Control method and device of motor controller, electronic equipment and storage medium
By judging the back potential of the motor and rotor temperature in the motor controller, calculating the gradient duty cycle based on the upper limit of the system operation voltage, and implementing a flexible gradient three-phase active short circuit strategy, the problem of overcurrent or overvoltage in the existing technology is solved, and the motor demagnetization avoidance and system safety improvement is achieved.
Patent Information
- Application Number
- CN202411917719.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-03-28
AI Technical Summary
In the event of serious failure, existing motor controllers adopt the gradient ASC method with direct three-phase active short circuit state or fixed slope, which respectively have problems such as overcurrent damage to the power module or motor demagnetization, and overvoltage damage to the motor controller.
When the main relay of the motor is closed, it is determined whether the back potential of the motor is greater than the battery voltage, and when the back potential is greater than the battery voltage, it is determined whether the rotor temperature is greater than the preset temperature threshold. If the temperature is above the threshold, the gradient duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operation voltage, and a flexible gradient three-phase active short-circuit strategy is implemented to limit the voltage of the motor controller within the upper limit of the system operation voltage.
While using three-phase active short circuit to avoid demagnetization of the motor, the system's safety and reliability are improved by limiting the voltage of the motor controller and avoiding overvoltage damage to the motor controller or battery.
Smart Images
Figure CN119727527A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of automotive electronics and electrical engineering, and in particular to a control method, device, electronic equipment and storage medium for a motor controller. Background Art
[0002] At present, the mainstream practice in the industry is to use direct three-phase active short circuit (DASC) or a fixed slope gradual ASC method (GASC) when the motor controller fails seriously. However, they have the following disadvantages:
[0003] When the DASC method is used, the moment the motor controller directly enters the three-phase active short-circuit state (ASC), a large current exceeding 1.5 times the peak current will be generated, which can easily cause overcurrent damage to the power module or demagnetization of the motor permanent magnet.
[0004] By adopting the GASC method, the duty cycle of the ASC is controlled to enable the motor controller to achieve a gradual three-phase active short-circuit state, which can suppress the current value of the ASC to a limited extent. However, many special working conditions can easily cause the electronic control voltage to rise, and overvoltage may damage the motor controller or battery. Summary of the invention
[0005] The purpose of the embodiments of the present application is to provide a control method, device, electronic device and storage medium for a motor controller, so as to avoid overvoltage damage to the motor controller or battery while avoiding motor demagnetization.
[0006] In a first aspect, the present invention provides a control method for a motor controller, the method comprising:
[0007] When the main relay of the motor is closed, it is determined whether the motor back electromotive force is greater than the battery voltage;
[0008] When the motor back electromotive force is greater than the battery voltage, it is determined whether the motor rotor temperature is greater than a preset temperature threshold; if the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state.
[0009] The method of the present application can determine whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed, and further can determine whether the motor rotor temperature is greater than a preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state, and further while utilizing the three-phase active short circuit to avoid motor demagnetization, the voltage of the motor controller is limited to below the upper limit of the system operating voltage to avoid overvoltage damage to the motor controller or the battery.
[0010] In an optional embodiment, the method further comprises:
[0011] When the main relay of the motor is disconnected, it is determined whether the motor speed is greater than the preset speed threshold. If the motor speed is greater than the preset speed threshold, the power modules of the motor controller are controlled to be completely shut down for 125us, and a direct three-phase active short-circuit strategy is executed after 125us to limit the maximum current of the motor controller.
[0012] This optional implementation can determine whether the motor speed is greater than a preset speed threshold when the main relay of the motor is disconnected, and if the motor speed is greater than the preset speed threshold, it can control all power modules of the motor controller to be turned off for 125us, and execute a direct three-phase active short-circuit strategy after 125us to limit the maximum power of the motor controller.
[0013] In an optional embodiment, the method further comprises:
[0014] When the motor rotor temperature is lower than the preset temperature threshold, all power modules of the motor controller are controlled to be turned off for 125us, and a direct three-phase active short-circuit strategy is executed after 125us to limit the maximum current of the motor controller.
[0015] This optional implementation can control all power modules of the motor controller to be shut down for 125us when the motor rotor temperature is lower than the preset temperature threshold, and execute a direct three-phase active short-circuit strategy after 125us to limit the maximum current of the motor controller.
[0016] In an optional implementation manner, the step of calculating the gradual duty cycle of the three-phase active short-circuit state based on the system operating voltage upper limit includes:
[0017] Calculating a time constant of the gradually changing duty cycle based on the motor back EMF and the battery voltage;
[0018] The gradually changing duty cycle is calculated based on a time constant of the gradually changing duty cycle and an upper limit of a system operating voltage, wherein:
[0019] G(s)=1 / (tao*s+1);
[0020] tao=α*(V3-V2) / (V1-V3);
[0021] Among them, tao represents the time constant of the gradual duty cycle, G(s) represents the gradual duty cycle, s represents time, α is the calibration coefficient, V1 represents the motor back electromotive force, V2 represents the battery voltage, and V3 represents the upper limit of the system operating voltage, which is determined based on the design parameters of the battery and the parameters of the motor controller.
[0022] This optional implementation can accurately calculate the gradual duty cycle through the above calculation formula, and make the voltage during the gradual active short circuit process less than the upper limit of the system operating voltage.
[0023] In an optional embodiment, the method further comprises:
[0024] The motor back EMF is calculated based on the motor flux and the motor speed.
[0025] This optional implementation can calculate the motor back EMF based on the motor's flux and motor speed.
[0026] In an optional embodiment, the method further comprises:
[0027] When the main relay of the motor is disconnected and the motor speed is less than the preset speed threshold, all power modules controlling the motor controller are turned off.
[0028] This optional implementation manner can control all power modules of the motor controller to be turned off when the main relay of the motor is disconnected and the motor speed is less than the preset speed threshold.
[0029] In an optional embodiment, the method further comprises:
[0030] When the main relay of the motor is closed and the back electromotive force of the motor is less than the battery voltage, all power modules controlling the motor controller are turned off.
[0031] This optional implementation can control all power modules of the motor controller to be turned off when the main relay of the motor is closed and the back electromotive force of the motor is less than the battery voltage.
[0032] In a second aspect, the present invention provides a control device for a motor controller, the device comprising:
[0033] A first judgment module is used to judge whether the back electromotive force of the motor is greater than the battery voltage when the main relay of the motor is closed;
[0034] The second judgment module is used to judge whether the motor rotor temperature is greater than a preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, a gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state.
[0035] The device of the present application can determine whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed, and further can determine whether the motor rotor temperature is greater than the preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state, and further while utilizing the three-phase active short circuit to avoid motor demagnetization, the voltage of the motor controller is limited to below the upper limit of the system operating voltage to avoid overvoltage damage to the motor controller or the battery.
[0036] In a third aspect, the present invention provides an electronic device, comprising:
[0037] Processor; and
[0038] The memory is configured to store machine-readable instructions, and when the instructions are executed by the processor, the control method of the motor controller as described in any one of the aforementioned embodiments is executed.
[0039] The electronic device of the present application can determine whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed by executing the control method of the motor controller, and further determine whether the motor rotor temperature is greater than a preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state, thereby avoiding overvoltage damage to the motor controller or the battery by limiting the voltage of the motor controller to below the upper limit of the system operating voltage while utilizing the three-phase active short circuit to avoid motor demagnetization.
[0040] In a fourth aspect, the present invention provides a storage medium storing a computer program, wherein the computer program is executed by a processor to implement a control method for a motor controller as described in any one of the aforementioned embodiments.
[0041] The storage medium of the present application can determine whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed by executing the control method of the motor controller, and further determine whether the motor rotor temperature is greater than a preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state, thereby avoiding overvoltage damage to the motor controller or the battery by limiting the voltage of the motor controller to below the upper limit of the system operating voltage while utilizing the three-phase active short circuit to avoid motor demagnetization. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0043] Figure 1 It is a flow chart of a control method of a motor controller disclosed in an embodiment of the present application;
[0044] Figure 2is a flow chart of another control method of a motor controller disclosed in an embodiment of the present application;
[0045] Figure 3 is a structural schematic diagram of a control device of a motor controller disclosed in an embodiment of the present application;
[0046] Figure 4 It is a structural schematic diagram of an electronic device disclosed in an embodiment of the present application. DETAILED DESCRIPTION
[0047] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.
[0048] Embodiment 1
[0049] See also Figure 1 , Figure 1 is a flow chart of a control method of a motor controller disclosed in an embodiment of the present application, such as Figure 1 As shown, the method of the embodiment of the present application includes the following steps:
[0050] 101. When the main relay of the motor is closed, determine whether the motor back electromotive force is greater than the battery voltage;
[0051] 102. When the motor back electromotive force is greater than the battery voltage, determine whether the motor rotor temperature is greater than the preset temperature threshold. If the motor rotor temperature is greater than the preset temperature threshold, calculate the gradual duty cycle of the three-phase active short-circuit state based on the upper limit of the system operating voltage, and execute a flexible gradual three-phase active short-circuit strategy based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state.
[0052] The method of the embodiment of the present application can determine whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed, and further can determine whether the motor rotor temperature is greater than the preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state, and further while utilizing the three-phase active short circuit to avoid motor demagnetization, the voltage of the motor controller is limited to below the upper limit of the system operating voltage to avoid overvoltage damage to the motor controller or the battery.
[0053] In the embodiment of the present application, as an optional implementation, the method of the embodiment of the present application further includes the following steps:
[0054] When the main relay of the motor is disconnected, it is determined whether the motor speed is greater than the preset speed threshold. If the motor speed is greater than the preset speed threshold, the power modules of the motor controller are all controlled to be turned off for 125us, and a direct three-phase active short-circuit strategy is executed after 125us to limit the maximum current of the motor controller.
[0055] This optional implementation can determine whether the motor speed is greater than a preset speed threshold when the main relay of the motor is disconnected. If the motor speed is greater than the preset speed threshold, the power modules of the motor controller can be controlled to be completely shut down for 125us, and a direct three-phase active short-circuit strategy can be executed after 125us to limit the maximum power of the motor controller.
[0056] In the embodiment of the present application, as an optional implementation, the method of the embodiment of the present application further includes the following steps:
[0057] When the motor rotor temperature is lower than the preset temperature threshold, all power modules of the motor controller are shut down for 125us, and a direct three-phase active short-circuit strategy is executed after 125us to limit the maximum current of the motor controller.
[0058] This optional implementation can control all power modules of the motor controller to shut down for 125us when the motor rotor temperature is lower than a preset temperature threshold, and execute a direct three-phase active short-circuit strategy after 125us to limit the maximum current of the motor controller.
[0059] In the embodiment of the present application, as an optional implementation, the step of calculating the gradual duty cycle of the three-phase active short-circuit state based on the upper limit of the system operating voltage includes the following sub-steps:
[0060] Calculate the time constant of the gradual duty cycle based on the motor back EMF and the battery voltage;
[0061] The gradual duty cycle is calculated based on the time constant of the gradual duty cycle and the upper limit of the system operating voltage, where:
[0062] G(s)=1 / (tao*s+1);
[0063] tao=α*(V3-V2) / (V1-V3);
[0064] Wherein, tao represents the time constant of the gradual duty cycle, G(s) represents the gradual duty cycle, s represents time, α represents the calibration coefficient, V1 represents the motor back electromotive force, V2 represents the battery voltage, and V3 represents the upper limit of the system operating voltage, which is determined based on the design parameters of the battery and the parameters of the motor controller.
[0065] This optional implementation can accurately calculate the gradual duty cycle based on the system operating voltage upper limit through the above calculation formula, and make the voltage during the gradual active short circuit process less than the system operating voltage upper limit.
[0066] In the above optional implementation, the original transfer function used to calculate the duty cycle is G(s)=1 / (α*s+1). The duty cycle obtained based on the calculation formula can realize a gradual change of the duty cycle with a fixed slope, and then control the gradual active short circuit of the switch tube in the inverter based on the gradual duty cycle.
[0067] Furthermore, in the calculation formula G(s)=1 / (α*s+1), there is no calculation based on the battery voltage, back electromotive force and the upper limit of the system operating voltage. Therefore, the duty cycle cannot be adjusted according to the battery voltage, back electromotive force and the upper limit of the system operating voltage. As a result, during the gradual active short circuit process, the voltage rise caused by the active short circuit may exceed the upper limit of the system operating voltage, thereby damaging the battery and the inverter.
[0068] Furthermore, on the basis of the calculation formula G(s)=1 / (α*s+1), the battery voltage, the upper limit of the system operating voltage and the motor back EMF are introduced, and then the calculation formula G(s)=1 / (α*(V3-V2) / (V1-V3)*s+1) is obtained, wherein V1 represents the motor back EMF, V2 represents the battery voltage, and V3 represents the upper limit of the system operating voltage. When calculating the duty cycle, the calculation formula G(s)=1 / (α*(V3-V2) / (V1-V3)*s+1) introduces the motor back EMF, battery voltage and the upper limit of the system operating voltage, that is, the duty cycle is affected by the motor back EMF, battery voltage and the upper limit of the system operating voltage. Among them, through actual tests, the calculation formula G(s)=1 / (α*(V3-V2) / (V1-V3)*s+1) can always limit the voltage in the progressive active short circuit process to below the upper limit of the system operating voltage, thereby avoiding the voltage rise caused by the active short circuit from damaging the battery and inverter.
[0069] In the embodiment of the present application, as an optional implementation, the method of the embodiment of the present application further includes the following steps:
[0070] The motor back EMF is calculated based on the motor's flux linkage and motor speed.
[0071] This optional implementation can calculate the motor back EMF based on the motor's flux and motor speed.
[0072] In the embodiment of the present application, as an optional implementation, the method of the embodiment of the present application further includes the following steps:
[0073] When the main relay of the motor is disconnected and the motor speed is less than the preset speed threshold, all power modules controlling the motor controller are turned off.
[0074] This optional implementation can control all power modules of the motor controller to shut down when the main relay of the motor is disconnected and the motor speed is less than a preset speed threshold.
[0075] In the embodiment of the present application, as an optional implementation, the method of the embodiment of the present application further includes the following steps:
[0076] When the main relay of the motor is closed and the motor back EMF is less than the battery voltage, the power modules controlling the motor controller are all turned off.
[0077] This optional implementation can control all power modules of the motor controller to shut down when the main relay of the motor is closed and the back electromotive force of the motor is less than the battery voltage.
[0078] For the embodiments of this application, as an example, please refer to Figure 2 , Figure 2 FIG. 1 is a flow chart of another control method of a motor controller disclosed in an embodiment of the present application. Figure 2 As shown:
[0079] The motor controller obtains the motor speed n0 through its own speed sensor, the motor controller voltage V0 through the voltage sensor, the motor rotor temperature T0 through rotor temperature estimation, and the vehicle battery voltage V2 and the main relay status of the battery supplying power to the electric drive through CAN communication. According to the design parameters of the battery and the electric drive, the maximum operating voltage V3 is obtained.
[0080] Furthermore, according to the magnetic flux Ψ of the motor, the current motor back electromotive force V1 = n0*Ψ is calculated.
[0081] Further, the state of the battery main relay is determined. If the main relay is disconnected, then step 4 is executed. If the main relay is closed, then jump to step 5.
[0082] Further, determine whether the motor speed n0 is greater than n2. If n0≥n2, turn off the tube (FW) for 125us first, and then enter ASC directly; if n0<n2, turn off the tube (FW) directly. Then jump to the last step;
[0083] Further, determine whether the current motor back electromotive force V1 is greater than the current battery voltage V2. If V1<V2, then directly turn off the tube (FW). If V1≥V2, then jump to step 6;
[0084] Further, determine whether the motor rotor temperature T0 is greater than the motor magnetic steel demagnetization temperature T1. If T0<T1, then turn off the tube (FW) for 125us and then enter direct ASC. If T0≥T1, then jump to step 7;
[0085] Further, according to the current motor back electromotive force V1 and battery voltage V2, a time constant tao of the duty cycle of a gradual ASC is calculated, tao=α*(V3-V2) / (V1-V3), where α is a calibration coefficient, and step 8 is executed;
[0086] Further, a gradual ASC is executed, and the duty cycle D of the ASC gradually increases from 0% to 100%, and the specific transfer function is G(s)=1 / (tao*s+1). Finally, the process ends.
[0087] In the above example, when the main relay of the battery is disconnected, the back electromotive force of the motor cannot be recovered through the battery. Therefore, the tube can be directly turned off at low speed, which will neither cause overvoltage nor overcurrent. At high speed, the tube is turned off for one cycle (125us) to reduce the current to 0 first, and then direct ASC is executed to avoid overvoltage while limiting the maximum current to within 1.5 times the peak current to minimize motor demagnetization.
[0088] In the above example, when the main relay of the battery is closed, the battery has a certain voltage regulation and energy recovery capability. If the motor speed is low and the back EMF is lower than the battery voltage, the controller can be turned off directly. When the motor speed is high, the motor rotor temperature is low and it is not easy to demagnetize. You can also turn off the controller for a cycle (125us) to reduce the current to 0 first, and then perform direct ASC. At this time, the maximum current is within 1.5 times the peak current and the motor rotor temperature is low, which can avoid motor demagnetization.
[0089] In the above example, when the main relay of the battery is closed, the motor back EMF is higher than the battery voltage, and the motor rotor temperature is high, the FGASC strategy is executed to limit the current to below the peak current to avoid motor demagnetization. At the same time, the duty cycle of ASC is set according to the motor back EMF V1, the current battery voltage V2, and the maximum operating voltage V3 according to the following transfer function:
[0090] G(s)=1 / (α*(V3-V2) / (V1-V3)*s+1).
[0091] This calculation formula can limit the voltage during ASC to within the maximum operating voltage of the system to avoid overvoltage damage to hardware.
[0092] Embodiment 2
[0093] See also Figure 3 , Figure 3 is a schematic diagram of the structure of a control device of a motor controller disclosed in an embodiment of the present application, such as Figure 3 As shown, the device of the embodiment of the present application includes the following functional modules:
[0094] The first judgment module 201 is used to judge whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed;
[0095] The second judgment module 202 is used to judge whether the motor rotor temperature is greater than a preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, a gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state.
[0096] The device of the embodiment of the present application can determine whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed, and further can determine whether the motor rotor temperature is greater than the preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state, and further while utilizing the three-phase active short circuit to avoid motor demagnetization, the voltage of the motor controller is limited to below the upper limit of the system operating voltage to avoid overvoltage damage to the motor controller or the battery.
[0097] It should be noted that for other detailed descriptions of the device in the embodiment of the present application, please refer to the relevant description of the embodiment of the present application, and the embodiment of the present application will not go into details.
[0098] Embodiment 3
[0099] See also Figure 4 , Figure 4 is a schematic diagram of the structure of an electronic device disclosed in an embodiment of the present application, such as Figure 4 As shown, the electronic device of the embodiment of the present application includes:
[0100] Processor 301; and
[0101] The memory 302 is configured to store machine-readable instructions, and when the instructions are executed by the processor 301, the control method of the motor controller as described in any of the aforementioned embodiments is performed.
[0102] The electronic device of the embodiment of the present application can determine whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed by executing the control method of the motor controller, and further determine whether the motor rotor temperature is greater than a preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state, thereby avoiding overvoltage damage to the motor controller or the battery by limiting the voltage of the motor controller to below the upper limit of the system operating voltage while utilizing the three-phase active short circuit to avoid motor demagnetization.
[0103] Embodiment 4
[0104] An embodiment of the present application provides a storage medium, wherein the storage medium stores a computer program, and the computer program is executed by a processor as a control method for a motor controller as described in any of the aforementioned implementations.
[0105] The storage medium of the embodiment of the present application can determine whether the motor back electromotive force is greater than the battery voltage when the main relay of the motor is closed by executing the control method of the motor controller, and further determine whether the motor rotor temperature is greater than a preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state, thereby avoiding overvoltage damage to the motor controller or the battery by limiting the voltage of the motor controller to below the upper limit of the system operating voltage while utilizing the three-phase active short circuit to avoid motor demagnetization.
[0106] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.
[0107] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
[0108] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.
[0109] It should be noted that if the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.
[0110] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.
[0111] The above are only embodiments of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.
Claims
1. A control method for a motor controller, characterized in that: The method comprises: When the main relay of the motor is closed, determine whether the motor back EMF is greater than the battery voltage; When the motor back electromotive force is greater than the battery voltage, it is determined whether the motor rotor temperature is greater than a preset temperature threshold; if the motor rotor temperature is greater than the preset temperature threshold, the gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state.
2. The method according to claim 1, characterized in that The method further comprises: When the main relay of the motor is disconnected, it is determined whether the motor speed is greater than the preset speed threshold. If the motor speed is greater than the preset speed threshold, the power modules of the motor controller are controlled to be completely shut down for 125us, and a direct three-phase active short-circuit strategy is executed after 125us to limit the maximum current of the motor controller.
3. The method according to claim 1, characterized in that The method further comprises: When the motor rotor temperature is lower than the preset temperature threshold, all power modules of the motor controller are controlled to be turned off for 125us, and a direct three-phase active short-circuit strategy is executed after 125us to limit the maximum current of the motor controller.
4. The method according to claim 1, characterized in that The step of calculating the gradual duty cycle of the three-phase active short-circuit state based on the upper limit of the system operating voltage includes: Calculating a time constant of the gradually changing duty cycle based on the motor back EMF and the battery voltage; The gradually changing duty cycle is calculated based on a time constant of the gradually changing duty cycle and an upper limit of the system operating voltage, wherein: G(s)=1 / (tao*s+1); tao=α*(V3-V2) / (V1-V3); Among them, tao represents the time constant of the gradual duty cycle, G(s) represents the gradual duty cycle, s represents time, α is the calibration coefficient, V1 represents the motor back electromotive force, V2 represents the battery voltage, and V3 represents the upper limit of the system operating voltage, which is determined based on the design parameters of the battery and the parameters of the motor controller.
5. The method according to claim 1, characterized in that The method further comprises: The motor back EMF is calculated based on the motor flux and the motor speed.
6. The method according to claim 2, characterized in that The method further comprises: When the main relay of the motor is disconnected and the motor speed is less than the preset speed threshold, all power modules controlling the motor controller are turned off.
7. The method according to claim 2, characterized in that The method further comprises: When the main relay of the motor is closed and the back electromotive force of the motor is less than the battery voltage, all power modules controlling the motor controller are turned off.
8. A control device for a motor controller, characterized in that: The device comprises: A first judgment module is used to judge whether the back electromotive force of the motor is greater than the battery voltage when the main relay of the motor is closed; The second judgment module is used to judge whether the motor rotor temperature is greater than a preset temperature threshold when the motor back electromotive force is greater than the battery voltage. If the motor rotor temperature is greater than the preset temperature threshold, a gradual duty cycle of the three-phase active short-circuit state is calculated based on the upper limit of the system operating voltage, and a flexible gradual three-phase active short-circuit strategy is executed based on the gradual duty cycle of the three-phase active short-circuit state, wherein the gradual duty cycle of the three-phase active short-circuit state is used to limit the voltage of the motor controller to below the upper limit of the system operating voltage in the three-phase active short-circuit state.
9. An electronic device, characterized in that: include: processor; as well as A memory configured to store machine-readable instructions, which, when executed by the processor, execute the control method of the motor controller as described in any one of claims 1-7.
10. A storage medium, characterized in that: The storage medium stores a computer program, and the computer program is executed by a processor to implement the control method of the motor controller as described in any one of claims 1 to 7.