Motor controller with short circuit isolation function, power assembly and electric vehicle

Abstract

The embodiment disclosed by the application belongs to the field of new energy vehicles, and particularly relates to a motor controller with a fault isolation function, a power assembly and an electric vehicle. The motor controller comprises an inverter circuit and a control circuit, the inverter circuit comprises three-phase bridge arms, each phase bridge arm comprises an upper bridge arm switch tube and a lower bridge arm switch tube, and the bridge arm midpoint of each phase bridge arm is used for connecting a phase winding of a driving motor through a switch module. The control circuit is used for controlling the closing of the switch module corresponding to each phase bridge arm, and controlling the bridge arm midpoint of each phase bridge arm to output a current to the phase winding of the driving motor. In the process of outputting the current by the inverter circuit, the control circuit controls the switch module corresponding to at least one phase bridge arm to be disconnected in response to the short circuit of the upper bridge arm switch tube or the lower bridge arm switch tube of the at least one phase bridge arm. By using the application, the output torque of the driving motor can be continuously controlled after the short circuit fault of any phase bridge arm in the motor controller, and the driving safety can be improved.

Description

Technical Field

[0001] This application relates to the field of new energy vehicles, and in particular to a motor controller, powertrain, and electric vehicle with short-circuit isolation function. Background Technology

[0002] The motor control unit (MCU) is a component in new energy vehicles used to control the motor. The motor controller is also connected to the power battery and can convert the DC power provided by the power battery into AC power required to drive the motor.

[0003] Motor controllers are typically equipped with a three-phase full-bridge inverter topology. By controlling the on and off of the switching transistors on each bridge arm of the inverter, DC power can be converted into AC power.

[0004] In certain special circumstances (such as overheating of the switching transistor), a short circuit may occur in the switching transistor on the bridge arm. In this case, to avoid damaging the drive motor, it is necessary to control the motor controller to put the drive motor into a safety protection state and stop supplying power to the motor. However, this will also cause the vehicle to lose power, affecting driving safety. Summary of the Invention

[0005] This application provides a motor controller, powertrain, and electric vehicle with short-circuit isolation function, which can improve vehicle driving safety. The corresponding technical solution is as follows:

[0006] In a first aspect, a motor controller with fault isolation function is provided, the motor controller including an inverter circuit and a control circuit, wherein:

[0007] The inverter circuit includes three-phase bridge arms. Each phase bridge arm includes an upper bridge arm switch and a lower bridge arm switch. The midpoint of each phase bridge arm is used to connect to one phase winding of the drive motor through a switching module.

[0008] The control circuit is used to: control the closing of the switch module corresponding to each phase arm, and control the midpoint of the three-phase arm to output three-phase current to the three-phase winding of the drive motor.

[0009] During the process of the inverter circuit outputting three-phase current, the control circuit responds to the short circuit of the upper or lower bridge arm switch of at least one phase bridge arm. Specifically, the control circuit is used to control the switch module corresponding to the at least one phase bridge arm to disconnect.

[0010] In the solution shown in this application, when a short circuit occurs in the upper or lower switch of one phase of the three-phase bridge arm, the control circuit can disconnect the switch module between the midpoint of that phase bridge arm and the drive motor winding. This prevents the short-circuit three-phase current from flowing to the drive motor winding, thus protecting the drive motor. Meanwhile, the midpoints of the remaining two phase bridge arms can still normally output two-phase AC power to the drive motor winding, allowing the drive motor to operate with a single phase, thereby preventing the vehicle from completely losing power and improving driving safety and operational reliability.

[0011] In one possible implementation, the motor controller includes three drive circuits, each for driving the upper and lower bridge arm switches of one phase of the three-phase bridge arm, each drive circuit for receiving power from one power source, and different drive circuits for receiving different power sources.

[0012] In the scheme shown in this application, the drive current of the three-phase bridge arm of the inverter circuit is supplied by three power supplies respectively. This way, even if a short circuit occurs in any one phase bridge arm, causing the corresponding power supply to short-circuit, the other two power supplies can still normally supply power to the remaining two un-short-circuited bridge arms. This allows for normal control of the remaining two bridge arms to provide two-phase AC power to the drive motor, thereby ensuring the rotation of the drive motor and improving vehicle driving safety.

[0013] In one feasible approach, during the output of three-phase current by the inverter circuit, the control circuit responds to a short circuit in the upper or lower bridge arm switch of at least one phase bridge arm, and the control circuit is used to control the power supply corresponding to at least one phase bridge arm to stop supplying power.

[0014] In the solution shown in this application, after a short circuit occurs in the switching transistor of one phase bridge arm in the inverter circuit, the control circuit stops supplying power to that phase bridge arm, which can turn off the non-short-circuited switching transistor. This can prevent the non-short-circuited switching transistor from forming a path with the short-circuited switching transistor when it is conducting, thereby avoiding short-circuiting the drive motor and improving vehicle driving safety.

[0015] In one feasible manner, during the process of the inverter circuit outputting three-phase current, the control circuit responds to a short circuit in the upper or lower bridge arm switch of at least one phase arm by outputting a turn-off signal, which controls the turn-off of the upper and lower bridge arm switches of at least one phase arm.

[0016] In the solution shown in this application, after a short circuit occurs in the switching transistor of one phase bridge arm in the inverter circuit, the control circuit outputs a turn-off signal to the switching transistor of that phase bridge arm, causing the non-short-circuited switching transistor to turn off. This can prevent the non-short-circuited switching transistor from forming a path with the short-circuited switching transistor when it is conducting, thereby avoiding short-circuiting the drive motor and improving vehicle driving safety.

[0017] In one feasible approach, during the process of the inverter circuit outputting three-phase current, the control circuit is configured to: first control the un-short-circuited upper or lower bridge arm switch in at least one phase arm to disconnect, and then control the corresponding switch module of at least one phase arm to disconnect.

[0018] In the solution shown in this application, if a switch in one phase arm of the inverter circuit is short-circuited, the control circuit can first turn off the un-short-circuited switches in that phase arm to prevent both the upper and lower arm switches of that phase arm from conducting, which would cause a short circuit in the drive motor. Then, by controlling the corresponding switch module of at least one phase arm to disconnect, the short-circuit three-phase current of that phase arm can be prevented from flowing to the drive motor windings, thus protecting the drive motor.

[0019] In one possible implementation, during the process of the inverter circuit outputting the three-phase current, the control circuit responds to the current through the upper or lower bridge arm switch of at least one phase bridge arm being greater than a current threshold. Specifically, the control circuit controls the switching module corresponding to at least one phase bridge arm to disconnect.

[0020] In the solution shown in this application, the control circuit can determine that there is a short circuit in the three-phase current of the upper or lower bridge arm switch of at least one phase bridge arm after detecting that the three-phase current of the upper or lower bridge arm switch of at least one phase bridge arm is greater than the current threshold. Then, it controls the corresponding switch module of at least one phase bridge arm to open, so as to prevent the short-circuit three-phase current of that phase bridge arm from flowing to the winding of the drive motor, thereby protecting the drive motor.

[0021] In one possible implementation, during the process of the inverter circuit outputting three-phase current, the control circuit responds to the current of the upper or lower bridge arm switch of at least one phase arm being greater than a current threshold. Specifically, the control circuit is used to control the inverter circuit to be in a safety protection state.

[0022] After the control circuit controls the inverter circuit to be in a safe protection state for a preset time, the control circuit is specifically used to control both the upper and lower bridge arm switches of the three-phase bridge arm to be turned off.

[0023] The control circuit responds to a greater than zero current through the upper or lower bridge arm switch of at least one phase bridge arm. Specifically, the control circuit controls the switching module corresponding to at least one phase bridge arm to disconnect.

[0024] Safety protection states include active short circuit (ASC) state or full shut-off (SPO) state.

[0025] In the scheme shown in this application, after the control circuit determines that the current of the upper or lower bridge arm switch of at least one phase bridge arm is greater than the current threshold, it can further verify whether there is a short circuit in the upper or lower bridge arm switch of at least one phase bridge arm. Before verification, controlling the drive motor to enter a safety protection state for a preset time can reduce the back electromotive force generated by the drive motor, thereby protecting the components in the inverter circuit. After turning off the upper and lower bridge arm switches in the three-phase bridge arm, if the three-phase current at the midpoint of at least one phase bridge arm is greater than zero or greater than the current threshold, it can be determined that there is a short circuit in the upper or lower bridge arm switch of that at least one phase bridge arm. This allows the corresponding switch module of at least one phase bridge arm to be disconnected, preventing the short-circuit three-phase current of that phase bridge arm from flowing to the windings of the drive motor, thus protecting the drive motor.

[0026] Safety protection states include Active Short Circuit (ASC) and Switching Pulse Off (SPO) states. Active Short Circuit (ASC) refers to the situation where all upper or lower bridge arm switches in each phase of the three-phase bridge arm are turned on, forming a closed circuit between the three-phase windings of the drive motor and the three conducting upper or lower bridge arm switches and the three-phase windings. Entering the Active Short Circuit (ASC) state isolates the motor controller, drive motor, and power battery, ensuring high-voltage safety for the entire vehicle. It also allows the drive motor to generate reverse torque for gradual braking. Furthermore, entering the Active Short Circuit (ASC) state prevents the drive motor from generating excessive back electromotive force that could damage the power battery, bus capacitors, and other components.

[0027] The fully shut-off SPO state refers to the fact that the upper and lower bridge arm switches of each phase of the three-phase bridge arm are turned off, thereby isolating the motor controller, drive motor and power battery.

[0028] In one possible implementation, during the process of the inverter circuit outputting the three-phase current, the control circuit is specifically configured to: control the drive motor to enter a safety protection state in response to the three-phase current through the upper or lower bridge arm switch of at least one phase arm of the three-phase bridge arm being greater than a current threshold and the speed of the drive motor being greater than a preset speed.

[0029] In the scheme shown in this application, before the control circuit verifies again whether there is a short circuit in the upper or lower bridge arm switch of at least one phase bridge arm, if the speed of the drive motor is greater than the preset speed, the inverter circuit needs to be controlled to be in a safety protection state to reduce the back electromotive force generated by the drive motor and protect the components in the inverter circuit.

[0030] In one possible implementation, the motor controller receives a torque signal and controls the drive motor to output the torque indicated by the torque signal. During the output of three-phase current from the inverter circuit, the control circuit specifically controls at least one phase arm's corresponding switching module to disconnect in response to a short circuit in the upper or lower switching transistor of one phase arm of the three-phase bridge arm. In response to the disconnection of the switching module corresponding to that phase arm, the controller controls the midpoint of the other two phase arms to output two-phase AC current. This two-phase AC current is used to drive the drive motor to output torque, and the average value of the torque output by the drive motor driven by the two-phase AC current is less than the torque value indicated by the torque signal.

[0031] In the scheme shown in this application, the control circuit can control the remaining two bridge arms without short-circuit faults to output two-phase AC power to the windings of the drive motor. This output two-phase AC power can drive the vehicle drive motor to output torque, ensuring the vehicle does not lose power. However, changing the drive motor from three-phase AC to two-phase AC will prevent one phase of the drive motor winding from generating torque normally. Therefore, after a short-circuit fault occurs in a bridge arm, the average value of the torque output by the motor controller driving that drive motor may be less than the torque value indicated by the torque signal.

[0032] In one feasible approach, during the process of the inverter circuit outputting two-phase AC power, the motor controller is used to: control the speed of the drive motor to be less than a preset speed value.

[0033] In the solution presented in this application, to improve the safety of the motor controller driving the vehicle's drive motor output torque via two-phase AC power, the rotational speed can be controlled to be lower than a preset speed value. The preset speed value can be set by a technician based on the performance of the drive motor. When the drive motor's speed is lower than this preset speed value, torque can be safely output to the vehicle under the drive of two-phase AC power.

[0034] In one feasible approach, during the process of the inverter circuit outputting two-phase AC power, the control circuit responds to a short circuit in either the upper or lower bridge arm switch of either of the two-phase bridge arms, and controls the drive motor to enter a safety protection state.

[0035] In the solution shown in this application, if a short circuit fault occurs again in one of the two bridge arms of the output two-phase AC power from the inverter circuit to the drive motor, the drive motor can be controlled to enter a safety protection state to ensure driving safety.

[0036] In one possible implementation, during the process of the inverter circuit outputting two-phase AC power, the control circuit is configured to: in response to the three-phase current through the upper or lower bridge arm switch of one of the two-phase bridge arms being greater than a current threshold, control the switch module corresponding to one of the two-phase bridge arms to disconnect.

[0037] In the scheme shown in this application, if a short-circuit fault occurs again in one of the two phase bridge arms of the output two-phase AC power from the inverter circuit to the drive motor, the switching module connected to the bridge arm with the short-circuit fault can be controlled to disconnect. In this way, the short-circuit three-phase current of that bridge arm will not flow to the windings of the drive motor, thus protecting the drive motor.

[0038] In a second aspect, a powertrain is provided, the powertrain including a drive motor and a motor controller as described in the first aspect and / or any of the possible implementations of the first aspect, the motor controller being configured to receive a torque signal and control the drive motor to output a torque indicated by the torque signal.

[0039] In one possible implementation, the powertrain includes a resolver sensor and a current sensor. The resolver sensor is used to detect the rotational speed of the drive motor, and the current sensor is used to detect the three-phase current value of the drive motor. The motor controller is used to receive the rotational speed signal from the resolver sensor and the three-phase current signal from the current sensor. The rotational speed signal is used to indicate the rotational speed of the drive motor, and the three-phase current signal is used to indicate the three-phase current value of the drive motor.

[0040] The beneficial effects of the powertrain provided in the second aspect of this application are as described in the beneficial effects of the motor controller provided in the first aspect of this application, and will not be repeated here.

[0041] Thirdly, an electric vehicle is provided, which includes a powertrain, a vehicle controller, and a power battery as described in the second aspect above, wherein the power battery supplies power to the powertrain and the vehicle controller sends torque signals to the motor controller.

[0042] The beneficial effects of the electric vehicle provided in the third aspect of this application are as described in the beneficial effects of the motor controller provided in the first aspect of this application, and will not be repeated here. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of a motor controller provided in an embodiment of this application;

[0044] Figure 2 This is a schematic diagram of the structure of a motor controller provided in an embodiment of this application;

[0045] Figure 3 This is a schematic diagram of the structure of a motor controller provided in an embodiment of this application;

[0046] Figure 4 This is a schematic diagram of the structure of a powertrain provided in an embodiment of this application;

[0047] Figure 5 This is a structural schematic diagram of an electric vehicle provided in an embodiment of this application. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0049] The Motor Control Unit (MCU) is a component in new energy vehicles used to control the drive motor. The MCU is also connected to the power battery, converting the direct current (DC) supplied by the battery into alternating current (AC) required for the drive motor to operate. The MCU typically includes a three-phase full-bridge inverter. By controlling the switching on and off of the transistors on each bridge arm of the inverter, the DC to AC conversion is achieved.

[0050] In certain special circumstances (such as overheating of the switching transistor), a short circuit may occur in the switching transistor on the bridge arm. In this case, to avoid damaging the drive motor, it is necessary to control the motor controller to immediately put the drive motor into a safety protection state and stop supplying power to the motor. However, this will also cause the vehicle to lose power, affecting driving safety.

[0051] This application provides a motor controller with fault isolation function. When a short circuit occurs in the switching transistor of any phase arm of the inverter, it disconnects the AC output of that phase arm to the windings of the drive motor, and can output two-phase AC power to the windings of the drive motor through the remaining two phase arms to drive the motor to rotate. In this way, the vehicle will not lose power after a short circuit occurs in the switching transistor of any phase arm of the inverter, thus ensuring vehicle driving safety.

[0052] Figure 1 This is a schematic diagram of the structure of a motor controller 01 with fault isolation function provided in an embodiment of this application. Figure 1 As shown, the motor controller 01 includes an inverter circuit 1 and a control circuit 2.

[0053] The inverter circuit 1 includes three-phase bridge arms 11. Each phase bridge arm 11 includes an upper bridge arm switch 111 and a lower bridge arm switch 112. The midpoint 113 of each phase bridge arm 11 is used to connect to one phase winding of the drive motor 02 through a switch module 114. The control terminals of the upper bridge arm switch 111, the lower bridge arm switch 112, and the switch module 114 of each phase bridge arm 11 can all be electrically connected to the control circuit 2. The control circuit 2 can control the closing and closing of each upper bridge arm switch 111, each lower bridge arm switch 112, and each switch module 114.

[0054] Under normal operating conditions of the motor controller 01, that is, when there are no short-circuited switching transistors in the inverter circuit 1, the control circuit 2 controls the closing of the switching module 114 corresponding to each phase bridge arm 11, and controls the midpoint 113 of the three-phase bridge arm 11 to output three-phase current to the three-phase windings of the drive motor 02 so that the drive motor 02 can rotate normally.

[0055] During the normal output of three-phase current from inverter circuit 1 to drive motor 02, control circuit 2 is specifically used to control the switching module 114 corresponding to at least one phase bridge arm 11 to disconnect in response to a short circuit in the upper bridge arm switch tube 111 or the lower bridge arm switch tube 112 of at least one phase bridge arm 11.

[0056] Thus, when a short circuit occurs in the upper arm switch 111 or the lower arm switch 112 of one of the three-phase bridge arms 11, the control circuit 2 can disconnect the switch module 114 between the midpoint 113 of that phase bridge arm 11 and the drive motor 02. The short-circuit current of that phase bridge arm 11 will not flow to the windings of the drive motor 02, thus protecting the drive motor 02. Meanwhile, the midpoints 113 of the remaining two phase bridge arms 11 can continue to output two-phase AC power to the windings of the drive motor 02, allowing the drive motor 02 to operate with a single phase. This prevents the vehicle equipped with the motor controller 01 from completely losing power, improving vehicle safety.

[0057] In the motor controller 01 shown in this application, the upper bridge arm switch 111, the lower bridge arm switch 112, and the switching module 114 can be semiconductor devices, such as insulated-gate bipolar transistors (IGBTs), silicon carbide (SiC), etc. Each phase bridge arm 11 can be divided into an upper bridge arm and a lower bridge arm through the bridge arm midpoint 113. Both the upper and lower bridge arms include power modules. The power module located in the upper bridge arm includes the upper bridge arm switch 111, and the power module located in the lower bridge arm includes the lower bridge arm switch 112. In addition to including the upper bridge arm switch 111 or the lower bridge arm switch 112, the power module may also include a detection module (…). Figure 1 (Not shown in the image), such as temperature detection module, short circuit detection module, etc.

[0058] The short-circuit detection module in each power module can be connected in series with the upper arm switch 111 or the lower arm switch 112 of the same power module, and can detect the current value through the upper arm switch 111 or the lower arm switch 112. When the short-circuit detection module detects that the current through the upper arm switch 111 or the lower arm switch 112 is greater than the set current threshold, it can send a fault signal to the control circuit.

[0059] In one example, control circuit 1, in response to a current exceeding a current threshold in the upper arm switch 111 or lower arm switch 112 of at least one phase arm 11 of the three-phase bridge arm 11, controls the switch module 114 corresponding to at least one phase arm 11 to disconnect. That is, after receiving a fault signal from the short-circuit detection module in any power module, control circuit 1 can determine that a short circuit has occurred in the switch of that power module, and then control the switch module 114 connected to the bridge arm 11 containing that power module to disconnect, so that the midpoint of the remaining two phase arms 11 continues to output two-phase AC power to the windings of the drive motor 02.

[0060] In one example, during the normal output of three-phase current from the three-phase bridge arm 11 of the inverter circuit 1 to the drive circuit, if the upper bridge arm switch 111 or the lower bridge arm switch 112 of at least one phase bridge arm 11 is short-circuited, the control circuit 2 is used to first control the upper bridge arm switch 111 or the lower bridge arm switch 112 of at least one phase bridge arm 11 that is not short-circuited to disconnect, and then control the corresponding switch module 114 of at least one phase bridge arm 11 to disconnect.

[0061] In implementation, if a short circuit occurs in the switching transistor of one phase arm 11 of the inverter circuit 1, the control circuit 2 can first turn off the un-short-circuited switching transistor in that phase arm 11 to prevent both the upper and lower bridge arm switching transistors of that phase arm 11 from being turned on. This prevents the DC power input to the inverter circuit 1 from flowing through that phase arm 11, thus preventing the drive motor 02 from losing power. After turning off the un-short-circuited switching transistor in that phase arm 11, the control circuit 2 can then control the corresponding switching module of at least one phase arm to disconnect, thereby preventing the short-circuit current of that phase arm from flowing to the windings of the drive motor 02 and protecting the drive motor 02.

[0062] Figure 2 This is a schematic diagram of the structure of a motor controller 01 with fault isolation function provided in an embodiment of this application. Figure 2 As shown, the motor controller 01 includes three power supplies. The upper bridge arm switch 111 and the lower bridge arm switch 112 included in the three-phase bridge arm 11 of the inverter circuit 1 can be driven by three drive circuits 3 respectively, and these three drive circuits 3 can be powered by three power supplies respectively. These three power supplies can be three independent power supplies, or they can be three power supplies implemented by isolated power supplies.

[0063] Each drive circuit 3 can be electrically connected to two power modules on one bridge arm 11, and can be used to drive the upper bridge arm switch 111 and lower bridge arm switch 112 included in the power module, that is, to provide the voltage difference required for the switch in the power module to conduct. In addition, the drive circuit 3 can also be electrically connected to the detection module in the corresponding power module, and can be used to receive signals sent by the detection module, such as receiving the detection signal sampled by the temperature detection module, receiving the fault signal sent by the short circuit detection module, etc. The power supply of each drive circuit 3 is independent of each other. For example, each drive circuit 3 can be isolated by an isolation power supply. That is to say, if one drive circuit 3 in the motor controller 01 malfunctions (such as being short-circuited), it will not affect the driving and control of the switch on other phase bridge arms 11 by other drive circuits 3.

[0064] exist Figure 2 The motor controller 01 shown has an upper bridge arm switch 111 and a lower bridge arm switch 112 in one phase receiving power from the same power source. Therefore, if either the upper bridge arm switch 111 or the lower bridge arm switch 112 in one phase is short-circuited, the short-circuited switch can short-circuit the power supply to it. This short-circuit prevents the power supply to the corresponding drive circuit 3 from functioning properly, thus preventing the drive circuit from driving the other un-short-circuited switch to close. In other words, when either the upper bridge arm switch 111 or the lower bridge arm switch 112 in one phase is short-circuited, the other un-short-circuited switch 112 or the upper bridge arm switch 111 can enter a turned-off state, preventing the DC power input to the inverter circuit 1 from flowing directly through that phase 11, thereby avoiding power loss for the drive motor 02.

[0065] Figure 3 This is a schematic diagram of the structure of a motor controller 01 with fault isolation function provided in an embodiment of this application. Figure 3 As shown, the upper bridge arm switch 111 included in each phase bridge arm 11 of the inverter circuit 1 can be driven by the upper bridge arm drive circuit 31, and the lower bridge arm switch 112 included in each phase bridge arm 11 can be driven by the lower bridge arm drive circuit 32. These six drive circuits can be powered by six different power supplies. Figure 3 (Not shown in the image). These six power supplies can be six independent power supplies, or they can be six power supplies implemented by isolated power supplies.

[0066] exist Figure 3 The motor controller 01 shown has an upper bridge arm switch 111 and a lower bridge arm switch 112 in each phase bridge arm that are powered by a power source. Therefore, if the upper bridge arm switch 111 or the lower bridge arm switch 112 in a phase bridge arm is short-circuited, the short-circuited switch will not affect the drive and control of the un-short-circuited switch in the same phase bridge arm 11.

[0067] Therefore, the process by which control circuit 2 controls the disconnection of the non-short-circuited switching transistors in the bridge arm 11 experiencing a short-circuit fault may include: in response to a short circuit in the upper bridge arm switching transistor 111 or the lower bridge arm switching transistor 112 of at least one phase bridge arm 11, control circuit 2 outputs a turn-off signal to the upper bridge arm drive circuit 31 and the lower bridge arm drive circuit 32 corresponding to the upper bridge arm switching transistor 111 and the lower bridge arm switching transistor 112 of that phase bridge arm, respectively. Upon receiving the turn-off signal, the upper bridge arm drive circuit 31 and the lower bridge arm drive circuit 32 can drive the corresponding upper bridge arm switching transistor 111 and lower bridge arm switching transistor 112 to turn off. Since the turn-off of the upper bridge arm switching transistor 111 and the lower bridge arm switching transistor 112 involves a short circuit preventing normal turn-off, the non-short-circuited switching transistors can also be turned off.

[0068] In one feasible approach, for Figure 2 and Figure 3 The motor controller 01 shown, in which the control circuit 2 controls the disconnection of the non-short-circuited switching transistors in the bridge arm 11 experiencing a short-circuit fault, may include: in response to a short circuit in the upper bridge arm switching transistor 111 or the lower bridge arm switching transistor 112 of at least one phase bridge arm 11, the control circuit 2 controls the power supply corresponding to at least one phase bridge arm 11 to stop supplying power. That is, when the control circuit 2 receives a fault signal sent by the short-circuit detection module in a phase bridge arm 11, it can control the power supply of that phase bridge arm 11 to stop supplying power to the corresponding drive circuit 3 (or upper bridge arm drive circuit 31 and lower bridge arm drive circuit 32), thereby controlling the disconnection of the non-short-circuited upper bridge arm switching transistor 111 or lower bridge arm switching transistor 112 in that phase bridge arm 11.

[0069] To improve the accuracy of detecting short circuits in the switching transistors of bridge arm 11, this application embodiment also provides a method for determining bridge arm anomalies, including:

[0070] Step S1: In response to the current through the upper bridge arm switch 111 or the lower bridge arm switch 112 of at least one phase bridge arm 11 of the three-phase bridge arm 11 being greater than the current threshold, the control circuit 2 controls the drive motor 02 to enter the safety protection state.

[0071] If the current in the upper arm switch 111 or lower arm switch 112 of at least one phase arm 11 of the three-phase bridge arm 11 exceeds the current threshold, a fault signal can be triggered by the short-circuit detection module in the corresponding power module to send a fault signal to the control circuit 2. To avoid false alarms and improve the accuracy of the control circuit 2 in determining that at least one phase arm 11 has a short-circuit fault, the control circuit 2 can verify the existence of a short circuit in the inverter circuit 1 again. That is, it can turn off the upper arm switch 111 or lower arm switch 112 of each phase arm 11 in the inverter circuit 1. If there is a short circuit in the upper arm switch 111 or lower arm switch 112 of one phase arm 11, a current flow can be detected at the midpoint 113 of that phase arm 11, or a current exceeding the current threshold can be detected.

[0072] When the drive motor 02 operates at a high speed, it generates a back electromotive force (EMF) greater than the input voltage of the inverter circuit 1. If the switches in the inverter circuit 1 are directly turned off at this time, the back EMF generated by the drive motor 02 will be applied to the inverter circuit 1, potentially damaging some components of the motor controller 01. Therefore, before turning off the switches in the inverter circuit 1, the control circuit 2 first controls the state of each phase bridge arm 11 in the inverter circuit 1 to put the drive motor 02 into a safety protection state. Once the speed of the drive motor 02 decreases to a level where its generated back EMF is less than the input voltage of the inverter circuit 1, the control circuit 2 can then turn off the switches in the inverter circuit 1.

[0073] The process by which control circuit 2 controls drive motor 02 to enter a safety protection state may include:

[0074] In one scenario, after the control circuit 2 receives a fault signal corresponding to the upper bridge arm switch 111 in any bridge arm 11, the control circuit 2 can control the upper bridge arm switch 111 of each phase bridge arm 11 to close and control the lower bridge arm switch 112 of each phase bridge arm 11 to open, thereby causing the drive motor 02 to enter a safety protection state. In the safety protection state, the drive motor 02 can release the generated back electromotive force through the upper bridge arm in each phase bridge arm 11.

[0075] In another scenario, after the control circuit 2 receives a fault signal corresponding to the lower bridge arm switch 112 in any bridge arm 11, the control circuit 2 can control the lower bridge arm switch 111 of each phase bridge arm 11 to close and control the upper bridge arm switch 111 of each phase bridge arm 11 to open, thereby putting the drive motor 02 into a safety protection state. In the safety protection state, the drive motor 02 can release the generated back electromotive force through the lower bridge arm in each phase bridge arm 11.

[0076] Safety protection states include Active Short Circuit (ASC) and Switching Pulse Off (SPO) states. Active Short Circuit (ASC) refers to the state where all upper or lower bridge arm switches of each phase of the three-phase bridge arm 11 are turned on, forming a closed loop between the three-phase windings of the drive motor 02 and the three upper or lower bridge arm switches in the on state. When the motor controller 011 enters the Active Short Circuit (ASC) state, it isolates the motor controller 01, drive motor 02, and power battery 04, ensuring the high-voltage safety of the entire vehicle. It also allows the drive motor 02 to generate reverse torque for slow braking. Simultaneously, the active short circuit (ASC) state prevents the drive motor 02 from generating excessive back electromotive force that could damage the power battery 04, bus capacitors, and other components.

[0077] The fully shut-off SPO state refers to the fact that the upper and lower bridge arm switches of each phase of the three-phase bridge arm 11 are all turned off, thereby isolating the motor controller 01, the drive motor 02, and the power battery 04.

[0078] Furthermore, since the vehicle is traveling at low speed when the short-circuit detection module in the power module sends a fault signal to the control circuit 2, meaning the drive motor 02 rotates at a lower speed, the generated back electromotive force (EMF) may be less than the input voltage of the inverter circuit 1. Therefore, another implementation of step S1 could be that the control circuit 2 responds to the current through the upper bridge arm switch 111 or the lower bridge arm switch 112 of at least one phase of the three-phase bridge arm 11 exceeding a current threshold and the rotational speed of the drive motor 02 exceeding a preset speed, by controlling the drive motor 02 to enter a safety protection state. Here, the back EMF generated by the drive motor 02 is positively correlated with the rotational speed of the drive motor 02. The preset rotational speed can be set by the back EMF generated by the drive motor 02; that is, when the rotational speed of the drive motor 02 exceeds the preset speed, the back EMF generated by the drive motor 02 is greater than the input voltage of the inverter circuit 1.

[0079] If the control circuit 2 responds to the current through the upper bridge arm switch 111 or the lower bridge arm switch 112 of at least one phase of the three-phase bridge arm 11 being greater than the current threshold and the speed of the drive motor 02 being less than or equal to the preset speed, then it can directly control both the upper bridge arm switch 111 and the lower bridge arm switch 112 of the three-phase bridge arm 11 to be turned off, and execute step S3.

[0080] Step S2: After the control circuit controls the drive motor 02 to enter the safety protection state for a preset time, the control circuit 2 controls the upper bridge arm switch 111 and the lower bridge arm switch 112 of the three-phase bridge arm 11 to be turned off.

[0081] The preset duration can be set by technicians. The control circuit 2 controls the drive motor 02 to enter a safety protection state, indicating that the drive motor 02 has a high speed and generates a large back electromotive force. Therefore, after waiting for the vehicle to coast for the preset duration to reduce the speed of the drive motor 02, the upper bridge arm switch 111 and the lower bridge arm switch 112 of the three-phase bridge arm 11 are turned off, thereby preventing the components in the motor controller 01 from being damaged by the back electromotive force generated by the drive motor 02.

[0082] Alternatively, another implementation of step S2 could be that the control circuit 2, in response to the speed of the drive motor 02 being less than or equal to a preset speed, controls both the upper bridge arm switch 111 and the lower bridge arm switch 112 of the three-phase bridge arm 11 to be turned off.

[0083] Alternatively, another implementation of step S2 could be that the control circuit 2, in response to the back electromotive force generated by the drive motor 02 being less than or equal to the input voltage of the inverter circuit 1, controls both the upper bridge arm switch 111 and the lower bridge arm switch 112 of the three-phase bridge arm 11 to be turned off.

[0084] After the control circuit 2 controls the drive motor 02 to enter the safety protection state, the control circuit 2 can periodically detect the speed of the drive motor 02 or the back electromotive force generated by the drive motor 02. After determining that the speed of the drive motor 02 is less than or equal to the preset speed, or the back electromotive force generated by the drive motor 02 is less than or equal to the input voltage of the inverter circuit 1, the control circuit 2 controls the upper bridge arm switch 111 and the lower bridge arm switch 112 of the three-phase bridge arm 11 to be turned off.

[0085] Step S3: In response to the current through the upper bridge arm switch 111 or the lower bridge arm switch 112 of at least one phase bridge arm 11 being greater than zero, the control circuit 2 controls the switch module 114 corresponding to at least one phase bridge arm 11 to disconnect.

[0086] After the upper bridge arm switch 111 and the lower bridge arm switch 112 controlling the three-phase bridge arm 11 are both turned off, if there is no bridge arm 11 with a short circuit fault among the three-phase bridge arms 11, then there should be no current flowing through the bridge arm midpoint 113 of each phase bridge arm 11, or no large current flowing through it. Therefore, a module can be set in the motor controller 01 to detect the magnitude of the current passing through the midpoint 113 of each bridge arm. If current is detected flowing through any bridge arm midpoint 113, or if the detected current is greater than a preset threshold, then it can be determined that the bridge arm 11 to which that bridge arm midpoint 113 belongs does indeed have a short circuit fault.

[0087] Once the control circuit 2 determines that a short-circuit fault exists in one of the three-phase bridge arms 11, the switch module 114 connected to that bridge arm 11 can be disconnected. This prevents the short-circuit current from flowing to the windings of the drive motor 02, thus protecting the drive motor 02. Meanwhile, the midpoint 113 of the remaining two-phase bridge arms 11 continues to output two-phase AC power to the windings of the drive motor 02, allowing the drive motor 02 to operate with a single phase. This prevents the vehicle equipped with the motor controller 01 from completely losing power, improving vehicle safety.

[0088] The motor controller 01 provided in this application can be used to receive torque signals sent by the vehicle controller 05 and control the drive motor 02 to output the torque indicated by the torque signal.

[0089] During the normal operation of inverter circuit 1, which outputs three-phase current to drive motor 02 through three-phase bridge arms 11, control circuit 2 is specifically used to: in response to a short circuit in the upper bridge arm switch 111 or lower bridge arm switch 112 of one phase bridge arm 11, control the switching module 114 corresponding to at least one phase bridge arm 11 to disconnect. In response to the disconnection of the switching module 114 corresponding to one phase bridge arm 11, control the midpoint 113 of the other two phase bridge arms 11 to output two-phase AC power. This two-phase AC power is used to drive the drive motor 02 to output torque. The average value of the torque output by the drive motor 02 driven by the two-phase AC power is less than the torque value indicated by the torque signal.

[0090] In this application, after a short-circuit fault occurs in bridge arm 11, the control circuit 2 of the motor controller 01 can control the switch module 114 corresponding to the short-circuit faulted bridge arm 11 to disconnect. Then, it controls the midpoint 113 of the remaining two-phase bridge arms 11 to output two-phase AC power to the windings of the drive motor 02. This output two-phase AC power can drive the vehicle drive motor 02 to output torque, ensuring the vehicle does not lose power. The drive motor 02, which drives the vehicle, is changed from three-phase AC to two-phase AC, meaning one phase winding of the drive motor 02 cannot generate torque normally. Therefore, after a short-circuit fault occurs in bridge arm 11, the average torque output by the motor controller 01 driving the drive motor 02 is less than the torque value indicated by the torque signal.

[0091] Furthermore, to further ensure safe vehicle operation, during the process of control circuit 2 controlling the remaining non-short-circuit-faulted bridge arm 11 to output two-phase AC power to drive motor 02, control circuit 2 can control the speed of drive motor 02 to be lower than a preset speed value, thereby ensuring the normal rotation of drive motor 02 and preventing drive motor 02 malfunction. This preset speed value can be set by technicians according to the performance of drive motor 02. When the speed of drive motor 02 is lower than this preset speed value, it can safely output torque to the vehicle under the drive of two-phase AC power.

[0092] In the process of the motor controller 01 providing two-phase AC power to the drive motor 02, if a short-circuit fault occurs again in the remaining bridge arm 11 that has not experienced a short-circuit fault, the corresponding processing may include: the control circuit 2 is used to control the drive motor 02 to enter a safety protection state in response to a short circuit in either the upper bridge arm switch tube 111 or the lower bridge arm switch tube 112 of any of the two bridge arms 11.

[0093] In practice, if a short-circuit fault occurs again in one of the remaining bridge arms 11 that have not yet experienced a short circuit, the drive motor 02 can be controlled to re-enter the safety protection state. The process of re-entering the safety protection state by controlling the drive motor 02 may include:

[0094] In one scenario, if the control circuit 2 determines that among the remaining two-phase bridge arms 11 that supply two-phase AC power to the drive motor 02, a bridge arm 11 with a short-circuit fault has reappeared, and determines that the upper bridge arm switch 111 of the bridge arm 11 with the short-circuit fault is short-circuited, then the control circuit 2 controls the upper bridge arm switch 111 of the last bridge arm 11 that has not experienced a short-circuit fault to close and the lower bridge arm switch 112 to open, so that the drive motor 02 enters a safety protection state.

[0095] In another scenario, if the control circuit 2 determines that a short-circuit fault has occurred again among the remaining two-phase bridge arms 11 that supply two-phase AC power to the drive motor 02, and determines that the lower bridge arm switch 112 of the bridge arm 11 with the short-circuit fault is short-circuited, then the control circuit 2 controls the lower bridge arm switch 112 of the last bridge arm 11 that has not experienced a short-circuit fault to close and the upper bridge arm switch 111 to open, so that the drive motor 02 enters a safety protection state.

[0096] In addition, if a short-circuit fault occurs again in the remaining bridge arm 11 that has not experienced a short-circuit fault, the control circuit 2 controls the switch module 114 corresponding to the one phase bridge arm 11 to disconnect in response to the current through the upper bridge arm switch tube 111 or the lower bridge arm switch tube 112 of one phase bridge arm 11 being greater than the current threshold.

[0097] During the process of inverter circuit 1 outputting two-phase AC power to drive motor 02, if a short-circuit fault occurs again in one of the two-phase bridge arms 11 that output the two-phase AC power, the switching module connected to the bridge arm 11 with the short-circuit fault can be controlled to disconnect. In this way, the short-circuit current of that bridge arm 11 will not flow to the windings of drive motor 02, thus protecting drive motor 02.

[0098] This application also provides a powertrain 03, such as Figure 4 As shown, the powertrain 03 includes a motor controller 01 and a drive motor 02 as described in the above embodiment. The motor controller 01 provides three-phase AC power to the drive motor 02 to drive the drive motor 02 to output torque.

[0099] The powertrain 03 includes a resolver sensor and a current sensor. The resolver sensor is used to detect the rotational speed of the drive motor 02, and the current sensor is used to detect the three-phase current value of the drive motor 02. The motor controller 01 is used to receive the rotational speed signal from the resolver sensor and the three-phase current signal from the current sensor. The rotational speed signal is used to indicate the rotational speed of the drive motor 02, and the three-phase current signal is used to indicate the three-phase current value of the drive motor 02.

[0100] This application also includes an electric vehicle, such as... Figure 5 As shown, the electric vehicle includes, Figure 4 The diagram shows the powertrain 03, vehicle controller 05, and power battery 04. The power battery 04 can be used to supply power to the powertrain 03, and the vehicle controller 05 is used to send torque signals to the motor controller 01.

[0101] In this application, the term "at least one" means one or more, and the term "multiple" means two or more.

[0102] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A motor controller (01) having a short-circuit isolation function, characterized by, The motor controller (01) comprises an inverter circuit (1) and a control circuit (2), wherein: The inverter circuit (1) comprises three-phase bridge arms (11), each phase bridge arm (11) comprises an upper bridge arm switch tube (111) and a lower bridge arm switch tube (112), and the bridge arm midpoint (113) of each phase bridge arm (11) is used to connect a phase winding of a driving motor (02) through a switch module (114), and the driving motor (02) is used to drive a vehicle; The control circuit (2) is used to: Control the closing of the switch module (114) corresponding to each phase bridge arm (11), and control the bridge arm midpoint (113) of the three-phase bridge arm (11) to output three-phase current to the three-phase winding of the driving motor (02); During the process that the inverter circuit (1) is used to output the three-phase current, the control circuit (2) is specifically used to: In response to the current through the upper bridge arm switch tube (111) or the lower bridge arm switch tube (112) of at least one phase bridge arm (11) of the three-phase bridge arm (11) being greater than a current threshold value, control the inverter circuit (1) to be in a safety protection state, and the safety protection state comprises an active short circuit ASC state; In response to the control circuit controlling the inverter circuit (1) to be in the safety protection state for a preset time length, control the upper bridge arm switch tube (111) and the lower bridge arm switch tube (112) of the three-phase bridge arm (11) to be turned off; In response to the current through the upper bridge arm switch tube (111) or the lower bridge arm switch tube (112) of the at least one phase bridge arm (11) being greater than zero, control the switch module (114) corresponding to the at least one phase bridge arm (11) to be disconnected, and control the remaining unshort-circuited bridge arms (11) to continue outputting two-phase alternating current to the winding of the driving motor (02).

2. The electric machine controller (01) according to claim 1, characterized in that The motor controller (01) comprises three driving circuits (3), each driving circuit (3) is used to drive the upper bridge arm switch tube (111) and the lower bridge arm switch tube (112) of one phase bridge arm of the three-phase bridge arm, and each driving circuit (3) is used to receive one power supply, and different driving circuits (3) are used to receive different power supplies.

3. The electric machine controller (01) of claim 2, characterized by During the process that the inverter circuit (1) is used to output the three-phase current, the control circuit (2) is used to: In response to the upper bridge arm switch tube (111) or the lower bridge arm switch tube (112) of the at least one phase bridge arm (11) being short-circuited, control the power supply corresponding to the at least one phase bridge arm (11) to stop supplying power.

4. The electric machine controller (01) of claim 1, characterized by During the process that the inverter circuit (1) is used to output the three-phase current, the control circuit (2) is used to: In response to the upper bridge arm switch tube (111) or the lower bridge arm switch tube (112) of the at least one phase bridge arm (11) being short-circuited, output a turn-off signal, and the turn-off signal is used to control the upper bridge arm switch tube (111) and the lower bridge arm switch tube (112) of the at least one phase bridge arm (11) to be turned off.

5. The electric machine controller (01) of claim 1, characterized by During the process that the inverter circuit (1) is used to output the three-phase current, the control circuit (2) is used to: The control circuit (2) is configured to:

6. The electric machine controller (01) of claim 1, characterized by In response to the current through the upper arm switch tube (111) or the lower arm switch tube (112) of at least one phase bridge arm (11) of the three-phase bridge arm (11) being greater than a current threshold, the control circuit (2) is configured to: In response to the current through the upper arm switch tube (111) or the lower arm switch tube (112) of at least one phase bridge arm (11) of the three-phase bridge arm (11) being greater than the current threshold and the rotational speed of the driving motor (02) being greater than a preset rotational speed, the control circuit (2) is configured to control the inverter circuit to be in the safety protection state; 7. The electric machine controller (01) as claimed in claim 1, characterized in that In response to the control circuit controlling the inverter circuit to be in the safety protection state and the rotational speed of the driving motor (02) decreasing to be less than or equal to the preset rotational speed, the control circuit (2) is configured to control the upper arm switch tube (111) and the lower arm switch tube (112) of each phase bridge arm of the three-phase bridge arm (11) to be turned off; In response to the current through the upper arm switch tube (111) or the lower arm switch tube (112) of at least one phase bridge arm (11) being greater than zero, the control circuit (2) is configured to control the switch module (114) corresponding to the at least one phase bridge arm (11) to be turned off. The motor controller (01) is configured to receive a torque signal and control the driving motor (02) to output a torque indicated by the torque signal, and in the process that the inverter circuit (1) is used to output the three-phase current, the control circuit (2) is configured to: In response to the upper arm switch tube (111) or the lower arm switch tube (112) of one phase bridge arm (11) of the three-phase bridge arm (11) being short-circuited, the control circuit (2) is configured to control the switch module (114) corresponding to the at least one phase bridge arm (11) to be turned off; 8. The electric machine controller (01) as claimed in claim 1, characterized in that In response to the switch module (114) corresponding to the one phase bridge arm (11) being turned off, the control circuit (2) is configured to control the bridge arm midpoints (113) of the other two phase bridge arms (11) to output two-phase alternating current, and the two-phase alternating current is used to drive the driving motor (02) to output torque, and the average value of the torque output by the two-phase alternating current driving the driving motor (02) is less than the torque value indicated by the torque signal. In the process that the inverter circuit (1) is used to output the two-phase alternating current, the motor controller (01) is configured to: Control the rotational speed of the driving motor (02) to be less than a preset rotational speed.

9. The electric machine controller (01) of claim 8, characterized by In the process that the inverter circuit (1) is used to output the two-phase alternating current, the control circuit (2) is configured to: In response to the upper arm switch tube (111) or the lower arm switch tube (112) of any one phase bridge arm (11) of the two-phase bridge arm (11) being short-circuited, the control circuit (2) is configured to control the inverter circuit to be in a safety protection state; 10. The electric machine controller (01) of claim 8, characterized by ​ ​ The safety protection state includes an active short-circuit (ASC) state or a shoot-through protection (SPO) state, and the SPO state means that the upper arm switch tube (111) and the lower arm switch tube (112) of each phase bridge arm (11) in the three-phase bridge arm (11) are all turned off.

11. The electric machine controller (01) of claim 8, characterized by In the process that the inverter circuit (1) is used to output the two-phase alternating current, the control circuit is used for: In response to the current through the upper arm switch tube (111) or the lower arm switch tube (112) of one phase bridge arm (11) in the two-phase bridge arm (11) being greater than a current threshold, the control circuit controls the corresponding switch module (114) of the one phase bridge arm (11) in the two-phase bridge arm (11) to be turned off and controls the inverter circuit to be in a safety protection state, The safety protection state includes an active short-circuit (ASC) state or a shoot-through protection (SPO) state, and the SPO state means that the upper arm switch tube (111) and the lower arm switch tube (112) of each phase bridge arm (11) in the three-phase bridge arm (11) are all turned off.

12. A powertrain (03) characterized by, The power assembly (03) includes the motor controller (01) and a drive motor (02), the motor controller (01) is used to receive a torque signal and control the drive motor (02) to output a torque indicated by the torque signal.

13. The powertrain (03) according to claim 12, characterized in that The power assembly (03) includes a resolver sensor and a current sensor, the resolver sensor is used to detect the rotating speed of the drive motor (02), and the current sensor is used to detect the three-phase current value of the drive motor (02), and the motor controller (01) is used to receive a rotating speed signal from the resolver sensor and a three-phase current signal from the current sensor, wherein: The rotating speed signal is used to indicate the rotating speed of the drive motor (02), and the three-phase current signal is used to indicate the three-phase current value of the drive motor (02).

14. An electric vehicle (100), characterized by The electric vehicle (100) includes the power assembly (03), a vehicle controller (05) and a power battery (04), the power battery (04) is used to supply power to the power assembly (03), and the vehicle controller (05) is used to send the torque signal to the motor controller (01).

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