operational amplifier module is connected to the emitter of the third IGBT S6, that is, the second operational amplifier module, the third drive circuit, and the third IGBT S6 are arranged on a common ground, and the reference ground potential of the second operational amplifier module is the same as the reference ground potential of the third drive circuit.

[0049] Furthermore, the resistance values ​​of the aforementioned fifth resistor R5, sixth resistor R6, seventh resistor R7 and eighth resistor R8 can be set equal to the resistance values ​​of the aforementioned first resistor R1, second resistor R2, third resistor R3 and fourth resistor R4, so that the op amp gain multiplier is 1, thereby ensuring that the difference between the first active short-circuit signal ASC_UB and the third ground potential GND_UB is the same as the difference between the third active short-circuit signal ASC_WB and the second ground potential GND_WB. Furthermore, since the reference ground potential of the second operational amplifier module is set to be the same as the reference ground potential of the third drive circuit, the voltage value of the first active short-circuit signal ASC_UB determined by the first drive circuit based on the third ground potential GND_UB can be made equal to the voltage value of the third active short-circuit signal ASC_WB determined by the third drive circuit based on the second ground potential GND_WB. As a result, when the active short-circuit circuit needs to be actively short-circuited, the first IGBT S4 and the third IGBT S6 can be turned on simultaneously under the control of the same control module, thereby achieving signal interference resistance against the third active short-circuit signal. In addition, by setting the second operational amplifier module as a differential operational amplifier circuit, the high cost of using an isolation chip to achieve signal interference resistance is effectively avoided.

[0050] In an optional embodiment, the backup power supply may also be co-grounded with the first, second, and third drive circuits. However, since co-grounding the first, second, and third drive circuits means that the emitters of the first, second, and third IGBTs are connected, and a certain amount of stray inductance will still be generated between the emitters of the first, second, and third IGBTs, in this case, based on the active short-circuit circuit provided by the present application, the first, second, and third drive circuits may have certain deviations in their determination results of the voltage values ​​of their corresponding active short-circuit signals. However, compared to existing related circuits, they can still achieve a certain degree of signal interference resistance. Furthermore, when the backup power supply only shares a common ground with the first drive circuit, but not with the second and third drive circuits, based on the active short-circuit circuit provided by the present application, the first, second, and third drive circuits can have completely identical determination results of the voltage values ​​of their corresponding active short-circuit signals, thereby achieving better signal interference resistance.

[0051] It can be seen that the solution provided in the present application achieves the purpose of outputting different active short-circuit signals to different driving circuits in the lower three bridges, thereby realizing the technical effect of anti-interference of the active short-circuit signal, and thus solving the technical problem of signal interference caused by the lower three bridge driving circuits using a common ground power supply and driving the lower three bridge driving circuits by the same active short-circuit signal in the prior art.

[0052] Example 2

[0053] According to an embodiment of the present invention, an embodiment of an active short-circuiting method is provided, which is applied to the above-mentioned active short-circuiting circuit. It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system, such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be performed in a different order than shown here.

[0054] Figure 5 is a schematic diagram of an optional active short-circuit method according to an embodiment of the present invention, such as Figure 5 As shown, the method includes the following steps:

[0055] Step S501 : outputting a first active short-circuit signal to a first driving circuit, so that the first driving circuit controls the on / off of a first IGBT corresponding to the first driving circuit according to the first active short-circuit signal.

[0056] In step S501, the active short-circuit circuit in embodiment 1 can be used as the execution body of this embodiment to execute the aforementioned active short-circuit method. Figure 3As shown, the output terminal of the control module is connected to the second input terminal of the first drive circuit, and the control module can output a first active short-circuit signal ASC_UB to the first drive circuit. The first drive circuit is configured to determine the voltage level of the output to the first IGBT S4 based on the first active short-circuit signal ASC_UB. Specifically, when the first drive circuit determines that the voltage of the first active short-circuit signal ASC_UB is within a first preset range, the first drive circuit can output a high voltage level to the first IGBT S4 to turn on the first IGBT S4. When the first drive circuit determines that the voltage of the first active short-circuit signal ASC_UB is within a second preset range, the first drive circuit can output a low voltage level to the first IGBT S4 to turn off the first IGBT S4. The first preset range and the second preset range do not overlap.

[0057] Step S502 , determining a second active short-circuit signal according to the first active short-circuit signal and the first ground potential, and outputting the second active short-circuit signal to the second drive circuit, so that the second drive circuit controls the on and off of the second IGBT corresponding to the second drive circuit according to the second active short-circuit signal.

[0058] In step S502, the first operational amplifier module may use the first ground potential GND_VB as its own reference ground potential, and then generate a second active short-circuit signal ASC_VB based on the first active short-circuit signal ASC_UB and the third ground potential GND_UB, outputting it to the second driver circuit. The third ground potential GND_UB serves as the reference ground potential of the first driver circuit. The second driver circuit is configured to determine the voltage level output to the second IGBT S5 based on the second active short-circuit signal ASC_VB. Specifically, when the second driver circuit determines that the voltage of the second active short-circuit signal ASC_VB is within the first preset range, the second driver circuit may output a high voltage level to the second IGBT S5 to turn on the second IGBT S5. When the second driver circuit determines that the voltage of the second active short-circuit signal ASC_VB is within the second preset range, the second driver circuit may output a low voltage level to the second IGBT S5 to turn off the second IGBT S5.

[0059] Step S503: Determine a third active short-circuit signal based on the first active short-circuit signal and the second ground potential, and output the third active short-circuit signal to the third drive circuit, so that the third drive circuit controls the on and off of the third IGBT corresponding to the third drive circuit according to the third active short-circuit signal. When the first IGBT, the second IGBT and the third IGBT are all turned on, active short circuit of the motor is achieved.

[0060] In step S503, the second operational amplifier module may use the second ground potential GND_WB as its own reference ground potential and then, based on the first active short-circuit signal ASC_UB and the third ground potential GND_UB, generate a third active short-circuit signal ASC_WB, which is output to the third driver circuit. The third driver circuit is configured to determine the voltage level of the signal output to the second IGBT S6 based on the third active short-circuit signal ASC_WB. Specifically, when the third driver circuit determines that the voltage of the third active short-circuit signal ASC_WB is within the first preset range, the third driver circuit may output a high voltage level to the third IGBT S6 to turn on the third IGBT S6. When the third driver circuit determines that the voltage of the third active short-circuit signal ASC_WB is within the second preset range, the third driver circuit may output a low voltage level to the third IGBT S6 to turn off the third IGBT S6.

[0061] Based on the scheme defined in steps S501 to S503 above, it can be seen that in an embodiment of the present invention, different active short-circuit signals are output to different drive circuits in the lower three bridges. A first active short-circuit signal is output to the first drive circuit so that the first drive circuit controls the on / off of a first IGBT corresponding to the first drive circuit according to the first active short-circuit signal. A second active short-circuit signal is then determined based on the first active short-circuit signal and the first ground potential, and the second active short-circuit signal is output to the second drive circuit so that the second drive circuit controls the on / off of a second IGBT corresponding to the second drive circuit according to the second active short-circuit signal. A third active short-circuit signal is determined based on the first active short-circuit signal and the second ground potential, and the third active short-circuit signal is output to the third drive circuit so that the third drive circuit controls the on / off of a third IGBT corresponding to the third drive circuit according to the third active short-circuit signal. Thus, active short-circuiting of the motor is achieved when the first, second, and third IGBTs are all turned on.

[0062] It is easy to note that in the above process, by directly outputting the first active short-circuit signal to the first drive circuit, then outputting the second active short-circuit signal, which is different from the first active circuit, to the second drive circuit, and outputting the third active short-circuit signal, which is different from the first active circuit, to the third drive circuit, that is, sending three different active circuit signals to different drive circuits in different lower three bridges, the first drive circuit, the second drive circuit, and the third drive circuit can make the same judgment results on the voltage of the received active short-circuit signal based on their own reference ground potentials, effectively achieving anti-interference of the active short-circuit signal and avoiding the phenomenon that the first drive circuit, the second drive circuit, and the third drive circuit reach different judgment results when receiving the same active short-circuit signal due to deviations in the reference ground potential. In addition, because each drive circuit determines the voltage value of the active short-circuit signal based on its corresponding reference ground potential, the second active short-circuit signal is determined based on the first active short-circuit signal and the reference ground potential of the second drive circuit, and the third active short-circuit signal is determined based on the first active short-circuit signal and the reference ground potential of the third drive circuit. This achieves accurate determination of the active short-circuit signal sent to the drive circuit, thereby further improving the signal anti-interference effect.

[0063] It can be seen that the solution provided in the present application achieves the purpose of outputting different active short-circuit signals to different driving circuits in the lower three bridges, thereby realizing the technical effect of anti-interference of the active short-circuit signal, and thus solving the technical problem of signal interference caused by the lower three bridge driving circuits using a common ground power supply and driving the lower three bridge driving circuits by the same active short-circuit signal in the prior art.

[0064] In an optional embodiment, the active short-circuit circuit may determine the second active short-circuit signal according to the first active short-circuit signal, a third ground potential, and the first ground potential, wherein the third ground potential is a reference ground potential of the first driving circuit.

[0065] Optionally, the first op amp module may determine the second active short-circuit signal ASC_VB according to the first active short-circuit signal ASC_VB, the third ground potential GND_UB and the first ground potential GND_VB based on a rule that ensures that the difference between the first active short-circuit signal ASC_UB and the third ground potential GND_UB is the same as the difference between the second active short-circuit signal ASC_VB and the first ground potential GND_VB.

[0066] It should be noted that, since the reference ground potential of the first operational amplifier module is set to be the same as the reference ground potential of the second drive circuit, the voltage value of the first active short-circuit signal ASC_UB determined by the first drive circuit based on the third ground potential GND_UB can be equal to the voltage value of the second active short-circuit signal ASC_VB determined by the second drive circuit based on the second ground potential GND_VB. As a result, when the active short-circuit circuit needs to implement active short-circuiting, the first IGBT S4 and the second IGBTS5 can be turned on simultaneously under the control of the same control module, thereby achieving signal interference resistance against the second active short-circuit signal. In addition, by setting the first operational amplifier module as a differential operational amplifier circuit, the high cost of using an isolation chip to implement signal interference resistance is effectively avoided.

[0067] In an optional embodiment, the active short-circuit circuit may determine the third active short-circuit signal according to the first active short-circuit signal, the third ground potential, and the second ground potential.

[0068] Optionally, the second op amp module can determine the third active short-circuit signal ASC_WB according to the first active short-circuit signal ASC_VB, the third ground potential GND_UB and the second ground potential GND_WB based on a rule that ensures that the difference between the first active short-circuit signal ASC_UB and the third ground potential GND_UB is the same as the difference between the third active short-circuit signal ASC_WB and the second ground potential GND_WB.

[0069] It should be noted that, since the reference ground potential of the second operational amplifier module is set to be the same as the reference ground potential of the third drive circuit, the voltage value of the first active short-circuit signal ASC_UB determined by the first drive circuit based on the third ground potential GND_UB can be equal to the voltage value of the third active short-circuit signal ASC_WB determined by the third drive circuit based on the second ground potential GND_WB. As a result, when the active short-circuit circuit needs to implement active short-circuiting, the first IGBT S4 and the third IGBTS6 can be turned on simultaneously under the control of the same control module, thereby achieving signal anti-interference for the third active short-circuit signal. In addition, by setting the second operational amplifier module as a differential operational amplifier circuit, the high cost of using isolation chips to implement signal anti-interference is effectively avoided.

[0070] Example 3

[0071] According to an embodiment of the present invention, a vehicle is further provided, in which the above-mentioned active short-circuit circuit is applied.

[0072] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0073] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0074] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0075] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected to achieve the purpose of the present embodiment according to actual needs.

[0076] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0077] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, etc. Various media that can store program codes.

[0078] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An active short-circuit circuit, comprising a power conversion circuit connected to an input terminal of a motor, wherein the power conversion circuit comprises six bridge arms, and each bridge arm comprises at least an insulated gate bipolar transistor (IGBT) and a drive circuit for controlling the on / off of the IGBT, characterized in that: Also includes: A backup power supply, used to supply power to the first drive circuit, the second drive circuit, and the third drive circuit in the lower three bridge arms, wherein the backup power supply shares a common ground with at least the first drive circuit; a control module, configured to output a first active short-circuit signal to the first drive circuit, so that the first drive circuit controls the on and off of a first IGBT corresponding to the first drive circuit according to the first active short-circuit signal; a first operational amplifier module, configured to generate, based on the first active short-circuit signal and a first ground potential, a second active short-circuit signal output to the second drive circuit, so that the second drive circuit controls the on / off of a second IGBT corresponding to the second drive circuit according to the second active short-circuit signal, wherein the first ground potential is a reference ground potential of the second drive circuit; The second operational amplifier module is used to generate a third active short-circuit signal output to a third drive circuit based on the first active short-circuit signal and the second ground potential, so that the third drive circuit controls the on and off of a third IGBT corresponding to the third drive circuit according to the third active short-circuit signal, wherein the second ground potential is a reference ground potential of the third drive circuit, and when the first IGBT, the second IGBT and the third IGBT are all turned on, active short circuit of the motor is achieved.

2. The circuit according to claim 1, wherein: An output terminal of the first driving circuit is connected to a gate of the first IGBT, and the first driving circuit and an emitter of the first IGBT share a common ground; An output terminal of the second driving circuit is connected to the gate of the second IGBT, and the second driving circuit and the emitter of the second IGBT share a common ground; An output end of the second driving circuit is connected to the gate of the third IGBT, and the third driving circuit and the emitter of the third IGBT share a common ground.

3. The circuit according to claim 2, characterized in that The first operational amplifier module and the second operational amplifier module are both differential operational amplifier circuits.

4. The circuit according to claim 3, characterized in that The first input terminal of the first operational amplifier module is connected to the output terminal of the control module through a first resistor, the second input terminal of the first operational amplifier module is connected to the emitter of the first IGBT through a second resistor, and the second input terminal of the first operational amplifier module is connected to the emitter of the second IGBT through a third resistor, the output terminal of the first operational amplifier module is connected to the input terminal of the second drive circuit, and the output terminal of the first operational amplifier module is connected to the first input terminal of the first operational amplifier module through a fourth resistor, and the ground terminal of the first operational amplifier module is connected to the emitter of the second IGBT.

5. The circuit according to claim 4, characterized in that The first input terminal of the second operational amplifier module is connected to the output terminal of the control module through a fifth resistor, the second input terminal of the second operational amplifier module is connected to the emitter of the first IGBT through a sixth resistor, and the second input terminal of the second operational amplifier module is connected to the emitter of the third IGBT through a seventh resistor, and the output terminal of the second operational amplifier module is connected to the first input terminal of the second operational amplifier module through an eighth resistor, and the ground terminal of the second operational amplifier module is connected to the emitter of the third IGBT.

6. The circuit according to claim 5, characterized in that The resistance values ​​of the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor, the sixth resistor, the seventh resistor, and the eighth resistor are equal.

7. An active short-circuit method, characterized in that: The active short-circuit circuit according to any one of claims 1 to 6 comprises: Outputting a first active short-circuit signal to a first drive circuit, so that the first drive circuit controls the on / off of a first IGBT corresponding to the first drive circuit according to the first active short-circuit signal; Determining a second active short-circuit signal according to the first active short-circuit signal and the first ground potential, and outputting the second active short-circuit signal to a second drive circuit, so that the second drive circuit controls the on and off of a second IGBT corresponding to the second drive circuit according to the second active short-circuit signal; A third active short-circuit signal is determined based on the first active short-circuit signal and the second ground potential, and the third active short-circuit signal is output to a third drive circuit, so that the third drive circuit controls the on and off of a third IGBT corresponding to the third drive circuit according to the third active short-circuit signal, wherein when the first IGBT, the second IGBT and the third IGBT are all turned on, active short circuit of the motor is achieved.

8. The method according to claim 7, characterized in that Determining a second active short-circuit signal according to the first active short-circuit signal and the first ground potential includes: A second active short-circuit signal is determined according to the first active short-circuit signal, a third ground potential, and the first ground potential, wherein the third ground potential is a reference ground potential of the first driving circuit.

9. The method according to claim 7, characterized in that Determining a third active short-circuit signal according to the first active short-circuit signal and the second ground potential includes: A third active short-circuit signal is determined according to the first active short-circuit signal, a third ground potential, and the second ground potential.

10. A vehicle, characterized in that: The vehicle is applied with the active short-circuit circuit according to any one of claims 1 to 6.

Images