Safety state control method, device, equipment and medium for motor controller

Abstract

The present application provides a method, apparatus, device, and medium for controlling the safety state of a motor controller. The method includes: obtaining the current voltage and current speed of the motor; determining a target switching point representing the safety state of the motor controller based on the current voltage and a preset output torque curve; determining a first switching speed corresponding to the target switching point based on the preset output torque curve; comparing the current speed with the first switching speed; and adjusting the current safety state of the motor controller to a target safety state based on the first comparison result. The target safety state includes an open-circuit protection safety state and an active protection safety state. By determining the target switching point of the safety state in real time through the current voltage and output torque curve, the target switching point is different under different voltages. Combined with the current speed, the target safety state of the motor controller is controlled, which can ensure zero torque or safe braking torque while avoiding damage to components, thereby improving the safety and controllability of the vehicle.

Description

Technical Field

[0001] The present invention relates to the field of motor control technology, and in particular to a safety state control method, device, equipment and medium for a motor controller. Background Art

[0002] In electric vehicles, the motor controller can control the starting, forward and backward speed, climbing strength and other driving states of the electric vehicle according to the gear, throttle, brake and other instructions. When a vehicle fault occurs and affects driving safety, it is necessary to formulate a reasonable control strategy to put the vehicle into a safe state to ensure the safety of the vehicle and the people on board. There are two safe states of the motor controller: active short circuit (ASC) and open circuit protection (FW). Among them, active short circuit (ASC) has the following characteristics: (1) significant braking torque is generated in the low-speed zone; (2) the continuous current generated by the back electromotive force will cause the motor to overheat; (3) the risk of rotor magnet demagnetization caused by motor overheating; (4) the inverter overheating caused by motor overheating leads to inverter damage. Open circuit protection (FW) has the following characteristics: (1) phase current flows through the freewheeling diode in the high-speed zone; (2) the high back electromotive force in the high-speed zone causes impact damage to the components on the bus; (3) the motor output end in the high-speed zone generates unexpected large braking torque. Therefore, the control of the safe state of the motor controller seriously affects the performance, safety and life of the vehicle.

[0003] Chinese patent CN114435137A discloses an active short-circuit control method, apparatus, device, and medium for a motor controller. This method optimizes the conditions for the motor controller to enter the ASC state or the SPO (Safety Pulse Off) state by setting four thresholds, namely a temperature threshold and three speed thresholds, and comparing the actual speed value with the first, second, and third speed thresholds, as well as the actual temperature value with the temperature thresholds. Chinese patent CN112787309A discloses a circuit protection control method and system for a motor controller. This method calibrates a safe torque curve to determine two state switching points, compares the current speed threshold with the speed thresholds corresponding to the two switching points, and controls the motor controller to enter the ASC state or the SPO state based on the comparison results.

[0004] Therefore, in related technologies, the switching of the motor controller's safety state is usually judged based on the output torque and speed. Under different working conditions, the switching point is unchanged, and the corresponding speed is a constant value. The switching scenario of the safety state is too simple, and the output characteristics of the active protection ASC and the open circuit protection FW under different voltages are ignored, thereby generating unexpected torque, which will affect the safe operation of the motor controller. Summary of the Invention

[0005] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0006] In view of the shortcomings of the prior art described above, the present invention discloses a safety state control method, device, equipment and medium for a motor controller, which is used to solve the technical problem in the related art that the speed threshold is determined without considering the output characteristics of the active protection ASC and the open circuit protection FW at different voltages, which affects the safe operation of the motor controller.

[0007] In the first aspect, the present application provides a method for controlling the safety state of a motor controller, the method comprising: obtaining the current voltage and current speed of the motor; determining a target switching point representing the safety state of the motor controller based on the current voltage and a preset output torque curve; determining a first switching speed corresponding to the target switching point based on the preset output torque curve; comparing the current speed with the first switching speed; and adjusting the current safety state of the motor controller to a target safety state based on the first comparison result, the target safety state including an open circuit protection safety state and an active protection safety state.

[0008] In one embodiment of the present invention, obtaining the preset output torque curve diagram includes: if the motor is in the open circuit protection safety state, collecting multiple first output torques generated at different motor speeds corresponding to different motor voltages to obtain a first output torque set composed of the multiple first output torques; if the motor is in the active short circuit safety state, calculating multiple second output torques generated at different motor speeds to obtain a second output torque set composed of the multiple second output torques; establishing a motor speed-output torque coordinate system, drawing the first output torque curve of the open circuit protection safety state according to the first output torque set, and drawing the second output torque curve of the active short circuit protection state according to the second output torque set, wherein the first output torque curves are multiple; splicing the first output torque curve and the second output torque curve to generate the preset output torque curve diagram.

[0009] In one embodiment of the present invention, determining the target switching point representing the safety state of the motor controller based on the current voltage and in combination with a preset output torque curve diagram includes: obtaining the intersection of the first output torque curve and the second output torque curve, wherein there are multiple intersections; using the intersection curve formed by the intersections as the safety output torque curve; quantifying the relationship between the safety output torque curve and the motor speed to obtain a safety state switching curve; obtaining the target intersection of the first output torque curve corresponding to the current voltage and the safety state switching curve, and determining the target intersection as the target safety state switching point.

[0010] In one embodiment of the present invention, the target switching point representing the safety state of the motor controller is determined based on the current voltage and in combination with a preset output torque curve diagram, and further includes: if there are multiple target intersections, calculating the first peak feedback voltage based on the current reaction potential of the motor and the motor speed corresponding to each target intersection; performing a second comparison between the first peak feedback voltage and a preset withstand voltage value; among the first target intersections where the first peak feedback voltage is less than the preset withstand voltage value, selecting the first target intersection with a higher motor speed as the target safety state switching point; among the second target intersections where the first peak feedback voltage is greater than the preset withstand voltage value, selecting the corresponding second target intersection with a lower motor speed as the safety state switching point.

[0011] In one embodiment of the present invention, after selecting the second target intersection point with a lower motor speed as the safety state switching point, it also includes: calculating the second peak feedback voltage based on the motor speed corresponding to the second target intersection point with a lower motor speed and the current reaction potential; if the second peak feedback voltage is greater than the preset withstand voltage value, then using the preset withstand voltage value as the third peak feedback voltage; calculating the second safety state switching speed based on the third peak feedback voltage and the current reaction potential; and determining the point corresponding to the second safety state switching speed in the safety state switching curve as the target safety state switching point.

[0012] In one embodiment of the present invention, the calculation formula of the second output torque is: Among them, T e Indicates output torque; p n represents the number of motor pole pairs; ω represents the mechanical angular velocity; R s Motor stator winding; f Indicates the rotor flux; L d Indicates the d-axis inductance; L q represents the q-axis inductance.

[0013] In one embodiment of the present invention, before obtaining the current voltage and current speed of the vehicle, it also includes: monitoring the real-time status of the motor controller; when it is determined that the real-time status is a drive fault state, generating a drive fault signal based on the drive fault state; in response to the drive fault signal, triggering the motor controller to control the motor into a safety protection state.

[0014] In one embodiment of the present invention, adjusting the current state of the motor controller to the target safety state based on the comparison result includes: if the first comparison result is that the current speed is greater than or equal to the first safety state switching speed, then adjusting the current safety state of the motor controller to the active protection safety state; if the first comparison result is that the current speed is less than the first safety state switching speed, then adjusting the current safety state of the motor controller to the open circuit protection safety state.

[0015] In one embodiment of the present invention, obtaining the current voltage of the motor includes: collecting a first voltage signal in the battery pack output signal, a second voltage signal in the drive module output signal, and a third voltage signal in the power module output signal; processing the first voltage signal, the second voltage signal, and the third voltage signal to obtain the current voltage.

[0016] In second aspect, the present application provides a safety state control device for a motor controller, characterized in that the device includes: an acquisition module for acquiring the current voltage and current speed of the motor; a switching point determination module for determining a target switching point representing the safety state of the motor controller based on the current voltage and a preset output torque curve; a switching speed determination module for determining a first switching speed corresponding to the target switching point based on the preset output torque curve; a comparison module for comparing the current speed with the first switching speed; a target safety state determination module for adjusting the current safety state of the motor controller to a target safety state according to the first comparison result, the target safety state including an open circuit protection safety state and an active protection safety state.

[0017] In a third aspect, the present application provides an electronic device comprising: one or more processors; a storage device for storing one or more programs, which, when executed by one or more processors, enables the electronic device to implement the safe state control method of the motor controller described in the first aspect.

[0018] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor of a computer, the computer executes the safe state control method of the motor controller described in the first aspect.

[0019] As described above, the embodiments of the present invention provide a method, device, equipment, and medium for controlling the safety state of a motor controller, which have the following beneficial effects:

[0020] When a vehicle malfunctions and affects driving safety, triggering the safe state, the current motor voltage and speed are immediately obtained. A target switching point representing the safe state of the motor controller is determined based on the current voltage and a preset output torque curve. Different voltages correspond to different target switching points under the current operating conditions. Taking into account the output characteristics of the active safety circuit breaker (ASC) and open-circuit fuse (FW) at different voltages, the target switching point can be dynamically adjusted based on the voltage. A first switching speed corresponding to the target switching point is then determined based on the preset output torque curve. The current speed is compared with the first switching speed, and finally, based on the first comparison result, the current safe state of the motor controller is adjusted to the target safe state. By determining the target switching point for the safe state in real time based on the current voltage and output torque curves, the target switching point varies at different voltages. Combined with the current speed, the target safe state of the motor controller is rationally controlled and adjusted, minimizing the generation of unintended torque, preventing permanent demagnetization of the motor magnets, maintaining the motor's service life, and improving vehicle safety and controllability.

[0021] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, serving to explain the principles of the present application. It is obvious that the drawings described below are merely some embodiments of the present application, and a person of ordinary skill in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0023] Figure 1 is a diagram showing the working principle of ASC and FW according to an exemplary embodiment of the present application;

[0024] Figure 2 1 is a schematic diagram of an implementation environment of a safety state control device for a motor controller according to an exemplary embodiment of the present application;

[0025] Figure 3 is a flow chart of a safe state control method of a motor controller shown in an exemplary embodiment of the present application;

[0026] Figure 4 is a schematic diagram of a multi-voltage acquisition device shown in an exemplary embodiment of the present application;

[0027] Figure 5 yes Figure 3 Step S220 in the illustrated embodiment is a flow chart in an exemplary embodiment;

[0028] Figure 6 is a schematic diagram of a three-phase full-bridge passive rectification shown in an exemplary embodiment of the present application;

[0029] Figure 7 is a graph showing the relationship between the ASC output torque and current as the motor speed changes, according to an exemplary embodiment of the present application;

[0030] Figure 8 is a schematic diagram of transient three-phase current generated by an ASC according to an exemplary embodiment of the present application;

[0031] Figure 9 is a preset output torque curve diagram shown in an exemplary embodiment of the present application;

[0032] Figure 10 is another preset output torque curve diagram shown in an exemplary embodiment of the present application;

[0033] Figure 11 1 is a schematic structural diagram of a safety state control device for a motor controller according to an exemplary embodiment of the present application;

[0034] Figure 12 is a block diagram of an information configuration device for a vehicle controller shown in an exemplary embodiment of the present application;

[0035] Figure 13 This is a structural diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0036] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0037] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0038] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring the embodiments of the present invention.

[0039] First of all, it should be noted that for the drive system, the realization of ASC control or FW control is actually completed by controlling the motor controller power conversion module. Taking the Insulated Gate Bipolar Transistor (IGBT) as an example, see Figure 1 , Figure 1 FIG. 1 is a diagram showing the working principle of ASC and FW according to an exemplary embodiment of the present application. Figure 1 As shown in (a), when all six tubes of the upper and lower bridge arms of the IGBT module are disconnected, the inverter enters the passive rectification state and is in the FW safety state; Figure 1 As shown in (b), when the three tubes of the upper bridge arm of the IGBT module are turned on and the three tubes of the lower bridge arm are turned off, or as Figure 1 As shown in (c), when the three transistors in the upper bridge arm of the IGBT module are disconnected and the three transistors in the lower bridge arm are on, the module is in the ASC safe state. Therefore, the prerequisite for accurate ASC or FW control is to be able to correctly control the conduction and shutdown of the six upper and lower bridge arms of the three-phase power converter module.

[0040] In FW, all six upper and lower bridge arm switches are disconnected, disconnecting the motor from the motor controller. Under this condition, the motor can only be passively rectified via the reverse diode on the inverter bridge. The advantage of FW is that it does not generate large, unexpected torque, thereby not affecting the driver's control. However, if FW is performed during high-speed operation, the motor is in a weak magnetic state, resulting in a high back EMF. After passive rectification by the reverse diode, the voltage of this back EMF is greater than the battery voltage, thereby charging the DC-Link (capacitor) and increasing the bus voltage. This can affect other electronic components connected to the bus, such as IGBTs, and increase the risk of controller failure.

[0041] In ASC, the motor's stator windings form a closed loop with the IGBTs in the upper and lower arms. The back EMF energy generated by the motor is released through the stator windings, generating a corresponding braking torque at the motor output. This closed loop isolates the motor from external voltages and does not affect the bus voltage. In the ASC state, the current increases rapidly with increasing speed in the low-speed range, then decreases rapidly as speed increases, remaining stable in the high-speed range. The motor's output torque increases rapidly with increasing speed in the ultra-low-speed range, then decreases rapidly as speed increases, remaining stable in the high-speed range. At low speeds, ASC applies a significant braking torque to the motor rotor, enabling the motor to quickly stop and enter a safe state. However, this torque is unintended and can affect the driver's control of the vehicle. ASC also generates significant transient currents, resulting in a temperature rise that can affect the vehicle's thermal safety and the life of the motor's magnets.

[0042] Therefore, the control of the motor controller's safety state seriously affects the performance, safety, and life of the vehicle. The switching of the motor controller's safety state is usually judged based on the output torque and speed. Under different working conditions, the switching point is unchanged, and the corresponding speed is a constant value. The switching scenario of the safety state is too simple, and the output characteristics of the active protection ASC and the open circuit protection FW under different voltages are ignored, resulting in unexpected torque, which will affect the safe operation of the motor controller. It is necessary to propose a reasonable control strategy based on different voltages.

[0043] Therefore, see Figure 2 , Figure 2 FIG. 1 is a schematic diagram of an implementation environment of a safety state control device for a motor controller according to an exemplary embodiment of the present application. Figure 2 As shown, the implementation environment includes a vehicle 201 and a control device 202. The control device 202 is embedded in the vehicle 201 and is used to control the safety state of the motor controller. The control device 202 includes but is not limited to a vehicle system, an on-board computer, etc. The target switching point of the safety state is determined in real time through the current voltage and a preset output torque curve, so that the target switching point is different under different voltages. Combined with the current speed, the target safety state of the motor controller is reasonably controlled and adjusted, thereby minimizing the generation of unexpected torque, avoiding permanent demagnetization of the motor magnet, maintaining the service life of the motor, and improving the safety and controllability of the vehicle.

[0044] See Figure 3 , Figure 3 This is a flow chart of a safe state control method of a motor controller shown in an exemplary embodiment of the present application. This method can be applied to Figure 2It should be understood that the method can also be applied to other exemplary implementation environments and be specifically executed by devices in other implementation environments, and this embodiment does not limit the implementation environment to which the method is applicable.

[0045] like Figure 3 As shown, in an exemplary embodiment, the safety state control method of the motor controller includes at least steps S310 to S350, which are described in detail as follows:

[0046] Step S310: Acquire the current voltage and current speed of the motor.

[0047] In one embodiment, before obtaining the current voltage and current speed of the vehicle, the method further includes: monitoring the real-time status of the motor controller; when the real-time status is determined to be a drive fault state, generating a drive fault signal based on the drive fault state; and, in response to the drive fault signal, triggering the motor controller to control the motor into a safety protection state. Specifically, the motor controller needs to enter a safety state only when a vehicle fault occurs that affects driving safety.

[0048] Specifically, obtaining the current voltage of the motor includes: collecting a first voltage signal in the battery pack output signal, a second voltage signal in the drive module output signal, and a third voltage signal in the power module output signal; processing the first voltage signal, the second voltage signal, and the third voltage signal to obtain the current voltage.

[0049] See Figure 4 , Figure 4 FIG. 1 is a schematic diagram of a multi-voltage acquisition device according to an exemplary embodiment of the present application. Figure 4 As shown, the multi-voltage acquisition device includes at least a control device, a battery pack, and a battery management unit. The battery pack is the power output of the electric vehicle and provides a high-voltage input to the control device. The battery management unit refers to the BMS (Battery Management System), which collects the cell voltage, converts it into a total voltage, and outputs it to other modules through communication. The control device refers to the motor controller, which includes at least a microcontroller unit, a safety state processing unit, a drive control unit, and a power module. The microcontroller unit contains at least a memory and an actuator for storing control data information and executing the control of the motor controller; the safety state processing unit is electrically connected to the microcontroller unit, receives the microcontroller unit control signal, and outputs a comprehensive control signal to the drive control unit; the drive control unit is electrically connected to the safety state processing unit, receives the comprehensive control signal, and controls the power module to enter the safe state ASC or FW; the power module is electrically connected to the microcontroller unit, and the microcontroller unit collects the high-voltage input voltage of the power module.

[0050] exist Figure 4 In the embodiment, the microcontroller unit is electrically connected to the power module, receives the AD sampling signal, and processes it into a first voltage signal; is electrically connected to the drive control unit, receives the frequency sampling signal, and processes it into a second voltage signal; and is communicatively connected to the battery management unit BMS, and receives a third voltage signal. Preferably, the first voltage signal collected by the microcontroller unit can be a resistor divider, which is output to the microcontroller unit after passing through an isolated operational amplifier. Preferably, the safety state processing unit also receives signals from other modules, such as hardware overvoltage signals and power management signals, for comprehensive judgment with the control signals, and outputs a comprehensive control signal to the drive control unit, wherein the safety state processing unit can be expressed in the form of a logic gate circuit, and the drive control unit can be specifically expressed in the form of a drive control chip.

[0051] It should be noted that the above-mentioned processing of the AD sampling signal into the first voltage signal and the processing of the frequency sampling signal into the second voltage signal, the specific processing logic is not specifically described in this embodiment. This embodiment only describes that multiple redundant sampling of the current voltage can be achieved through a multi-voltage acquisition device to provide a stable, accurate and real-time current voltage (i.e., bus voltage).

[0052] Step S320 : determining a target switching point representing a safe state of the motor controller according to the current voltage and the preset output torque curve.

[0053] It should be noted that the target switching point serves as the switching point between ASC and FW, corresponding to the switching speed. Specifically, after the vehicle enters a safe state, when the current motor speed reaches a certain value, the motor controller's safe state should be controlled to ASC or FW. Furthermore, the preset output torque curve can be pre-stored in the microcontroller.

[0054] In one embodiment, see Figure 5 , Figure 5 yes Figure 3 Step S220 in the embodiment shown is a flow chart in an exemplary embodiment. Figure 5As shown, obtaining the preset output torque curve diagram includes at least steps S510 to S540, as follows: Step S510, if the motor is in an open-circuit protection safety state, collecting multiple first output torques generated at different motor speeds corresponding to different motor voltages to obtain a first output torque set consisting of multiple first output torques; Step S520, if the motor is in an active short-circuit safety state, calculating multiple second output torques generated at different motor speeds to obtain a second output torque set consisting of multiple second output torques; Step S530, establishing a motor speed-output torque coordinate system, drawing the first output torque curve of the open-circuit protection safety state according to the first output torque set, and drawing the second output torque curve of the active short-circuit protection state according to the second output torque set, wherein there are multiple first output torque curves; Step S540, splicing the first output torque curve and the second output torque curve to generate a preset output torque curve diagram.

[0055] It should be noted that, multiple first output torques generated by different motor speeds corresponding to different motor voltages are collected. For example, multiple first output torques generated by different motor speeds at 235V are collected, and then multiple first output torques generated by different motor speeds at 315V are collected, or multiple first output torques generated by different motor speeds at 350V are collected, and so on. In this way, multiple first output torque curves can be obtained based on different voltages. In addition, the voltage value range must conform to the range of the motor voltage.

[0056] like Figure 6 As shown, Figure 6 FIG. 1 is a schematic diagram of a three-phase full-bridge passive rectification circuit according to an exemplary embodiment of the present invention. Figure 6 As shown, six freewheeling diodes form a three-phase full-bridge rectifier circuit. The FW disconnects the controller from the motor by turning off the six switching tubes of the inverter bridge. Under this condition, the energy measured by the motor can only be passively rectified by the reverse diode on the inverter bridge. If the effective value of the back EMF does not exceed the bus voltage, the back EMF cannot turn on the diode and is in the cut-off state. The motor runs in an open circuit and the rotor can only rely on mechanical damping to stop. Therefore, the FW has two states: (1) Back EMF > bus voltage, the kinetic energy is discharged through passive rectification; (2) Back EMF < bus voltage, the kinetic energy of the motor is discharged through the ground or mechanical damping. When the back EMF is less than the bus voltage, the output torque is 0, which meets the minimum unexpected torque requirement.

[0057] See Figure 7 , Figure 7 FIG. 1 is a graph showing the relationship between the ASC output torque and current as the motor speed changes, according to an exemplary embodiment of the present application. Figure 7As shown, the horizontal axis is the motor speed, the left vertical axis is the current, and the right vertical axis is the ASC output torque. The curve with dots is the relationship curve of the current changing with the motor speed, and the curve with squares is the relationship curve of the ASC output torque changing with the motor speed. Figure 7 As can be seen in the figure, at low speeds, ASC will generate a large braking torque on the motor rotor. This braking torque can quickly stop the motor and enter a safe state, but this torque is unexpected and will affect the driver's control of the vehicle. At the same time, ASC will generate a large transient current, and the resulting temperature rise will affect the vehicle's thermal safety performance and the life of the motor's magnetic steel. Please refer to Figure 8 , Figure 8 FIG. 1 is a schematic diagram of transient three-phase current generated by an ASC, as shown in an exemplary embodiment of the present application. Figure 8 As shown, entering the ASC state will generate a very large transient current. Transient large current has two main hazards. One is permanent damage to components, and the other is irreversible demagnetization of the loaded motor magnets. Therefore, it is necessary to reasonably control the vehicle entering the ASC state.

[0058] In addition, it should be noted that the first output torque and the second output torque can be obtained by actually collecting the product from the high-voltage test bench, or by performing simulation calculations based on the parameters of the motor.

[0059] Specifically, in one embodiment, the calculation formula of the second output torque is: Among them, T e Indicates output torque; p n represents the number of motor pole pairs; ω represents the mechanical angular velocity; R s Motor stator winding; f Indicates the rotor flux; L d Indicates the d-axis inductance; L q represents the q-axis inductance.

[0060] In this embodiment, the calculation formula of the second output torque may vary based on the motor speed. Specifically, when the motor speed is very low (ie ), the calculation formula is When the motor speed is very high (i.e. ) is calculated as

[0061] See Figure 9 , Figure 9 This is a preset output torque curve diagram shown in an exemplary embodiment of the present application. Figure 9As shown, the horizontal axis represents the motor speed and the vertical axis represents the output torque; curve 1 represents the relationship between the motor torque and the motor speed in the ASC state; curve 2 represents the relationship between the motor torque and the motor speed at 235V in the FW state; curve 3 represents the relationship between the motor torque and the motor speed at 315V in the FW state; curve 4 represents the relationship between the motor torque and the motor speed at 350V in the FW state; curve 5 represents the relationship between the motor torque and the motor speed at 410V in the FW state.

[0062] In one embodiment, a target switching point representing the safety state of a motor controller is determined based on the current voltage and a preset output torque curve diagram, including: obtaining the intersection of a first output torque curve and a second output torque curve, where there are multiple intersections; using the intersection curve formed by the intersections as a safety output torque curve; quantifying the relationship between the safety output torque curve and the motor speed to obtain a safety state switching curve; obtaining the target intersection of the first output torque curve corresponding to the current voltage and the safety state switching curve, and determining the target intersection as the target safety state switching point.

[0063] For example, see Figure 9 The first output torque curve (curves 2, 3, 4, and 5) and the second output torque curve (curve 1) form four intersection points, representing the safe state switching points at voltages of 235V, 315V, 350V, and 410V, respectively. The intersection curve formed by these four intersection points is used as the safe output torque curve. The relationship between the safe output torque curve and motor speed is quantified to obtain the safe state switching curve. Assuming the current voltage is 235V, the intersection of curves 2 and 1 is the target safe state switching point.

[0064] In another embodiment of the present application, the intersection of the first output torque curve and the second output torque curve can be added or deleted according to actual needs, and the output torque characteristics at different voltages and the advantages and disadvantages of the safety state at different speed ranges can be dynamically adjusted as the voltage fluctuates.

[0065] See Figure 10 , Figure 10 is another preset output torque curve diagram shown in an exemplary embodiment of the present application. Figure 10As shown, if the output torque data of FW under high density and different voltages are obtained, curves C1, C2, C3...Cn can be obtained; the output torque data of ASC can be obtained, curve Ck; the intersection of Ck and any curve among curves C1~Cn constitutes the safe output torque T(n,V) under the corresponding voltage, where n represents the motor speed and V represents the motor voltage; the intersection points of curves C1~Cn and curve Ck are k1, k2, k3...kn respectively, and the curve k1kn formed by the intersection points is the safe output torque curve Fx=T(n,V); the relationship between the safe output torque curve Fx and the motor speed is quantified to obtain the safe state switching curve and write it into the microcontroller component; when the vehicle is triggered to enter the safe state, the multi-voltage acquisition device obtains the current voltage and dynamically determines the switching point of the safe state based on the current voltage. If the switching point is k1, then the switching speed can be determined to be the speed corresponding to point n1.

[0066] In one embodiment, the target switching point representing the safety state of the motor controller is determined based on the current voltage and a preset output torque curve diagram, and also includes: if there are multiple target intersections, calculating the first peak feedback voltage based on the current reaction potential of the motor and the motor speed corresponding to each target intersection; performing a second comparison between the first peak feedback voltage and the preset withstand voltage value; among the first target intersections where the first peak feedback voltage is less than the preset withstand voltage value, selecting the first target intersection with a higher motor speed as the target safety state switching point; among the second target intersections where the first peak feedback voltage is greater than the preset withstand voltage value, selecting the corresponding second target intersection with a lower motor speed as the safety state switching point.

[0067] It should be noted that if the density of motor voltage sampling points is high, the same safe torque may correspond to n speed switching points (target intersection points). In this case, the target switching point will be determined based on the comparison result of the peak reverse voltage and the preset withstand voltage value. Taking IGBT as an example, the preset withstand voltage value is the withstand voltage value of the insulated gate bipolar transistor. In addition, the peak reverse voltage is calculated as follows: Peak reverse voltage = motor back potential * motor speed * 1.4, where the motor speed is the motor speed corresponding to the target intersection point.

[0068] Specifically, in one embodiment, after selecting the second target intersection point with a lower motor speed as the safe state switching point, it also includes: calculating the second peak feedback voltage based on the motor speed corresponding to the second target intersection point with a lower motor speed and the current reaction potential; if the second peak feedback voltage is greater than the preset withstand voltage value, the preset withstand voltage value is used as the third peak feedback voltage; the second safe state switching speed is calculated based on the third peak feedback voltage and the current reaction potential; and the point corresponding to the second safe state switching speed in the safe state switching curve is determined as the target safe state switching point.

[0069] Step S230: determining a first switching speed corresponding to the target switching point based on a preset output torque curve.

[0070] Please continue to see Figure 10 In the preset output torque curve, if k1 is determined as the target switching point, the speed corresponding to point n1 is the switching speed.

[0071] Step S240: Compare the current rotation speed with the first switching rotation speed.

[0072] Step S250 : adjusting the current safety state of the motor controller to a target safety state according to the first comparison result. The target safety state includes an open circuit protection safety state and an active protection safety state.

[0073] Specifically, the current state of the motor controller is adjusted to the target safety state according to the comparison result, including: if the first comparison result is that the current speed is greater than or equal to the first safety state switching speed, the current safety state of the motor controller is adjusted to the active protection safety state; if the first comparison result is that the current speed is less than the first safety state switching speed, the current safety state of the motor controller is adjusted to the open circuit protection safety state.

[0074] The motor controller safety state control method provided in the above embodiment, when a vehicle malfunctions and affects driving safety, triggering the safe state, immediately obtains the current voltage and current speed of the motor. Based on the current voltage and a preset output torque curve, a target switching point representing the safe state of the motor controller is determined. Different voltages under current operating conditions correspond to different target switching points. Taking into account the output characteristics of the active safety circuit breaker (ASC) and the open-circuit protection (FW) at different voltages, the target switching point can be dynamically adjusted based on the voltage. A first switching speed corresponding to the target switching point is then determined based on the preset output torque curve. The current speed is compared with the first switching speed. Finally, based on the first comparison result, the current safe state of the motor controller is adjusted to the target safe state. By determining the target switching point of the safe state in real time based on the current voltage and output torque curve, the target switching point varies at different voltages. Combined with the current speed, the target safe state of the motor controller is rationally controlled and adjusted, minimizing the generation of unintended torque, preventing permanent demagnetization of the motor magnets, maintaining the motor's service life, and improving the safety and controllability of the vehicle.

[0075] See Figure 11 , Figure 11 FIG. 1 is a schematic diagram showing a safety state control device of a motor controller according to an exemplary embodiment of the present application. Figure 11 As shown in the figure, the structural diagram includes a battery management controller, a CAN interface, a control module, a drive module and a power module. The details are as follows:

[0076] The battery management controller is the acquisition control unit of the battery pack. It communicates with the voltage acquisition unit in the control module through the CAN interface and transmits voltage 1 through the communication network.

[0077] The control module includes a motor control unit and a voltage acquisition unit.

[0078] The voltage acquisition unit is communicatively connected to the voltage acquisition unit, receives the voltage signal 1 of the battery pack, is electrically connected to the drive unit in the drive module, receives the voltage signal 2, preferably, the voltage signal can be a frequency signal, the drive unit collects the voltage signal and transmits information in a PWM manner, is indirectly electrically connected to the high-voltage input of the power module, receives the voltage signal 3, preferably, the voltage signal can be an analog sampling signal, collects the bus voltage through a resistor divider, and is sent to the voltage acquisition unit through an isolation operational amplifier.

[0079] Preferably, the voltage acquisition unit collects multiple sets of voltages for redundant sampling, ensuring real-time and accurate voltages and meeting the prerequisites for dynamic control. Depending on the actual configuration, voltage sampling can be performed from one, two, three, or even more sources, and the bus voltage can also be calculated by reverse engineering the real-time motor data.

[0080] The motor control unit includes a microcontroller component and a logic processing component. The microcontroller component can be specifically regarded as a single-chip microcomputer MCU (Micro Controller Uni, micro control unit), which contains memory and actuators, stores control data information, and executes related control information to output to the logic processing component. In the embodiment, the specific information stored for execution includes voltage signals, safety status control information, etc. The logic processing component is electrically connected to the microcontroller component and receives the control information of the microcontroller component. In this embodiment, the logic processing component can be specifically regarded as a logic gate circuit, which receives various signal inputs for logical judgment. Preferably, the logic processing component can also receive motor speed or motor voltage, etc., and perform logical judgment in combination with the safety status control signal input of the microcontroller component. The logic processing component is electrically connected to the programmable logic device in the drive module, and the safety status control signal after comprehensive judgment is output to the programmable logic device.

[0081] The driver module includes a programmable logic device (PLD) and a driver unit. The programmable logic device may be a CPLD (Complex Programmable Logic Device), or other types of programmable logic devices in other embodiments. The driver unit may be an IGBT driver unit, or other types of driver units in other embodiments.

[0082] The power module contains 6 IGBTs, and the upper / lower bridge arms are composed of 3 IGBTs. It receives the control signal of the drive unit and performs the corresponding work of the IGBT.

[0083] See Figure 12 , Figure 12 This is a block diagram of a safety state control device for a motor controller according to an exemplary embodiment of the present application. Figure 2 The implementation environment shown is shown. It should be understood that the device can also be applied to other exemplary implementation environments, and this embodiment does not limit the implementation environment to which the device is applicable.

[0084] like Figure 12 As shown, in an exemplary embodiment, the safety state control device of the motor controller includes at least an acquisition module 1210, a switching point determination module 1220, a switching speed determination module 1230, a comparison module 1240, and a target safety state determination module 1250, which are described in detail as follows:

[0085] An acquisition module 1210 is used to acquire the current voltage and current speed of the motor;

[0086] A switching point determination module 1220 is configured to determine a target switching point representing a safe state of the motor controller based on the current voltage and a preset output torque curve;

[0087] a switching speed determining module 1230 for determining a first switching speed corresponding to a target switching point based on a preset output torque curve;

[0088] A comparison module 1240 is configured to compare the current rotation speed with the first switching rotation speed;

[0089] The target safety state determination module 1250 is configured to adjust the current safety state of the motor controller to a target safety state according to the first comparison result. The target safety state includes an open circuit protection safety state and an active protection safety state.

[0090] It should be noted that the safety state control device of the motor controller provided in the above embodiment and the safety state control method of the motor controller provided in the above embodiment belong to the same concept, and the content of the operations performed by each module has been described in detail in the method embodiment and will not be repeated here.

[0091] See Figure 13 , Figure 13 This is a structural diagram of an electronic device provided by an embodiment of the present application. Figure 13 The following is a schematic diagram showing the structure of a computer system suitable for implementing an electronic device according to an embodiment of the present application. Figure 13The computer system 1300 of the electronic device shown is only an example and should not limit the functions and scope of use of the embodiments of the present application.

[0092] like Figure 13 As shown, computer system 1300 includes a central processing unit (CPU) 1301, which can perform various appropriate actions and processes according to programs stored in read-only memory (ROM) 1302 or programs loaded from storage unit 1308 into random access memory (RAM) 1303, such as executing the methods in the above embodiments. Various programs and data required for system operation are also stored in RAM 1303. CPU 1301, ROM 1302, and RAM 1303 are connected to each other via bus 1304. Input / output (I / O) interface 1305 is also connected to bus 1304.

[0093] The following components are connected to the I / O interface 1305: an input section 1306 including a keyboard, a mouse, and the like; an output section 1307 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and speakers; a storage section 1308 including a hard disk; and a communication section 1309 including a network interface card such as a LAN (Local Area Network) card or a modem. The communication section 1309 performs communication processing via a network such as the Internet. A drive 1313 is also connected to the I / O interface 1305 as needed. Removable media 1311, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 1313 as needed, so that computer programs read from the removable media can be installed in the storage section 1308 as needed.

[0094] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 1309, and / or installed from a removable medium 1311. When the computer program is executed by the central processing unit (CPU) 1301, the various functions defined in the system of the present application are executed.

[0095] It should be noted that the computer-readable medium shown in the embodiments of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable computer program. This propagated data signal can take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. A computer program embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0096] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. Each box in the flowchart or block diagram can represent a module, program segment, or part of the code, and the above-mentioned module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the boxes can also occur in an order different from that marked in the accompanying drawings. For example, two boxes shown in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or can be implemented using a combination of dedicated hardware and computer instructions.

[0097] The units involved in the embodiments of the present invention may be implemented in software or hardware, and the units described may also be provided in a processor. In some cases, the names of these units do not limit the units themselves.

[0098] The present invention also provides a computer-readable storage medium having a computer program stored thereon. When executed by a computer processor, the computer program causes the computer to execute the above-described safe state control method for a motor controller. The computer-readable storage medium may be included in the electronic device described in the above embodiments, or may exist independently and not be incorporated into the electronic device.

[0099] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, any equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A safety state control method for a motor controller, characterized in that: The method comprises: Get the current voltage and current speed of the motor; Determining a target switching point representing a safe state of the motor controller according to the current voltage and a preset output torque curve; determining a first switching speed corresponding to the target switching point based on the preset output torque curve; Comparing the current speed with the first switching speed to obtain a first comparison result; adjusting the current safety state of the motor controller to a target safety state according to the first comparison result, the target safety state including an open circuit protection safety state and an active short circuit protection safety state; The adjusting the current safety state of the motor controller to the target safety state based on the first comparison result includes: if the first comparison result is that the current speed is greater than or equal to the first switching speed, adjusting the current safety state of the motor controller to the active short-circuit protection safety state; if the first comparison result is that the current speed is less than the first switching speed, adjusting the current safety state of the motor controller to the open-circuit protection safety state.

2. The safe state control method of the motor controller according to claim 1, characterized in that: The acquisition of the preset output torque curve diagram includes: If the motor is in the open circuit protection safety state, collecting a plurality of first output torques generated at different motor speeds corresponding to different motor voltages to obtain a first output torque set consisting of the plurality of first output torques; If the motor is in the active short-circuit protection safety state, calculating a plurality of second output torques generated at different motor speeds to obtain a second output torque set consisting of the plurality of second output torques; Establishing a motor speed-output torque coordinate system, drawing a first output torque curve of the open circuit protection safety state according to the first output torque set, and drawing a second output torque curve of the active short circuit protection safety state according to the second output torque set, wherein the first output torque curves are multiple; The first output torque curve and the second output torque curve are spliced ​​together to generate the preset output torque curve graph.

3. The safe state control method of the motor controller according to claim 2, characterized in that: The determining of a target switching point representing a safe state of the motor controller according to the current voltage and a preset output torque curve diagram includes: Obtaining a plurality of intersection points of the first output torque curve and the second output torque curve; using an intersection curve formed by the intersection points as a safe output torque curve; Quantifying the relationship between the safe output torque curve and the motor speed to obtain a safe state switching curve; A target intersection point between the first output torque curve corresponding to the current voltage and the safety state switching curve is obtained, and the target intersection point is determined as the target safety state switching point.

4. The safe state control method of the motor controller according to claim 3, characterized in that: The step of determining a target switching point representing a safe state of the motor controller based on the current voltage and a preset output torque curve diagram further includes: If there are multiple target intersection points, the first peak feedback voltage is calculated according to the current reaction potential of the motor and the motor speed corresponding to each target intersection point; Performing a second comparison on the first peak feedback voltage and a preset withstand voltage value; Among the first target intersection points where the first peak feedback voltage is less than the preset withstand voltage value, selecting a first target intersection point where the motor speed is higher as the target safety state switching point; Among the second target intersection points where the first peak feedback voltage is greater than the preset withstand voltage value, a second target intersection point where the corresponding motor speed is lower is selected as the safe state switching point.

5. The safe state control method of the motor controller according to claim 4, characterized in that: After selecting the second target intersection point with a lower motor speed as the safe state switching point, the method further includes: Calculating a second peak feedback voltage according to the motor speed corresponding to the second target intersection point with a lower motor speed and the current reaction potential; If the second peak feedback voltage is greater than the preset withstand voltage, the preset withstand voltage is used as the third peak feedback voltage; Calculate and obtain a second safety state switching speed according to the third peak reverse injection voltage and the current reverse potential; The point corresponding to the second safety state switching speed in the safety state switching curve is determined as the target safety state switching point.

6. The safe state control method of the motor controller according to claim 4, characterized in that: The calculation formula of the second output torque is: in, Indicates output torque; represents the number of motor pole pairs; ω represents the mechanical angular velocity; Motor stator winding; represents the rotor flux; represents the d-axis inductance; represents the q-axis inductance.

7. The safe state control method of a motor controller according to claim 1, characterized in that: Before obtaining the current voltage and current speed of the motor, the method further includes: Monitoring the real-time status of the motor controller; When it is determined that the real-time state is a driving fault state, generating a driving fault signal based on the driving fault state; In response to the driving fault signal, the motor controller is triggered to control the motor into a safety protection state.

8. The safety state control method of a motor controller according to any one of claims 1 to 7, characterized in that: The obtaining of the current voltage of the motor includes: Collecting a first voltage signal from a battery pack output signal, a second voltage signal from a drive module output signal, and a third voltage signal from a power module output signal; The first voltage signal, the second voltage signal, and the third voltage signal are processed to obtain the current voltage.

9. A safety state control device for a motor controller, characterized in that: The device comprises: The acquisition module is used to obtain the current voltage and current speed of the motor; a switching point determination module, configured to determine a target switching point representing a safety state of the motor controller according to the current voltage and a preset output torque curve; a switching speed determining module, configured to determine a first switching speed corresponding to the target switching point based on the preset output torque curve; a comparison module, configured to compare the current speed with the first switching speed to obtain a first comparison result; a target safety state determination module, configured to adjust the current safety state of the motor controller to a target safety state according to the first comparison result, wherein the target safety state includes an open circuit protection safety state and an active short circuit protection safety state; The target safety state determination module is specifically used to adjust the current safety state of the motor controller to the active short-circuit protection safety state if the first comparison result is that the current speed is greater than or equal to the first switching speed; if the first comparison result is that the current speed is less than the first switching speed, adjust the current safety state of the motor controller to the open-circuit protection safety state.

10. An electronic device, characterized in that: include: one or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, enables the electronic device to implement the safe state control method of the motor controller as described in any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that Computer-readable instructions are stored thereon, and when the computer-readable instructions are executed by a processor of a computer, the computer is caused to execute the safe state control method of the motor controller according to any one of claims 1 to 8.

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