Torque detection method and device of permanent magnet synchronous motor, vehicle, medium and product

Abstract

The invention discloses a torque detection method and device of a permanent magnet synchronous motor, a vehicle, a medium and a product. The method comprises the following steps: acquiring the rotating speed of the permanent magnet synchronous motor and current data corresponding to the permanent magnet synchronous motor; determining a current torque corresponding to the permanent magnet synchronous motor according to a first association relationship between the current data and the motor torque; determining a power torque corresponding to the permanent magnet synchronous motor according to a second incidence relation corresponding to the rotating speed of the permanent magnet synchronous motor; and detecting whether the output torque of the permanent magnet synchronous motor is abnormal according to the power torque and the current torque. According to the scheme provided by the embodiment of the invention, the torque of the motor can be accurately detected, so that damage to the vehicle caused by unexpected torque and unreasonable torque is reduced, and the safety of the vehicle is improved.

Description

Technical Field

[0001] The present application belongs to the field of motor technology, and in particular, relates to a torque detection method, device, vehicle, medium and product of a permanent magnet synchronous motor. Background Art

[0002] With the popularity of electric vehicles, the safety of electric vehicles has also received widespread attention, among which the torque safety of electric vehicles is one of the key aspects. How to monitor the torque of electric vehicles to reduce the risk of unexpected or unreasonable torque generated by the motor is of great significance to improving the safety of electric vehicles. Summary of the invention

[0003] The embodiments of the present application provide a torque detection method, device, vehicle, medium and product for a permanent magnet synchronous motor, which can detect the unexpected torque and unreasonable torque of the motor, improve the accuracy of vehicle torque detection, reduce the damage to the vehicle caused by unexpected torque and unreasonable torque, and improve the safety of the vehicle.

[0004] In a first aspect, an embodiment of the present application provides a torque detection method for a permanent magnet synchronous motor, the method comprising: obtaining the rotational speed of the permanent magnet synchronous motor and current data corresponding to the permanent magnet synchronous motor; determining the current torque corresponding to the permanent magnet synchronous motor based on a first correlation relationship between the current data and the motor torque; determining the power torque corresponding to the permanent magnet synchronous motor based on a second correlation relationship corresponding to the rotational speed of the permanent magnet synchronous motor; and detecting whether there is any abnormality in the output torque of the permanent magnet synchronous motor based on the power torque and the current torque.

[0005] In the second aspect, an embodiment of the present application provides a torque detection device for a permanent magnet synchronous motor, which includes: a data acquisition module, used to obtain the rotational speed of the permanent magnet synchronous motor, and current data corresponding to the permanent magnet synchronous motor; a current torque determination module, used to determine the current torque corresponding to the permanent magnet synchronous motor based on a first correlation relationship between the current data and the motor torque; a power torque determination module, used to determine the power torque corresponding to the permanent magnet synchronous motor based on a second correlation relationship corresponding to the rotational speed of the permanent magnet synchronous motor; a torque detection module, used to detect whether there is any abnormality in the output torque of the permanent magnet synchronous motor based on the power torque and the current torque.

[0006] In a third aspect, an embodiment of the present application provides a vehicle, which includes an electronic device, the electronic device including: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the torque detection method of the permanent magnet synchronous motor as described in the first aspect is implemented.

[0007] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, the torque detection method for a permanent magnet synchronous motor as described in the first aspect is implemented.

[0008] In a fifth aspect, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the torque detection method for a permanent magnet synchronous motor as described in the first aspect.

[0009] It can be seen from the above content that in the embodiment of the present application, the rationality of the output torque of the permanent magnet synchronous motor is judged according to the current torque and the power torque, the accuracy of the judgment is improved, and the safety of the vehicle is improved. In the embodiment of the present application, the current torque is calculated by the real-time current data of the permanent magnet synchronous motor, and the current torque can reflect the real-time operation state of the permanent magnet synchronous motor. By comparing the current torque with the target torque issued by the vehicle controller, it is possible to monitor whether the output torque of the permanent magnet synchronous motor is an unexpected torque, and then when the unexpected torque is monitored, control measures are taken in time to improve the safety of the vehicle. Moreover, in the embodiment of the present application, the power torque of the permanent magnet synchronous motor is determined by selecting a suitable correlation relationship according to the speed of the permanent magnet synchronous motor, the accuracy of the power torque detection is improved, and then the output torque of the permanent magnet synchronous motor is detected by the power torque and the current torque. Whether it is reasonable, reduce the damage caused to the vehicle by unreasonable torque output, and improve the safety of the vehicle.

[0010] It can be seen that the solution provided in the embodiment of the present application can detect the unexpected torque and unreasonable torque of the motor, improve the accuracy of vehicle torque detection, reduce the damage caused to the vehicle by unexpected torque and unreasonable torque, and improve the safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0012] Figure 1 It is a flow chart of a method for detecting torque of a permanent magnet synchronous motor provided by an embodiment of the present application;

[0013] Figure 2 It is a flowchart of a method for determining a second association relationship provided by an embodiment of the present application;

[0014] Figure 3 It is a flow chart of a method for detecting torque of a permanent magnet synchronous motor provided by an embodiment of the present application;

[0015] Figure 4 is a structural schematic diagram of a torque detection device for a permanent magnet synchronous motor provided by another embodiment of the present application;

[0016] Figure 5 It is a schematic diagram of the structure of a vehicle provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0017] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0018] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0019] For ease of understanding, before explaining the solution provided in the present application, the background of the solution provided in the present application is first explained.

[0020] Permanent magnet synchronous motor is a synchronous motor that uses permanent magnets to generate magnetic fields. Its rotor and speed are consistent with the current frequency of the stator winding. Permanent magnet synchronous motor has the advantages of high efficiency, good dynamic response performance, low noise, etc., and has been widely used in electric vehicles, robots and other fields that require high efficiency, high dynamic performance and low noise.

[0021] If the torque output by the permanent magnet synchronous motor is significantly different from the expected torque or is unreasonable, it will cause damage to the vehicle. In order to reduce the damage to the vehicle caused by the unexpected torque and / or unreasonable torque of the permanent magnet synchronous motor, the output torque of the permanent magnet synchronous motor needs to be detected in practical applications.

[0022] Based on this, the embodiments of the present application provide a method, device, vehicle, medium and product for detecting torque of a permanent magnet synchronous motor.

[0023] In the method provided in the embodiment of the present application, the current torque determined by the current of the permanent magnet synchronous motor and the power torque determined by the power in different speed ranges are calculated, and the rationality of the output torque of the permanent magnet synchronous motor is judged by the current torque and the power torque, so that when it is detected that the output torque of the permanent magnet synchronous motor is an unexpected torque or an unreasonable torque, timely measures can be taken to reduce the damage to the vehicle caused by the unexpected torque and unreasonable torque, thereby improving the safety of the vehicle.

[0024] The following first introduces the torque detection method of the permanent magnet synchronous motor provided in the embodiment of the present application.

[0025] It should be noted that the motor controller in the vehicle can be used as the execution subject of the method provided in the embodiment of the present application, wherein the motor controller can be connected to the vehicle controller to receive the control instructions issued by the vehicle controller and the relevant data for controlling the operation of the motor, and can also feedback the operation status of the motor to the vehicle controller. The motor controller is connected to the motor and is used to control the operation of the motor according to the control instructions issued by the vehicle controller.

[0026] In addition, it should be noted that the method provided in the embodiment of the present application can be used to implement the control of all permanent magnet synchronous motors.

[0027] Figure 1 FIG. 1 is a flow chart showing a method for detecting torque of a permanent magnet synchronous motor provided by an embodiment of the present application. Figure 1 As shown, the method includes the following steps S101 to S104:

[0028] Step S101, obtaining the rotation speed of the permanent magnet synchronous motor and the current data corresponding to the permanent magnet synchronous motor.

[0029] In step S101, a speed sensor is provided in the vehicle, which can detect the speed of the permanent magnet synchronous motor in real time. The motor controller is connected to the speed sensor to obtain the speed detected by the speed sensor.

[0030] In step S101 , the current data includes a direct-axis current and a quadrature-axis current, wherein the direct-axis current is the current value on the direct axis in the orthogonal coordinate system corresponding to the permanent magnet synchronous motor; and the quadrature-axis current is the current value on the quadrature axis in the orthogonal coordinate system.

[0031] It should be noted that, in practical applications, the direct-axis current and the quadrature-axis current of the permanent magnet synchronous motor can be obtained by performing coordinate transformation on the phase current of the permanent magnet synchronous motor.

[0032] As an example, in a three-phase AC motor, the three-phase currents, i.e., the currents of the U phase, the V phase, and the W phase, can be detected by a three-phase current sensor respectively. Then, the following formula (1) can be used to implement the following:

[0033]

[0034] In formula (1), i d is the direct axis current, i q is the quadrature axis current, i a is the U phase current, i b is the V phase current, i c is the W phase current, and θ is the motor rotor position.

[0035] Step S102: determining the current torque corresponding to the permanent magnet synchronous motor according to the first correlation relationship between the current data and the motor torque.

[0036] In step S102, the current torque is a torque determined by the current data of the permanent magnet synchronous motor. In the embodiment of the present application, a calibration method can be used to determine the first correlation relationship between the current data and the motor torque.

[0037] It should be noted that the permanent magnet synchronous motor does not have a torque sensor, and the torque described in the embodiments of the present application is calculated by using torque-related expressions and variables in the expressions. In the embodiments of the present application, the prerequisite for torque detection is that the permanent magnet synchronous motor has been calibrated and the torque model of the permanent magnet synchronous motor is accurate.

[0038] As an example, the current torque model used in calibration can be expressed by formula (2):

[0039] T p1 =3P p [ψ f i q +(L d -L q )i d i q ]-T q_loss (2)

[0040] In formula (2), T p1 is the current torque, P p is the number of motor pole pairs, ψ f is the rotor flux, L d is the direct-axis inductance, L q is the quadrature-axis inductance, i q is the quadrature axis current, i d is the direct axis current, T q_loss It is the friction torque generated by the rotation of the permanent magnet synchronous motor.

[0041] The torque model corresponding to the permanent magnet synchronous motor is calibrated to determine the accurate number of motor pole pairs, rotor flux and friction torque, so that after the direct-axis current and quadrature-axis current corresponding to the target torque are input into the torque model, the difference between the current torque output by the torque model and the target torque is within an acceptable fluctuation range.

[0042] Step S103: determining the power torque corresponding to the permanent magnet synchronous motor according to a second correlation relationship corresponding to the rotation speed of the permanent magnet synchronous motor.

[0043] In step S103, for different speed ranges, the second correlation relationship between torque and motor power is different. For example, when the speed corresponding to the permanent magnet synchronous motor is an extremely low speed, the second correlation relationship corresponding to the power-torque is determined by the phase current amplitude; when the speed corresponding to the permanent magnet synchronous motor is in a normal speed range, the second correlation relationship corresponding to the power-torque is determined by the phase current, bus voltage and motor power loss of the permanent magnet synchronous motor.

[0044] It should be noted that the second correlation relationship is selected according to the speed range corresponding to the speed of the permanent magnet synchronous motor, so that the calculated power torque is more consistent with the actual scenario, the accuracy of the power torque calculation is improved, and the detection accuracy of the output torque of the permanent magnet synchronous motor is further improved.

[0045] Step S104: detecting whether the output torque of the permanent magnet synchronous motor is abnormal based on the power torque and the current torque.

[0046] In step S104, the output torque of the permanent magnet synchronous motor is the same as the torque value of the current torque, wherein the output torque abnormality of the permanent magnet synchronous motor may include two aspects, namely, whether the output torque meets expectations (i.e., whether the difference between the output torque and the target torque is within an acceptable range) and whether the output torque is reasonable (i.e., whether the difference between the output torque and the power torque is within an acceptable range).

[0047] In the embodiment of the present application, the motor controller can monitor whether the output torque of the permanent magnet synchronous motor meets expectations by comparing the current torque with the target torque issued by the vehicle controller; the motor controller determines whether the output torque of the permanent magnet synchronous motor is reasonable by comparing the current torque and the power torque. That is, in the embodiment of the present application, by comprehensively analyzing the power torque and the current torque, the detection accuracy of the output torque of the permanent magnet synchronous motor can be improved, and then when the output torque of the permanent magnet synchronous motor is detected to be abnormal, relevant measures can be taken in time to reduce the damage to the vehicle caused by the abnormal output torque and improve the safety of the vehicle.

[0048] Based on the scheme defined by the above steps S101 to S104, it can be known that in the embodiment of the present application, the output torque of the permanent magnet synchronous motor is judged for rationality according to the current torque and the power torque, the accuracy of the judgment is improved, and the safety of the vehicle is improved. In the embodiment of the present application, the current torque is calculated by the real-time current data of the permanent magnet synchronous motor, and the current torque can reflect the real-time operation state of the permanent magnet synchronous motor. By comparing the current torque with the target torque issued by the vehicle controller, it is possible to monitor whether the output torque of the permanent magnet synchronous motor is an unexpected torque, and then when the unexpected torque is monitored, control measures are taken in time to improve the safety of the vehicle. Moreover, in the embodiment of the present application, the power torque of the permanent magnet synchronous motor is determined by selecting a suitable correlation relationship according to the speed of the permanent magnet synchronous motor, the accuracy of the power torque detection is improved, and then the output torque of the permanent magnet synchronous motor is detected by the power torque and the current torque. Whether it is reasonable, reduce the damage caused to the vehicle by unreasonable torque output, and improve the safety of the vehicle.

[0049] It can be seen that the solution provided in the embodiment of the present application can detect the unexpected torque and unreasonable torque of the motor, improve the accuracy of vehicle torque detection, reduce the damage caused to the vehicle by unexpected torque and unreasonable torque, and improve the safety of the vehicle.

[0050] The following is an introduction to the implementation process of the method provided in the embodiment of the present application.

[0051] In one embodiment, after obtaining the rotation speed and current data of the permanent magnet synchronous motor, the motor controller may determine the current torque corresponding to the permanent magnet synchronous motor according to a first correlation relationship between the current data and the motor torque.

[0052] Specifically, the motor controller first obtains the inductance data, rotor flux, motor pole pair number and friction torque generated by the rotation of the permanent magnet synchronous motor; then, according to the inductance data, rotor flux and motor pole pair number, the torque coefficient corresponding to the permanent magnet synchronous motor is determined; then, according to the current data, the torque coefficient and the first correlation relationship, the initial current torque corresponding to the permanent magnet synchronous motor is determined; and then the difference between the initial current torque and the friction torque is calculated to obtain the current torque.

[0053] In the above embodiment, the inductance data includes the direct-axis inductance and the quadrature-axis inductance of the permanent magnet synchronous motor. The above first correlation relationship can be shown as formula (2), wherein the inductance data, rotor flux, motor pole pair number and friction torque in formula (2) can be determined by calibrating the torque model.

[0054] The torque coefficient in the above embodiment includes a first torque coefficient and a second torque coefficient. The motor controller can determine the first torque coefficient according to the rotor flux and the number of motor pole pairs; and determine the second torque coefficient according to the number of motor pole pairs, direct-axis inductance, and quadrature-axis inductance.

[0055] As an example, the first torque coefficient may be the product of the rotor flux and the number of motor pole pairs, and the second torque coefficient may be the product of the difference between the direct-axis inductance and the quadrature-axis inductance and the rotor flux. In formula (2), the first torque coefficient may be P p ψ f , the second torque coefficient can be P p (L d -L q ).

[0056] Furthermore, the current torque can be the torque difference between the initial current torque and the friction torque, wherein the motor controller can calculate the product of the first torque coefficient and the direct-axis current to obtain the first current torque; and calculate the product of the second torque coefficient and the direct-axis current and the quadrature-axis current to obtain the second current torque; then, based on the first correlation relationship, the first current torque and the second current torque, the initial current torque can be determined.

[0057] As an example, formula (2) can be expressed as formula (3):

[0058] T p1 =T p0 -T qloss =3P p [ψ f i q +(L d -L q )i d i q ]-T q_loss (3)

[0059] In formula (3), T p0 is the initial current torque, T p0 =3P p [ψ f i q +(L d -L q )i d i q ]; The first current torque is 3P p ψ f i q , the second current torque is 3P p (L d -L q )i d i q .

[0060] Regarding the power torque, as shown in step S103, before determining the power torque, a second correlation relationship corresponding to the motor speed needs to be determined.

[0061] In one embodiment, Figure 2 The process of determining the second association relationship is shown, such as Figure 2 As shown, the process includes the following steps S201 to S205:

[0062] Step S201, detecting whether the speed of the permanent magnet synchronous motor is within a preset speed range, if the speed is within the preset speed range, executing step S202, otherwise executing step S203;

[0063] Step S202, determining a second correlation relationship according to current data, voltage data and motor power loss of the permanent magnet synchronous motor;

[0064] Step S203, detecting whether the rotation speed is less than the lower limit of the preset rotation speed range, if so, executing step S204, otherwise, executing step S205;

[0065] Step S204, determining a second correlation relationship according to the phase current amplitude corresponding to the permanent magnet synchronous motor;

[0066] Step S205, determining whether the permanent magnet synchronous motor has an abnormality.

[0067] In the above steps S201 to S205, the preset speed range is the speed range for normal operation of the permanent magnet synchronous motor. When the speed of the permanent magnet synchronous motor is less than the lower limit of the preset speed range, it can be determined that the speed of the permanent magnet synchronous motor is an extremely low speed.

[0068] For step S202, that is, when the speed of the permanent magnet synchronous motor is within the preset speed range, the motor controller determines the second association relationship according to the current data, voltage data and motor power loss of the permanent magnet synchronous motor.

[0069] Specifically, the motor controller first calculates the difference between the motor power and the motor power loss to obtain the actual power of the permanent magnet synchronous motor; then, a correlation relationship between the actual power, the speed, and the power torque of the permanent magnet synchronous motor is constructed to obtain the second correlation relationship.

[0070] As an example, the second association relationship mentioned above can be expressed by formula (4):

[0071]

[0072] In formula (4), T p2 is the power torque, P0 is the motor power, P lossis the motor power loss, and n is the speed of the permanent magnet synchronous motor.

[0073] The motor power can be expressed by formula (5):

[0074] P0=u a ×i a +u b ×i b +u b ×i c (5)

[0075] In formula (5), i a 、i b 、i c is the measured value of the three-phase current of the permanent magnet synchronous motor, u a 、u b 、u b It is the product of the three-phase voltage of the permanent magnet synchronous motor detected in real time by the bus voltage sensor and the corresponding phase voltage duty cycle.

[0076] In formula (4), the motor power loss may include but is not limited to iron loss and copper loss, wherein iron loss is the energy loss caused by the hysteresis and eddy current effect of the core material during the operation of the permanent magnet synchronous motor; copper loss is the sum of the energy consumed by the primary and secondary currents of the permanent magnet synchronous motor flowing through the coil resistance. In the embodiment of the present application, the motor power loss can be determined by calibration.

[0077] In one embodiment, the motor controller first obtains the bus current and bus voltage of the permanent magnet synchronous motor, and then determines the total electric power corresponding to the permanent magnet synchronous motor based on the bus current and bus voltage; then queries the torque corresponding to the speed from a preset speed-torque relationship diagram, and determines the mechanical power of the permanent magnet synchronous motor based on the torque corresponding to the speed and the speed; finally, the difference between the total electric power and the mechanical power is calculated to obtain the motor power loss.

[0078] In the above embodiment, the total electric power of the permanent magnet synchronous motor can be the product of the bus current and the bus voltage, which can be expressed by formula (6):

[0079] P1=U×I (6)

[0080] In formula (6), P1 is the total electric power of the permanent magnet synchronous motor, U is the bus voltage, and I is the bus current.

[0081] In the above embodiment, the preset speed-torque relationship diagram includes the speed and torque at different operating points, that is, in the embodiment of the present application, the speed-torque relationship diagram is a MAP diagram with the speed as the horizontal coordinate and the torque as the vertical coordinate. After determining the speed corresponding to the permanent magnet synchronous motor, the torque corresponding to the speed can be determined by querying the MAP diagram, and then the mechanical power corresponding to the permanent magnet synchronous motor can be obtained by formula (7):

[0082]

[0083] In formula (7), P2 is the mechanical power of the permanent magnet synchronous motor, T p is the torque determined by querying the speed-torque relationship diagram, and n is the speed.

[0084] It should be noted that, in the process of constructing the speed-torque relationship diagram, for operating points that cannot be measured, interpolation calculation can be used to determine them, so as to improve the accuracy of the speed-torque relationship diagram.

[0085] After obtaining the total electrical power and mechanical power of the permanent magnet synchronous motor, the difference between the two can be calculated to obtain the motor power loss, as shown in formula (8):

[0086] P loss =P1-P2 (8)

[0087] It should be noted that when the motor speed of the permanent magnet synchronous motor is very low, the speed as a divisor in formula (4) may cause errors in the calculation results. If the motor power loss P is added loss Using interpolation as the output result may cause power torque calculation errors when the permanent magnet synchronous motor has an extremely low speed.

[0088] To solve this problem, in an embodiment of the present application, when the speed of the permanent magnet synchronous motor is less than the lower limit of the preset speed range, the motor controller determines the second association relationship according to the phase current amplitude corresponding to the permanent magnet synchronous motor.

[0089] In one embodiment, the motor controller obtains a preset power coefficient, constructs a correlation relationship among the power coefficient, the phase current amplitude, and the power torque, and thus obtains the second correlation relationship.

[0090] As an example, when the speed of the permanent magnet synchronous motor is less than the lower limit of the preset speed range, the second association relationship can be expressed by formula (9):

[0091] T p2 =fac×I amp (9)

[0092] In formula (9), fac is the preset power factor, Iamp is the phase current amplitude.

[0093] It should be noted that in the low-speed or base speed zone, since the MTPA (Maximum Torque PerAmpere) optimal current ratio scheme is adopted to control the permanent magnet synchronous motor, the torque and current have a one-to-one correspondence and are independent of the speed. In the embodiment of the present application, the selection of the power coefficient fac is also based on the actual corresponding coefficient.

[0094] In addition, it should be noted that formula (9) is only applicable to the extremely low speed scenario of the permanent magnet synchronous motor. In this scenario, the calculation method of the current torque is the same as formula (3), which will not be repeated here.

[0095] Furthermore, after obtaining the current torque and the power torque, the motor controller can detect whether there is an abnormality in the output torque of the permanent magnet synchronous motor according to the power torque and the current torque.

[0096] In one embodiment, the torque detection method of the permanent magnet synchronous motor can be as follows: Figure 3 As shown, the process includes the following steps:

[0097] Step S301, obtaining the target torque issued by the vehicle controller.

[0098] In step S301, the motor controller may communicate with the vehicle controller, and the motor controller may obtain the target torque issued by the vehicle controller through the communication connection.

[0099] Step S302, calculating the difference between the target torque and the current torque to obtain a first torque difference.

[0100] In step S302, the first torque difference is used to characterize whether the output torque of the permanent magnet synchronous motor meets the torque requirement. If the first torque difference is relatively large, it indicates that the difference between the output torque of the permanent magnet synchronous motor and the target torque issued by the permanent magnet synchronous motor is large, and the output torque of the permanent magnet synchronous motor does not meet the expected torque requirement.

[0101] Step S303, calculating the difference between the current torque and the power torque to obtain a second torque difference.

[0102] In step S303, the second torque difference is used to characterize whether the output torque of the permanent magnet synchronous motor meets the preset torque setting requirement, wherein, under normal operating conditions, the difference between the current torque and the power torque is small; if the difference between the current torque and the power torque is large, it may be that the target torque setting is unreasonable, or the torque model does not match the permanent magnet synchronous motor, or other reasons may cause it, that is, the permanent magnet synchronous motor outputs unreasonable torque.

[0103] Step S304, detecting whether the first torque difference is within the first torque range, and whether the second torque difference is within the second torque range, wherein if the first torque difference is within the first torque range, and the second torque difference is within the second torque range, executing step S305, otherwise executing step S306.

[0104] Step S305 , when the first torque difference is within the first torque range and the second torque difference is within the second torque range, determining that the output torque of the permanent magnet synchronous motor is within a normal range.

[0105] Step S306: When the first torque difference is outside the first torque range and / or the second torque difference is outside the second torque range, it is determined that the output torque of the permanent magnet synchronous motor is abnormal.

[0106] In step S306, when the first torque difference is outside the first torque range, that is, when the difference between the target torque issued by the vehicle controller and the current torque exceeds a preset first threshold, the motor controller determines that the permanent magnet synchronous motor has an unexpected torque. At this time, the motor controller takes relevant control measures to control the IGBT (Insulate-Gate Bipolar Transistor) corresponding to the permanent magnet synchronous motor to turn off, and the permanent magnet synchronous motor stops running.

[0107] When the second torque difference is outside the second torque range, that is, when the difference between the current torque and the power torque exceeds a preset second threshold, the motor controller determines that the torque output by the permanent magnet synchronous motor is unreasonable. At this time, the motor controller takes relevant control measures to control the IGBT corresponding to the permanent magnet synchronous motor to turn off, and the permanent magnet synchronous motor stops running.

[0108] This completes the introduction of the method provided in the embodiment of the present application.

[0109] As can be seen from the above introduction, in the solution provided in the embodiment of the present application, by calculating the current torque and the power torque in different speed ranges, the torque is judged and monitored for rationality, thereby improving the safety of the vehicle and avoiding damage caused by the vehicle generating unexpected torque or unreasonable output torque. In addition, in the embodiment of the present application, the speed of the permanent magnet synchronous motor is also judged, and when the speed is extremely low, a replacement power torque calculation method is set to improve the accuracy of the power torque calculation, and then the torque rationality check is completed according to the current torque calculation method and the replaced power torque calculation method, thereby improving the accuracy of the torque detection of the permanent magnet synchronous motor.

[0110] The present application also provides a torque detection device for a permanent magnet synchronous motor. Figure 4As shown, the device 400 includes: a data acquisition module 401 , a current torque determination module 402 , a power torque determination module 403 and a torque detection module 404 .

[0111] The data acquisition module 401 is used to acquire the rotation speed of the permanent magnet synchronous motor and the current data corresponding to the permanent magnet synchronous motor;

[0112] A current torque determination module 402 is used to determine the current torque corresponding to the permanent magnet synchronous motor according to a first correlation relationship between the current data and the motor torque;

[0113] A power torque determination module 403, configured to determine the power torque corresponding to the permanent magnet synchronous motor according to a second correlation relationship corresponding to the rotation speed of the permanent magnet synchronous motor;

[0114] The torque detection module 404 is used to detect whether the output torque of the permanent magnet synchronous motor is abnormal according to the power torque and the current torque.

[0115] In one embodiment, the current torque determination module is specifically used to obtain the inductance data, rotor flux, motor pole pair number and friction torque generated by the rotation of the permanent magnet synchronous motor; determine the torque coefficient corresponding to the permanent magnet synchronous motor according to the inductance data, rotor flux and motor pole pair number; determine the initial current torque corresponding to the permanent magnet synchronous motor according to the current data, torque coefficient and the first association relationship; calculate the difference between the initial current torque and the friction torque to obtain the current torque.

[0116] In one embodiment, the torque detection device of the permanent magnet synchronous motor further includes: a first determination module and a second determination module. The first determination module is used to determine the second association relationship according to the current data, voltage data and motor power loss of the permanent magnet synchronous motor before determining the power torque corresponding to the permanent magnet synchronous motor according to the second association relationship corresponding to the speed of the permanent magnet synchronous motor when the speed is within a preset speed range; the second determination module is used to determine the second association relationship according to the phase current amplitude corresponding to the permanent magnet synchronous motor when the speed is less than the lower limit of the preset speed range.

[0117] In one embodiment, the first determination module is specifically used to calculate the difference between the motor power and the motor power loss to obtain the actual power of the permanent magnet synchronous motor; construct a correlation relationship between the actual power, the speed, and the power torque of the permanent magnet synchronous motor to obtain a second correlation relationship.

[0118] In one embodiment, the torque detection device of the permanent magnet synchronous motor also includes: a loss determination module, which is used to obtain the bus current and bus voltage of the permanent magnet synchronous motor before determining the second correlation relationship based on the current data, voltage data and motor power loss of the permanent magnet synchronous motor; determine the total electric power corresponding to the permanent magnet synchronous motor based on the bus current and bus voltage; query the torque corresponding to the speed from a preset speed-torque relationship diagram; determine the mechanical power of the permanent magnet synchronous motor based on the torque corresponding to the speed and the speed; calculate the difference between the total electric power and the mechanical power to obtain the motor power loss.

[0119] In one embodiment, the second determination module is specifically used to obtain a preset power coefficient; construct a correlation relationship between the power coefficient, the phase current amplitude and the power torque to obtain a second correlation relationship.

[0120] In one embodiment, the torque detection module is specifically used to obtain the target torque issued by the vehicle controller; calculate the difference between the target torque and the current torque to obtain a first torque difference, wherein the first torque difference is used to characterize whether the output torque of the permanent magnet synchronous motor meets the torque requirement; calculate the difference between the current torque and the power torque to obtain a second torque difference, wherein the second torque difference is used to characterize whether the output torque of the permanent magnet synchronous motor meets the preset torque setting requirement; when the first torque difference is within the first torque range and the second torque difference is within the second torque range, it is determined that the output torque of the permanent magnet synchronous motor is within the normal range; when the first torque difference is outside the first torque range and / or the second torque difference is outside the second torque range, it is determined that the output torque of the permanent magnet synchronous motor is abnormal.

[0121] The torque detection device for a permanent magnet synchronous motor provided in the embodiment of the present application can implement each process implemented in the aforementioned method embodiment, and will not be described again here to avoid repetition.

[0122] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0123] Figure 5 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application is shown.

[0124] The electronic device may include a processor 501 and a memory 502 storing computer program instructions.

[0125] Specifically, the processor 501 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0126] The memory 502 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 502 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 502 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 502 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 502 is a non-volatile solid-state memory.

[0127] The memory may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical or other physical / tangible memory storage devices. Thus, typically, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0128] The processor 501 reads and executes computer program instructions stored in the memory 502 to implement any one of the torque detection methods for the permanent magnet synchronous motor in the above embodiments.

[0129] In one example, the electronic device may further include a communication interface 503 and a bus 510. Figure 5 As shown, the processor 501, the memory 502, and the communication interface 503 are connected via a bus 510 and communicate with each other.

[0130] The communication interface 503 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0131] Bus 510 includes hardware, software or both, and the parts of electronic equipment are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 510 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the application considers any suitable bus or interconnection.

[0132] In addition, in combination with the torque detection method of the permanent magnet synchronous motor in the above embodiment, the embodiment of the present application can provide a computer-readable storage medium for implementation. The computer-readable storage medium stores computer program instructions; when the computer program instructions are executed by the processor, any of the torque detection methods of the permanent magnet synchronous motor in the above embodiment is implemented.

[0133] In addition, in combination with the torque detection method of the permanent magnet synchronous motor in the above embodiment, the embodiment of the present application can provide a computer program product for implementation. When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device executes and implements any of the torque detection methods of the permanent magnet synchronous motor in the above embodiment.

[0134] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0135] The functional modules shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. Programs or code segments can be stored in machine-readable media, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable media" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0136] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0137] The above describes various aspects of the present disclosure with reference to the flowcharts and / or block diagrams of the torque detection method, device, vehicle, medium and product of the permanent magnet synchronous motor according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of boxes in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the functions / actions specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0138] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A method for detecting torque of a permanent magnet synchronous motor, characterized in that: include: Obtaining the rotation speed of the permanent magnet synchronous motor and the current data corresponding to the permanent magnet synchronous motor; Determining the current torque corresponding to the permanent magnet synchronous motor according to a first correlation relationship between the current data and the motor torque; Determining a power torque corresponding to the permanent magnet synchronous motor according to a second correlation relationship corresponding to a rotation speed of the permanent magnet synchronous motor; Whether the output torque of the permanent magnet synchronous motor is abnormal is detected according to the power torque and the current torque.

2. The method according to claim 1, characterized in that: The determining, according to the first correlation between the current data and the motor torque, the current torque corresponding to the permanent magnet synchronous motor comprises: Acquire the inductance data, rotor flux, number of motor pole pairs and friction torque generated by the rotation of the permanent magnet synchronous motor; Determining a torque coefficient corresponding to the permanent magnet synchronous motor according to the inductance data, the rotor flux and the number of motor pole pairs; Determining an initial current torque corresponding to the permanent magnet synchronous motor according to the current data, the torque coefficient and the first association relationship; The difference between the initial current torque and the friction torque is calculated to obtain the current torque.

3. The method according to claim 1, characterized in that Before determining the power torque corresponding to the permanent magnet synchronous motor according to the second association relationship corresponding to the rotation speed of the permanent magnet synchronous motor, the method further includes: When the speed is within a preset speed range, determining the second association relationship according to current data, voltage data and motor power loss of the permanent magnet synchronous motor; When the rotation speed is less than a lower limit of the preset rotation speed range, the second association relationship is determined according to a phase current amplitude corresponding to the permanent magnet synchronous motor.

4. The method according to claim 3, characterized in that The determining the second association relationship according to the current data, the voltage data and the motor power loss of the permanent magnet synchronous motor includes: Calculating the difference between the motor power and the motor power loss to obtain the actual power of the permanent magnet synchronous motor; A correlation relationship among the actual power, the rotational speed, and the power torque of the permanent magnet synchronous motor is constructed to obtain the second correlation relationship.

5. The method according to claim 4, characterized in that Before determining the second association relationship according to the current data, voltage data and motor power loss of the permanent magnet synchronous motor, the method further includes: Obtaining the bus current and bus voltage of the permanent magnet synchronous motor; Determine the total electric power corresponding to the permanent magnet synchronous motor according to the bus current and the bus voltage; Querying the torque corresponding to the speed from a preset speed-torque relationship diagram; determining the mechanical power of the permanent magnet synchronous motor according to the torque corresponding to the rotational speed and the rotational speed; The difference between the total electrical power and the mechanical power is calculated to obtain the motor power loss.

6. The method according to claim 3, characterized in that The determining the second association relationship according to the phase current amplitude corresponding to the permanent magnet synchronous motor includes: Get the preset power factor; A correlation relationship among the power coefficient, the phase current amplitude and the power torque is constructed to obtain the second correlation relationship.

7. The method according to any one of claims 1 to 6, characterized in that The detecting whether the output torque of the permanent magnet synchronous motor is abnormal according to the power torque and the current torque includes: Obtain the target torque issued by the vehicle controller; Calculating a difference between the target torque and the current torque to obtain a first torque difference, wherein the first torque difference is used to indicate whether the output torque of the permanent magnet synchronous motor meets the torque requirement; Calculating a difference between the current torque and the power torque to obtain a second torque difference, wherein the second torque difference is used to indicate whether the output torque of the permanent magnet synchronous motor meets a preset torque setting requirement; When the first torque difference is within a first torque range and the second torque difference is within a second torque range, determining that the output torque of the permanent magnet synchronous motor is within a normal range; When the first torque difference is outside the first torque range and / or the second torque difference is outside the second torque range, it is determined that an output torque of the permanent magnet synchronous motor is abnormal.

8. A torque detection device for a permanent magnet synchronous motor, characterized in that: include: A data acquisition module, used to acquire the rotation speed of the permanent magnet synchronous motor and the current data corresponding to the permanent magnet synchronous motor; A current torque determination module, used to determine the current torque corresponding to the permanent magnet synchronous motor according to a first correlation relationship between the current data and the motor torque; A power torque determination module, configured to determine the power torque corresponding to the permanent magnet synchronous motor according to a second correlation relationship corresponding to the rotation speed of the permanent magnet synchronous motor; The torque detection module is used to detect whether the output torque of the permanent magnet synchronous motor is abnormal according to the power torque and the current torque.

9. A vehicle, characterized in that: The vehicle includes an electronic device, the electronic device including: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the torque detection method of the permanent magnet synchronous motor as described in any one of claims 1-7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by the processor, the torque detection method for the permanent magnet synchronous motor according to any one of claims 1 to 7 is implemented.

11. A computer program product, characterized in that When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the torque detection method for a permanent magnet synchronous motor as described in any one of claims 1 to 7.

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