Motor control circuit, method and module, storage medium, controller and vehicle

Abstract

The invention relates to a motor control circuit, method and module, a storage medium, a controller and a vehicle, and the motor control circuit comprises a detection circuit and a protection circuit. The detection circuit is used for detecting a detection parameter generated by the counter electromotive force generated by the motor; and the protection circuit is used for disconnecting the motor and the motor driving circuit when the detection parameter meets a first condition, so as to at least partially solve the problem that the ASC scheme cannot be directly executed, and the bus capacitor and the battery pack are reversely charged by overhigh counter electromotive force through the fly-wheel diode of the switching tube.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and particularly to a motor control circuit, method, module, storage medium, controller and vehicle. Background Art

[0002] For a new energy vehicle powertrain or an industrial inverter that selects a permanent magnet synchronous motor, when the motor runs at high speed, if a serious fault occurs in the motor controller, such as overheating, overcurrent, overvoltage, etc., a shutdown operation will be performed. At this time, the permanent magnet is still rotating at high speed, and a relatively high back electromotive force will be generated in the three-phase windings of the motor.

[0003] In response to this situation, an Active Short Circuit (ASC) scheme is usually adopted, that is, the switch tubes in the upper arm or the lower arm of the inverter in the motor drive circuit are fully turned on to short-circuit the stator windings of the motor. However, the prerequisite for implementing the ASC scheme is that the inverter itself is in a controllable state and the switch tubes can work normally. If there is a fault in the inverter itself, the ASC scheme cannot be directly implemented, resulting in the excessive back electromotive force being back-fed to the bus capacitor and the battery pack through the freewheeling diode of the switch tube. Summary of the Invention

[0004] Embodiments of the present application provide a motor control circuit, method, module, storage medium, controller and vehicle to at least partially solve the problem that when the ASC scheme cannot be directly implemented, the excessive back electromotive force is back-fed to the bus capacitor and the battery pack through the freewheeling diode of the switch tube.

[0005] To achieve the above object, according to the first aspect of the present application, a motor control circuit is provided. The motor control circuit includes: a detection circuit for detecting a detection parameter generated by a back electromotive force generated by a motor; and a protection circuit for disconnecting the connection between the motor and the motor drive circuit when the detection parameter satisfies a first condition.

[0006] In one embodiment, the detection parameter includes at least one of current and temperature.

[0007] In one embodiment, the detection circuit is further configured to: in response to a fault in the inverter in the motor drive circuit and / or a fault in the drive circuit of the inverter, detect the detection parameter generated by the back electromotive force generated by the motor.

[0008] In one embodiment, the detection circuit includes: a current sensor for detecting the phase current of each phase cable between the inverter and the motor.

[0009] In one embodiment, the detection circuit includes: a first temperature sensor for detecting the temperature of each bridge arm in the inverter.

[0010] In one embodiment, the detection circuit includes: a second temperature sensor for detecting the temperature of each phase cable between the inverter and the motor.

[0011] In one embodiment, the detection circuit includes: a third temperature sensor for detecting the temperature of each winding in the motor.

[0012] In one embodiment, the motor control circuit further includes: a controller connected to the detection circuit and the protection circuit, and the controller is configured to control the protection circuit to disconnect according to the detected parameters.

[0013] In one embodiment, the protection circuit includes: a switch for disconnecting the connection between the motor and the motor drive circuit under the control of the controller.

[0014] In one embodiment, one such switch is respectively provided on each phase cable between the inverter in the motor drive circuit and the motor.

[0015] In one embodiment, the protection circuit includes: a fuse for disconnecting the connection between the motor and the motor drive circuit under the control of the controller.

[0016] In one embodiment, the fuse is connected to a first power source; one such fuse is respectively provided on each phase cable between the inverter in the motor drive circuit and the motor; the first power source is configured to provide a fusing current to the fuse under the control of the controller, and the fuse is configured to disconnect the connection between the motor and the motor drive circuit under the action of the fusing current.

[0017] In one embodiment, the controller includes: a detection module for detecting a fault in the inverter in the motor drive circuit and / or the drive circuit of the inverter.

[0018] According to a second aspect of the present application, there is also provided a method for controlling a motor, including: controlling a protection circuit to disconnect the connection between the motor and a motor drive circuit according to a detection parameter generated by a back electromotive force generated by the motor.

[0019] In one embodiment, the method further includes: in response to a fault in the inverter in the motor drive circuit and / or a fault in the drive circuit of the inverter, detecting the detection parameter generated by the back electromotive force generated by the motor.

[0020] In one embodiment, controlling the protection circuit to maintain or disconnect the connection between the motor and the motor drive circuit according to the detection parameter generated from the back electromotive force generated by the motor includes: when the detection parameter satisfies a first condition, the protection circuit disconnects the connection between the motor and the inverter.

[0021] In one embodiment, when the detection parameter satisfies the first condition and the protection circuit disconnects the connection between the motor and the motor drive circuit, it includes: when the absolute value of the integral value of the phase current of any one of the phase cables connected to the inverter is greater than a first threshold, controlling at least two of the multi-phase cables between the inverter and the motor to be disconnected.

[0022] In one embodiment, when the detection parameter satisfies the first condition and the protection circuit disconnects the connection between the motor and the motor drive circuit, it includes: when the temperature difference between two of the multiple bridge arms of the inverter is greater than a first temperature difference threshold, controlling at least two of the multi-phase cables between the inverter and the motor to be disconnected.

[0023] In one embodiment, when the detection parameter satisfies the first condition and the protection circuit disconnects the connection between the motor and the motor drive circuit, it includes: when the temperature of each of the multiple bridge arms of the inverter is greater than a first bridge arm temperature, controlling at least two of the multi-phase cables between the inverter and the motor to be disconnected.

[0024] In one embodiment, when the detection parameter satisfies the first condition and the protection circuit disconnects the connection between the motor and the motor drive circuit, it includes: when the temperature difference between two of the multi-phase cables between the inverter and the motor is greater than a second temperature difference threshold, controlling at least two of the multi-phase cables to be disconnected.

[0025] In one embodiment, when the detection parameter satisfies the first condition and the protection circuit disconnects the connection between the motor and the motor drive circuit, it includes: when the temperature of each of the multi-phase cables between the inverter and the motor is greater than a first cable temperature, controlling at least two of the multi-phase cables to be disconnected.

[0026] In one embodiment, when the detection parameter satisfies the first condition and the protection circuit disconnects the connection between the motor and the motor drive circuit, it includes: when the temperature difference between two of the multiple windings in the motor is greater than a third temperature difference threshold, controlling at least two of the multi-phase cables between the inverter and the motor to be disconnected.

[0027] In one embodiment, when the detection parameter satisfies the first condition, the protection circuit disconnects the connection between the motor and the drive circuit of the motor, including: when the temperature of each of the multiple windings in the motor is greater than the first winding temperature, controlling at least two phases of the multi-phase cable between the inverter and the motor to disconnect.

[0028] According to the third aspect of the present application, there is also provided a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method described in any of the above embodiments are implemented.

[0029] According to the fourth aspect of the present application, there is also provided a controller, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method described in any of the above embodiments are implemented.

[0030] According to the fifth aspect of the present application, there is also provided a motor control module, including the motor control circuit described in any of the above embodiments.

[0031] According to the sixth aspect of the present application, there is also provided a vehicle, including the motor control module described in any of the above embodiments, or including the motor control circuit described in any of the above embodiments.

[0032] In summary, the embodiments of the present application provide a motor control circuit, method, module, storage medium, controller, and vehicle. Among them, the motor control circuit includes a detection circuit and a protection circuit. The detection circuit is used to detect the detection parameter generated by the back electromotive force generated by the motor; the protection circuit is used to maintain or disconnect the connection between the motor and the motor drive circuit. By disconnecting the connection between the motor and the motor drive circuit when the detection parameter satisfies the first condition, at least partially solve the problem that the ASC scheme cannot be directly executed, resulting in excessive back electromotive force being reverse-fed to the bus capacitor and the battery pack through the freewheeling diode of the switching tube, and effectively avoid current reverse-feeding when there is a fault in the inverter itself.

[0033] Other features and advantages of the present application will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative efforts.

[0035] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, where the same reference numerals represent the same parts in the following description.

[0036] Figure 1 It is a schematic structural diagram of a motor control circuit provided in an alternative embodiment of the present application;

[0037] Figure 2 It is a schematic structural diagram of another motor control circuit provided in an alternative embodiment of the present application;

[0038] Figure 3 It is a schematic structural diagram of another motor control circuit provided in an alternative embodiment of the present application;

[0039] Figure 4 It is a schematic structural diagram of another motor control circuit provided in an alternative embodiment of the present application;

[0040] Figure 5 It is a flowchart of a motor control method provided in an alternative embodiment of the present application;

[0041] Figure 6 It is a flowchart of a motor control method provided in an alternative embodiment of the present application;

[0042] Figure 7 It is a flowchart of another motor control method provided in an alternative embodiment of the present application;

[0043] Figure 8 It is a flowchart of another motor control method provided in an alternative embodiment of the present application;

[0044] Figure 9 It is a flowchart of another motor control method provided in an alternative embodiment of the present application;

[0045] Figure 10 It is a schematic structural diagram of a motor protection module provided in an alternative embodiment of the present application;

[0046] Figure 11 It is a schematic structural diagram of a vehicle provided in an alternative embodiment of the present application. Detailed implementation manners

[0047] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0048] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0049] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection, an electrical connection or a connection capable of mutual communication; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0050] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0051] The various embodiments provided in the present application are similar, and the features in different embodiments can be combined and replaced with each other without conflict.

[0052] The use of "configured to" and "for" in the embodiments of the present application means open and inclusive language, which does not exclude devices suitable for or configured to perform additional tasks or steps.

[0053] The description order of the following embodiments does not serve as a limitation on the preferred order of the embodiments.

[0054] The motor controller is a core component of new energy vehicles. For new energy vehicle powertrains or industrial inverters using permanent magnet synchronous motors, if a serious motor controller fault occurs during high-speed operation, such as overtemperature, overcurrent, or overvoltage, the motor will shut down. During this time, the high-speed rotation of the permanent magnets generates a high back-EMF in the three-phase windings of the motor. If all the switches in a three-phase bridge inverter are turned off, the excessive back-EMF will flow back through the freewheeling diodes of the power switches into the bus capacitors and battery pack, causing uncontrolled rectification. This can lead to DC bus overvoltage and significant generator braking torque, which can overcharge and damage the battery or increase the risk of rollover.

[0055] To address the above situation, an active short circuit (ASC) solution is usually adopted, which is to short-circuit the motor stator winding by fully turning on the three switching tubes in the upper or lower arm of the inverter, so that the vehicle can enter a relatively safe state in the event of a collision or other fault.

[0056] The above-mentioned ASC solution is based on the premise that the three-phase inverter is controllable. When the motor controller loses control of the three-phase inverter during operation (that is, the three-phase inverter power tube fails or the power tube drive circuit fails), the power tube driver chip will report the intelligent power module (Intelligent Power Module, referred to as IPM) failure to the motor controller and shut down the drive output. The motor controller cannot control the inverter action, and active short circuit cannot intervene at this time. In the whole vehicle, IPM refers to the integration of power module and driver circuit board. Among them, intelligence refers to the drive part, which is used to control the opening and closing of the power module switch tube (such as IGBT, SiC MOSFET); the function of the power module is to convert the DC output of the battery pack into three-phase AC to drive the permanent magnet synchronous motor to operate.

[0057] If a three-phase inverter power transistor fails, it's unclear which module phase is short-circuited or open. If three-phase short-circuit protection is rashly activated when one phase of the inverter is short-circuited, the inverter's upper and lower bridge arms will be directly connected, short-circuiting the battery pack and creating a risk of rapid energy accumulation in the inverter, leading to a fire. Even if the short-circuited power transistor in the arm can be detected, if the upper and lower bridge power devices of two phases of the inverter are short-circuited, the three-phase short-circuit protection will not be able to activate by opening the upper or lower bridge. This will inevitably cause the upper and lower bridge arms of the inverter to be directly connected, short-circuiting the battery pack and creating a risk of rapid energy accumulation in the inverter, leading to a fire.

[0058] In order to solve the above problems, an embodiment of the present application provides a motor control circuit. Figure 1The following is a schematic structural diagram of a motor control circuit provided in an alternative embodiment of the present application. Refer to Figure 1 As shown, the motor control circuit 100 provided in the embodiment of the present application includes a detection circuit 110 and a protection circuit 120. The detection circuit 110 is used to detect a detection parameter generated by the back electromotive force generated by the motor 200; the protection circuit 120 is used to disconnect the connection between the motor 200 and the motor drive circuit 300.

[0059] When the detection parameter satisfies the first condition, the protection circuit 120 disconnects the connection between the motor 200 and the motor drive circuit 300.

[0060] When the detection parameter does not satisfy the first condition, the protection circuit 120 remains unchanged, which can be understood as maintaining the connection between the motor 200 and the motor drive circuit 300, or keeping the motor 200 and the motor drive circuit 300 conducting.

[0061] By disconnecting the connection between the motor and the motor drive circuit when the detection parameter satisfies the first condition through the protection circuit, it is possible to at least partially solve the problem that the ASC scheme cannot be directly executed, resulting in excessive back electromotive force being back-fed to the bus capacitor and the battery pack through the freewheeling diode of the switching tube, effectively avoiding current back-feeding when there is a fault in the inverter itself.

[0062] Figure 2 The following is a schematic structural diagram of another motor control circuit provided in an alternative embodiment of the present application. Refer to Figure 2 As shown, the motor drive circuit 300 may include an inverter 310, a bus capacitor C1, a battery pack 320, and a cable 330 for connecting the inverter 310 and the motor 200.

[0063] The inverter 310 may be a single-phase inverter or a multi-phase inverter. In the embodiment of the present application, a three-phase inverter is taken as an example for illustrative purposes. Correspondingly, the motor 200 in the embodiment of the present application may be a three-phase winding motor. The inverter 310 and the motor 200 may be connected by a three-phase cable, and the three-phase cable corresponds to the U, V, and W phases of the motor 200 respectively. The inverter 310 may include six bridge arms in total for the U, V, and W phases (corresponding to three upper half-bridge arms and three lower half-bridge arms). Each phase includes an upper bridge and a lower bridge, and the bridge arms are realized through switching tubes (Q1 to Q6).

[0064] By controlling the conduction or disconnection of the six switching tubes in the inverter 310, it is possible to charge the bus capacitor C1 from the battery pack 320, and then charge the motor 200 forward, and to charge the battery pack 320 from the motor 200 in reverse. The above charging process can be realized by conventional techniques in the art, and will not be specifically described in the embodiment of the present application.

[0065] In some embodiments, the detection parameter may include at least one of current and temperature. For example, it may be the phase current of each phase cable connected to the inverter 310, that is, the current flowing through each phase cable between the inverter 310 and the motor 200. It may be the temperature of each switching device in the inverter 310, the temperature of each phase cable between the inverter 310 and the motor 200, or the temperature of each phase winding in the motor 200.

[0066] Referring to Figure 3 As shown, in some embodiments, the motor control circuit 100 further includes: a controller 130, connected to the detection circuit 110 and the protection circuit 120. The controller 130 is configured to control the protection circuit 120 to disconnect according to the detection parameter, and may also control the protection circuit 120 to conduct or remain in its original state. The detection circuit 110 sends the collected detection parameter to the controller 130. After processing the detection parameter, the controller 130 determines whether it is necessary to disconnect the protection circuit 120. If it is necessary to disconnect, a corresponding disconnection control instruction is sent to the protection circuit 120; if it is not necessary to disconnect, a corresponding conduction control instruction may be sent to the protection circuit 120, or no instruction may be sent, so that the protection circuit 120 remains in its original state.

[0067] The controller 130 may be integrated in the micro - controller unit (MCU) of the original motor drive circuit, or may exist independently of the motor drive circuit in the motor control circuit. The embodiments of the present application do not limit this.

[0068] In some embodiments, the protection circuit 120 includes at least one switch, and a switch is respectively arranged on each phase cable between the inverter 310 and the motor 200. Specifically, the protection circuit 120 may include at least one fuse, and a fuse is respectively arranged on each phase cable between the inverter 310 and the motor 200. The fuse is connected to a first power source. When receiving an instruction sent by the controller 130, the first power source sends a fusing current, generally a current greater than or equal to 2A, to the fuse. After receiving the fusing current, the fuse melts the corresponding cable through self - heating, thereby disconnecting the connection between the motor 200 and the inverter 310. The cable in the embodiments of the present application may be implemented by conductive materials such as copper bars and aluminum alloys, and the first power source may be any in - vehicle power source.

[0069] In some embodiments, the controller 130 may include a detection module 1301 for detecting whether there is a fault in the inverter and / or the drive circuit of the inverter. The detection module 1301 can be understood as an IPM fault detection module, which is used to report an IPM fault when a switching tube of the inverter fails and / or the drive circuit of the inverter fails. The detection module 1301 can be integrated inside the controller 130 or can be provided on the drive circuit board of the IPM. According to the foregoing, IPM refers to the integration of a power module and a drive circuit board. The drive circuit board is provided with a drive chip of the inverter, and the detection function can be integrated in the drive chip to detect IPM faults and then report them to the controller.

[0070] In some embodiments, the detection circuit 110 is further configured to: in response to a fault in the inverter and / or the drive circuit of the inverter (i.e., IPM fault) in the motor drive circuit, detect a detection parameter generated by the back electromotive force generated by the motor. To avoid false alarms of IPM faults, the detection circuit 110 further detects the detection parameter generated by the back electromotive force generated by the motor, which is equivalent to a secondary guarantee. When the detection parameter meets the first condition, the controller 130 controls the protection circuit 120 to disconnect the cable 340, that is, to disconnect the connection between the motor 200 and the motor drive circuit 300.

[0071] In some embodiments, the detection circuit 110 may include a current sensor for detecting the phase current of each phase cable 340 in the multi-phase cable connected to the inverter 310. The current sensor in the embodiment of the present application can be implemented by a Hall sensor or other sensors that can detect current. When a switching tube of the inverter 310 fails or the drive circuit of the switching tube fails, the controller 130 will report an IPM fault. At this time, the detection circuit 110 detects the phase current of each phase cable 340. When the absolute value of the integral value of the phase current of a certain phase of the inverter detected at this time is greater than the first threshold, it can be determined that there is a short circuit between the inverter, the three-phase line (equivalent to the cable), or the permanent magnet synchronous motor winding, and the current will suddenly surge, resulting in overheating and damage of the inverter 310, and there is a risk of rapid energy accumulation leading to fire.

[0072] Among them, the value of the phase current integral value is affected by two factors of the whole vehicle. One is affected by the voltage of the battery pack, and the other is affected by the internal resistance of the half-bridge short circuit of the power module. These two variables are related to the specific vehicle model. For a 300V battery pack and an internal resistance of 0.1Ω, the corresponding strategy is: when IPM fault & motor speed (≤6000r / min) & the phase current of one phase > 10A, trigger open circuit protection; when IPM fault & motor speed (>6000r / min) & the integral value of the three-phase current > 45, trigger open circuit protection. Open circuit protection requires disconnecting at least two of the three-phase cables.

[0073] In some embodiments, the detection circuit 110 may further include a first temperature sensor for detecting the temperature of each arm of the inverter 310. When the vehicle is running at high speed, if an IPM fault occurs, the motor controller will forcibly turn off the six drive signals for driving the inverter 310. When a short circuit occurs in one arm of a phase, the first temperature sensor can detect that the temperature of this arm of the phase is greater than that of the other two phases, and the temperatures of the two non-shorted phases are approximately equal. If it is found that the temperature difference between a certain phase and the other two phases is greater than the first temperature difference threshold, it can be considered that a short circuit fault has occurred in the phase with the excessive temperature. It should be understood that one arm of a phase includes the upper and lower arms connected to the same phase cable. For example, when the difference between the temperatures T1 of the two arms connected to the U-phase cable and the temperatures T2 of the two arms connected to the V-phase cable is greater than the first temperature difference threshold and T1 > T2, it can be determined that at least one arm connected to the U-phase cable has a fault; when the difference between the temperatures T1 of the two arms connected to the U-phase cable and the temperatures T3 of the two arms connected to the W-phase cable is greater than the first temperature difference threshold and T1 > T3, it can be determined that at least one arm connected to the U-phase cable has a fault. When the difference between the temperatures T1 of the two arms connected to the U-phase cable and the temperatures T2 of the two arms connected to the V-phase cable is greater than the first temperature difference threshold and T1 > T2, and at the same time the difference between the temperatures T3 of the two arms connected to the W-phase cable and the temperatures T1 of the two arms connected to the U-phase cable is greater than the first temperature difference threshold and T3 > T1, it can be determined that at least one arm connected to the W-phase cable and at least one arm connected to the U-phase cable have both failed.

[0074] When it is found that the temperatures of two of the three arms in the upper bridge are much greater than that of the other arm, it can be determined that a short circuit fault has occurred in the two arms with high temperatures; or when the temperatures of two of the three arms in the lower bridge are much greater than that of the other arm, it can be determined that a short circuit fault has occurred in these two arms with high temperatures. When it is found that the temperatures of the three arms in the upper bridge are all much greater than the temperature of the first arm, it can be determined that all three arms have a short circuit fault; when it is found that the temperatures of the three arms in the lower bridge are all much greater than the temperature of the first arm, it can be determined that all three arms have a short circuit fault. Therefore, it is possible to determine whether to disconnect the protection circuit 120 by judging whether the IPM fault and the temperature difference between the three-phase inverter arms are greater than the set first temperature difference threshold, or whether the temperatures of individual arms are all greater than the set first arm temperature.

[0075] In some embodiments, the detection circuit 110 may further include a second temperature sensor for detecting the temperature of each phase cable 330 between the inverter 310 and the motor 200. When the vehicle is running at high speed, if an IPM fault occurs, the motor controller will forcibly turn off the six drive signals of the drive inverter 310. If it is found that the temperature difference between one phase cable and the other two phase cables is greater than the second temperature difference threshold, it can be considered that a short - circuit fault has occurred in the phase with excessive temperature. When it is found that the temperatures of two phase cables are much higher than that of the other one - phase cable, and the temperature difference between the cables is greater than the second temperature difference threshold or other set thresholds, it can be determined that a short - circuit fault has occurred in two phases. When it is found that the temperatures of the three phase cables are all much higher than the temperature of the first cable or other set temperatures, it can be determined as a three - phase short - circuit fault. Whether it is a single - phase short - circuit, two - phase short - circuit or three - phase short - circuit, at least two phase cables need to be disconnected through the protection circuit 120.

[0076] Referring to Figure 4 As shown, in some embodiments, the detection circuit may further include a third temperature sensor 1101 for detecting the temperature of each winding in the motor 200. When the vehicle is running at high speed, if an IPM fault occurs, the motor controller will forcibly turn off the six drive signals of the drive inverter. If it is found that the temperature difference between a certain phase winding of the motor 200 and the other two phase windings is greater than the third temperature difference threshold, it can be considered that a short - circuit fault has occurred in the phase winding with excessive temperature. When it is found that the temperatures of two phase windings are much higher than that of the other one - phase winding, and the temperature difference between the windings is greater than the third temperature difference threshold or other set thresholds, it can be determined that a short - circuit fault has occurred in two phases. When it is found that the temperatures of the three phase windings are all much higher than the temperature of the first winding or other set temperatures, it can be determined as a three - phase short - circuit fault. Whether it is a single - phase short - circuit, two - phase short - circuit or three - phase short - circuit, at least two phase cables need to be disconnected through the protection circuit 120.

[0077] In some embodiments, the motor 200 may be implemented by a permanent - magnet synchronous motor. The rotor of the permanent - magnet synchronous motor is a permanent magnet, and the winding coils are on the stator. When the motor rotor rotates, the magnetic field generated by the rotor permanent magnet will rotate and be cut by the stator coils, generating a back electromotive force in the coils.

[0078] It should be noted that the relationship between the back electromotive force and the electrical angular velocity of the permanent - magnet synchronous motor is shown in the following formula 1. The higher the speed of the permanent - magnet synchronous motor, the greater its back electromotive force.

[0079] Formula 1: E = √3ω e φ f .

[0080] Where, E represents the back electromotive force of the permanent - magnet synchronous motor, ω e represents the electrical angular velocity of the permanent - magnet synchronous motor, and φ f represents the back - electromotive - force constant of the motor rotor.

[0081] According to another embodiment of the present application, a motor control method is also provided, which is applied to the motor control circuit described in any of the above embodiments. The functions that can be achieved by the above motor control circuit can all be achieved by this method, and the content that has been described will not be repeated here. Figure 5 This is a flow chart of a motor control method provided in an optional embodiment of the present application, with reference to Figure 5 As shown, the motor control method includes:

[0082] Step S501 : Controlling the protection circuit to disconnect the motor from the motor drive circuit according to a detection parameter generated by the back electromotive force generated by the motor.

[0083] By disconnecting the motor from the motor drive circuit when the detection parameter meets the first condition; and maintaining the connection between the motor and the motor drive circuit when the detection parameter does not meet the first condition, the problem of being unable to directly execute the ASC solution, resulting in excessive back electromotive force back-feeding the bus capacitor and the battery pack through the freewheeling diode of the switching tube, can be at least partially solved, effectively avoiding current back-feeding caused by a fault in the inverter itself.

[0084] In some embodiments, the method further includes: in response to a failure of an inverter in the motor drive circuit and / or a failure of a drive circuit of the inverter, detecting the detection parameter generated by the back electromotive force generated by the motor.

[0085] In some embodiments, the detected parameter includes at least one of current and temperature. For example, the detected parameter may be the phase current of each phase cable between the inverter 310 and the motor 200, the temperature of each bridge arm (i.e., a switch) in the inverter 310, the temperature of each phase cable between the inverter 310 and the motor 200, or the temperature of each phase winding in the motor 200.

[0086] In some embodiments, the above step S501 can be implemented by the following steps: when the detection parameter meets the first condition, the protection circuit disconnects the motor from the driving circuit of the motor.

[0087] In some embodiments, reference Figure 6 As shown, step S501 can be implemented by the following steps: when the absolute value of the phase current integral value of any phase cable connected to the inverter is greater than a first threshold, disconnecting at least two phases of the multi-phase cable between the inverter and the motor. Specifically, a permanent magnet synchronous motor and a three-phase inverter are used as an example for the following exemplary description.

[0088] S1, when the permanent magnet synchronous motor controller and the three-phase inverter are powered on, the permanent magnet synchronous motor controller will control the switch tubes of the three-phase inverter to switch on and off in an orderly manner to drive the permanent magnet synchronous motor to operate.

[0089] At S2, the permanent magnet synchronous motor controller detects the status of the three-phase inverter in real time through the three-phase inverter fault detection device and the three-phase current detection device.

[0090] At S3, when the permanent magnet synchronous motor controller detects that there is no IPM fault in the three-phase inverter or the integrated values of the phase currents are all near 0, the permanent magnet synchronous motor controller normally controls the power switch tubes of the three-phase inverter to drive the permanent magnet synchronous motor to operate, and the motor controller continues to detect the status information. When there is a fault in the switch tube of the three-phase inverter or a fault in the drive circuit of the switch tube, the permanent magnet synchronous motor controller will report an IPM fault and forcibly turn off the six drive signals for driving the three-phase inverter, causing the six bridge arms of the three-phase inverter to remain open. At this time, the high-speed rotating permanent magnet synchronous motor will generate a large back electromotive force. When the back electromotive force is greater than the voltage of the battery pack, a phase current will be generated, and the bus capacitor and the battery pack will be back-fed through the freewheeling diode of the power switch tube for uncontrolled rectification.

[0091] If condition 2 is not satisfied at this time, it proves that the three-phase inverter is not damaged at this time, and the existing three-phase active short-circuit protection strategy (for example, the ASC scheme) can be used to ensure driving safety.

[0092] When it is also detected at this time that the absolute value of the integrated value of the phase current of a certain phase cable connected to the inverter is greater than the first threshold, it can be determined that there is a short circuit between the inverter, the three-phase line or the winding of the permanent magnet synchronous motor at this time, and the current will suddenly surge, resulting in overheating damage of the three-phase inverter and the risk of rapid energy accumulation leading to fire.

[0093] At S4, judge the fault situation to determine whether condition 1 (there is an IPM fault) and condition 2 (the absolute value of the integrated value of the phase current is too large) are both satisfied.

[0094] At S5, once both the IPM fault and the excessive integrated value of the phase current occur, immediately disconnect the protection circuit.

[0095] By using the motor three-phase disconnection device (equivalent to the aforementioned protection circuit) to timely disconnect two or three phases of the three-phase lines of the permanent magnet synchronous motor, the connection between the permanent magnet synchronous motor and the three-phase inverter can be cut off. The three-phase lines of the permanent magnet synchronous motor cannot form a current-carrying loop, no current is generated, and the three-phase inverter and the battery pack will not be damaged.

[0096] For the detection method of the three-phase current, in addition to using Hall sensors for detection, corresponding current detection chips can also be used, or current sensors can be integrated in the switch tubes of the inverter, etc. As long as it is a method of controlling the three-phase disconnection device by judging the integrated value of the three-phase current, it is within the protection scope of this application.

[0097] Refer to Figure 7As shown, in some embodiments, the above step S501 can also be implemented through the following steps: when the temperature difference between two of the multiple bridge arms of the inverter is greater than the first temperature difference threshold, control at least two of the multiple-phase cables between the inverter and the motor to be disconnected. Specifically, taking a permanent magnet synchronous motor and a three-phase inverter as an example, the following exemplary description is given.

[0098] S1. After the permanent magnet synchronous motor controller and the three-phase inverter are powered on, the permanent magnet synchronous motor controller will control the switching tubes of the three-phase inverter to switch orderly to drive the permanent magnet synchronous motor to operate.

[0099] S2. At this time, the permanent magnet synchronous motor controller detects the state of the three-phase inverter in real time through the three-phase inverter fault detection device and the three-phase current detection device.

[0100] S3. When the vehicle is running at high speed, if an IPM fault occurs, the motor controller will forcibly turn off the six drive signals of the drive inverter 310. When a phase bridge arm is short-circuited, the first temperature sensor can detect that the temperature of this phase bridge arm is higher than the other two phases, and the temperatures of the two non-shorted phases are nearly equal. If it is found that the temperature difference between a certain phase and the other two phases is greater than the first temperature difference threshold, it can be considered that the phase with too high temperature has a short-circuit fault. When it is found that the temperatures of two bridge arms are much higher than the other bridge arm, and the bridge arm temperature difference is greater than the first temperature difference threshold or other set thresholds, it can be determined that there is a short-circuit fault in these two bridge arms of the three-phase inverter. When it is found that the temperatures of the three bridge arms are much higher than the temperature of the first bridge arm or other set temperatures at this time, it can be determined that all three bridge arms of the three-phase inverter have a short-circuit fault.

[0101] S4. Judge the fault situation to see if conditions 1 (there is an IPM fault) and 2 (the temperature difference between the bridge arms of the inverter is too large) are both satisfied at the same time.

[0102] S5. Once both the IPM fault and the over-large phase current integral value occur, immediately disconnect the protection circuit.

[0103] Refer to Figure 8 As shown, in some embodiments, the above step S501 can also be implemented through the following steps: when the temperature difference between two of the multiple-phase cables between the inverter and the motor is greater than the second temperature difference threshold, control at least two of the multiple-phase cables to be disconnected. Specifically, taking a permanent magnet synchronous motor and a three-phase inverter as an example, the following exemplary description is given.

[0104] S1. After the permanent magnet synchronous motor controller and the three-phase inverter are powered on, the permanent magnet synchronous motor controller will control the switching tubes of the three-phase inverter to switch orderly to drive the permanent magnet synchronous motor to operate.

[0105] S2. At this time, the permanent magnet synchronous motor controller detects the status of the three-phase inverter in real time through the three-phase inverter fault detection device and the three-phase current detection device.

[0106] S3. When the vehicle is running at high speed, if an IPM fault occurs, the motor controller will forcibly turn off the six drive signals of the drive inverter 310. If it is found that the temperature difference between one phase cable and the other two phase cables is greater than the second temperature difference threshold, it can be considered that a short circuit fault has occurred in the phase with excessive temperature. When it is found that the temperatures of two phase cables are much higher than that of the other one phase cable, and the cable temperature difference is greater than the second temperature difference threshold or other set thresholds, it can be determined that a short circuit fault has occurred in two phases. When it is found that the temperatures of the three phase cables are all much higher than the set first cable temperature, it can be determined as a three-phase short circuit fault.

[0107] S4. Judge the fault situation to see if both condition 1 (there is an IPM fault) and condition 2 (the cable temperature rise is excessive) are satisfied at the same time.

[0108] S5. Once both the IPM fault and the excessive phase current integral value occur, immediately disconnect the protection circuit.

[0109] Refer to Figure 9 As shown, in some embodiments, the above step S501 can also be implemented through the following steps: When the temperature difference between two of the multi-phase windings in the motor is greater than the third temperature difference threshold, control at least two of the multi-phase cables to disconnect. Specifically, taking the permanent magnet synchronous motor and the three-phase inverter as an example, the following exemplary description is given.

[0110] S1. After the permanent magnet synchronous motor controller and the three-phase inverter are powered on, the permanent magnet synchronous motor controller will control the switching tubes of the three-phase inverter to switch orderly to drive the permanent magnet synchronous motor to operate.

[0111] S2. At this time, the permanent magnet synchronous motor controller detects the status of the three-phase inverter in real time through the three-phase inverter fault detection device and the three-phase current detection device.

[0112] S3. When the vehicle is running at high speed, if an IPM fault occurs, the motor controller will forcibly turn off the six drive signals of the drive inverter. If it is found that the temperature difference between one phase winding of the motor 200 and the other two phase windings is greater than the fourth threshold (preset temperature difference threshold), it can be considered that a short circuit fault has occurred in the phase with excessive temperature. When it is found that the temperatures of two phase windings are much higher than that of the other one phase winding, and the winding temperature difference is greater than the third temperature difference threshold or other set thresholds, it can be determined that a short circuit fault has occurred in two phases. When it is found that the temperatures of the three phase windings are all much higher than the first winding temperature or other set temperatures, it can be determined as a three-phase short circuit fault.

[0113] S4. Judge the fault situation to see if both condition 1 (there is an IPM fault) and condition 2 (the motor winding temperature difference is excessive) are satisfied at the same time.

[0114] S5. Once both the IPM fault and the excessive integral value of the phase current occur, the protection circuit is immediately disconnected.

[0115] The motor control circuit and the motor control method provided by the embodiments of the present application can, while detecting the IPM fault signal, comprehensively determine when to disconnect the protection circuit by judging the absolute value of the integral value of the phase current over a period of time (one cycle or multiple cycles). When a fault occurs in the inverter (whether it is a short circuit or an open circuit), or a fault occurs in the drive circuit, or a short circuit occurs in the internal windings of the motor and the external three-phase cables of the motor, the connection between the motor and the inverter can be disconnected in a timely manner to avoid the harm caused by the excessive back electromotive force of the motor.

[0116] The embodiments of the present application also provide a computer-readable storage medium. Instructions are stored on the machine-readable storage medium, and when the instructions are executed by a processor, the processor is configured to execute the above-mentioned motor control method. For example, the following steps can be executed:

[0117] S1. According to the detection parameter generated by the back electromotive force generated by the motor, control the protection circuit to maintain or disconnect the connection between the motor and the motor drive circuit.

[0118] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0119] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0120] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction device that implements the functions specified in one or more of the processes and / or boxes Figure 1 in one or more of the processes and / or boxes Figure 1 specified in the box or boxes.

[0121] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are performed on the computer or other programmable device to produce a computer-implemented process, thereby providing steps for implementing the functions specified in one or more of the processes and / or boxes Figure 1 in one or more of the processes and / or boxes Figure 1 specified in the box or boxes.

[0122] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0123] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.

[0124] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology for information storage. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media such as modulated communication signals and carrier waves.

[0125] Referring Figure 10 as shown, another embodiment of the present application further provides a motor protection module 10, including the motor control circuit 100 described in any of the above embodiments.

[0126] Reference Figure 11 As shown, another embodiment of the present application further provides a vehicle 1000, including the above-mentioned motor protection module 10, or the motor control circuit 100 described in any of the above embodiments. In this embodiment, the vehicle can be a fuel vehicle, a plug-in hybrid vehicle, a new energy vehicle, etc., and the present disclosure does not make specific limitations thereto.

[0127] The above are only the preferred embodiments of the present application, and do not impose any form of limitation on the present application. However, any simple modifications, equivalent changes, and decorations made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of the technical solution of the present application.

Claims

1. A motor control circuit, characterized in that, The motor control circuit includes: a detection circuit for detecting a detection parameter generated by a back electromotive force generated by the motor; and a protection circuit for disconnecting the connection between the motor and the motor drive circuit when the detection parameter satisfies a first condition.

2. The motor control circuit according to claim 1, wherein, The detection parameter includes: at least one of current and temperature.

3. The motor control circuit according to claim 2, characterized in that The detection circuit is further configured to: in response to a fault of an inverter in the motor drive circuit and / or a fault of a drive circuit of the inverter, detect the detection parameter generated by the back electromotive force generated by the motor.

4. The motor control circuit according to claim 3, wherein The detection circuit includes: a current sensor for detecting a phase current of each phase cable between the inverter and the motor.

5. The motor control circuit according to claim 3, characterized in that, The detection circuit includes: a first temperature sensor for detecting the temperature of each arm in the inverter.

6. The motor control circuit according to claim 3, characterized in that, The detection circuit includes: a second temperature sensor for detecting the temperature of each phase cable between the inverter and the motor.

7. The motor control circuit according to claim 3, wherein, The detection circuit includes: a third temperature sensor for detecting the temperature of each winding in the motor.

8. The motor control circuit according to claim 1, wherein The motor control circuit further includes: a controller connected to the detection circuit and the protection circuit, the controller being configured to control the protection circuit to disconnect according to the detection parameter.

9. The motor control circuit according to claim 8, wherein The protection circuit includes: a switch for disconnecting the connection between the motor and the motor drive circuit under the control of the controller.

10. The motor control circuit according to claim 9, characterized in that, One such switch is respectively provided on each phase cable between the inverter in the motor drive circuit and the motor.

11. The motor control circuit according to claim 8, characterized in that, The protection circuit includes: a fuse for disconnecting the connection between the motor and the motor drive circuit under the control of the controller.

12. The motor control circuit according to claim 11, characterized in that, The fuse is connected to a first power supply; one such fuse is respectively provided on each phase cable between the inverter in the motor drive circuit and the motor; the first power supply is configured to provide a fusing current to the fuse under the control of the controller, and the fuse is configured to disconnect the connection between the motor and the motor drive circuit under the action of the fusing current.

13. The motor control circuit according to claim 8, wherein, The controller includes: a detection module for detecting a fault of an inverter in the motor drive circuit and / or a fault of a drive circuit of the inverter.

14. A motor control method, characterized in that, including: controlling the protection circuit to disconnect the connection between the motor and the motor drive circuit according to a detection parameter generated by a back electromotive force generated by the motor.

15. The motor control method according to claim 14, wherein The method further includes: in response to a fault of an inverter in the motor drive circuit and / or a fault of a drive circuit of the inverter, detecting the detection parameter generated by the back electromotive force generated by the motor.

16. The motor control method according to claim 15, characterized in that, The controlling the protection circuit to maintain or disconnect the connection between the motor and the motor drive circuit according to a detection parameter generated by a back electromotive force generated by the motor includes: when the detection parameter satisfies a first condition, the protection circuit disconnects the connection between the motor and the inverter.

17. The motor control method according to claim 16, wherein The when the detection parameter satisfies a first condition, the protection circuit disconnects the connection between the motor and the motor drive circuit includes: when the absolute value of the integral value of the phase current of any phase cable connected to the inverter is greater than a first threshold, controlling at least two of the multi-phase cables between the inverter and the motor to disconnect.

18. The motor control method according to claim 16, characterized in that, When the detection parameter satisfies the first condition, the protection circuit disconnects the connection between the motor and the driving circuit of the motor, including: When the temperature difference between two of the multiple bridge arms of the inverter is greater than the first temperature difference threshold, control at least two of the multiple-phase cables between the inverter and the motor to disconnect.

19. The motor control method according to claim 16, characterized in that, When the detection parameter satisfies the first condition, the protection circuit disconnects the connection between the motor and the driving circuit of the motor, including: When the temperature of each of the multiple bridge arms of the inverter is greater than the first bridge arm temperature, control at least two of the multiple-phase cables between the inverter and the motor to disconnect.

20. The motor control method according to claim 16, wherein When the detection parameter satisfies the first condition, the protection circuit disconnects the connection between the motor and the driving circuit of the motor, including: When the temperature difference between two of the multiple-phase cables between the inverter and the motor is greater than the second temperature difference threshold, control at least two of the multiple-phase cables to disconnect.

21. The motor control method according to claim 16, characterized in that, When the detection parameter satisfies the first condition, the protection circuit disconnects the connection between the motor and the driving circuit of the motor, including: When the temperature of each of the multiple-phase cables between the inverter and the motor is greater than the first cable temperature, control at least two of the multiple-phase cables to disconnect.

22. The motor control method according to claim 16, wherein When the detection parameter satisfies the first condition, the protection circuit disconnects the connection between the motor and the driving circuit of the motor, including: When the temperature difference between two of the multiple windings in the motor is greater than the third temperature difference threshold, control at least two of the multiple-phase cables between the inverter and the motor to disconnect.

23. The motor control method according to claim 16, characterized in that, When the detection parameter satisfies the first condition, the protection circuit disconnects the connection between the motor and the driving circuit of the motor, including: When the temperature of each of the multiple windings in the motor is greater than the first winding temperature, control at least two of the multiple-phase cables between the inverter and the motor to disconnect.

24. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 14 to 23.

25. A controller, on which a computer program is stored, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 14 to 23.

26. A motor control module, characterized in that, Including the motor control circuit according to any one of claims 1 to 13.

27. A vehicle, characterized in that, Including the motor control module according to claim 26, or including the motor control circuit according to any one of claims 1 to 13.

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