Permanent magnet synchronous motor current loop control method, device and equipment and storage medium

Abstract

The invention relates to a permanent magnet synchronous motor current loop control method which is executed by a vehicle and comprises the following steps: acquiring real-time current passing through a permanent magnet synchronous motor stator winding of the vehicle under a three-phase static coordinate system; converting the real-time current under the three-phase static coordinate system into a d-axis current and a q-axis current under a two-phase rotating coordinate system; generating a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the rotating speed of the motor and the current command; performing decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage; obtaining an overcurrent fault flag bit according to the d-axis current and the q-axis current; determining PWM switching frequency and current loop PI controller parameters based on the rotating speed of the motor; and controlling a permanent magnet synchronous motor current loop in the vehicle according to the d-axis voltage signal, the q-axis voltage signal, the overcurrent fault flag bit, the PWM switching frequency and the parameters of the current loop PI controller.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of vehicle motor drive technology, and in particular to a permanent magnet synchronous motor current loop control method, device, equipment and storage medium. Background Art

[0002] With the rapid development of new energy vehicles, the motors in new energy vehicles can provide effective assistance for the driving of new energy vehicles. The current loop of the motor control system can accurately control the magnitude and phase of the motor stator current, which directly affects the motor's torque output and dynamic response. Therefore, the control of the current loop is particularly important.

[0003] In the related technology, the motor control system can adopt vector control to realize the control of the current loop through coordinate transformation and magnetic field orientation. Specifically, the vehicle's motor control system can decompose the stator current of the AC motor into the magnetic field current component of the magnetic field orientation coordinate and the coordinate torque current component perpendicular to it, and then design the current loop PI controller based on the decoupled current component to generate corresponding voltage instructions to realize the control of the permanent magnet synchronous motor current loop.

[0004] However, in the vector control strategy shown in the above-mentioned related art, the parameter confirmation method of the current loop PI controller is relatively simple, the control efficiency of the permanent magnet synchronous motor current loop is low, and the control effect is poor. Summary of the invention

[0005] The embodiment of the present application provides a permanent magnet synchronous motor current loop control method, device, equipment and storage medium, which can improve the control efficiency of the permanent magnet synchronous motor current loop. The technical solution is as follows:

[0006] In one aspect, a method for controlling a current loop of a permanent magnet synchronous motor is provided, the method being executed by a vehicle, the method comprising:

[0007] Acquire the real-time current in a three-phase stationary coordinate system of the stator winding of the permanent magnet synchronous motor of the vehicle;

[0008] Converting the real-time current in the three-phase stationary coordinate system into a d-axis current and a q-axis current in a two-phase rotating coordinate system;

[0009] Generate a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the motor speed and the current command; the current command is used to indicate the expected d-axis voltage signal and the expected q-axis voltage signal;

[0010] Performing a decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage;

[0011] Acquire an overcurrent fault flag bit according to the d-axis current and the q-axis current;

[0012] Determine the PWM switching frequency and the current loop PI controller parameters based on the motor speed;

[0013] The permanent magnet synchronous motor current loop in the vehicle is controlled according to the d-axis command voltage, the q-axis command voltage, the overcurrent fault flag, the PWM switching frequency and the current loop PI controller parameters.

[0014] On the other hand, a permanent magnet synchronous motor current loop control device is provided, the device comprising:

[0015] A current acquisition module, used to acquire the real-time current in a three-phase stationary coordinate system of the stator winding of the permanent magnet synchronous motor of the vehicle;

[0016] A coordinate transformation module, used for converting the real-time current in a three-phase stationary coordinate system into a d-axis current and a q-axis current in a two-phase rotating coordinate system;

[0017] a voltage signal generating module, configured to generate a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the motor speed and a current command; the current command is used to indicate an expected d-axis voltage signal and an expected q-axis voltage signal;

[0018] a decoupling operation execution module, used for executing a decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage;

[0019] An overcurrent fault flag acquisition module, used to acquire an overcurrent fault flag according to the d-axis current and the q-axis current;

[0020] A parameter determination module, used to determine the PWM switching frequency and the current loop PI controller parameters based on the motor speed;

[0021] A current loop control module is used to control the permanent magnet synchronous motor current loop in the vehicle according to the d-axis command voltage, the q-axis command voltage, the overcurrent fault flag, the PWM switching frequency and the current loop PI controller parameters.

[0022] In some embodiments, the parameter determination module is used to determine the operating interval corresponding to the motor speed based on the motor speed; the operating interval is one of an acceleration interval, a rated operating interval, a constant power interval, a deceleration interval, a low-speed operating interval, and a high-speed operating interval;

[0023] Based on the operation range, the PWM switching frequency and the current loop PI controller parameters are determined.

[0024] In some embodiments, the parameter determination module is used to compare the motor speed with at least one preset speed interval;

[0025] When the motor speed satisfies a specified speed interval, obtaining the specified speed interval as an operating interval corresponding to the motor speed;

[0026] The determining of the PWM switching frequency and the current loop PI controller parameters based on the operating range includes:

[0027] According to the operating range, the corresponding relationship between the operating range and the PWM switching frequency and the current loop PI controller parameters is queried to obtain the PWM switching frequency and the current loop PI controller parameters corresponding to the operating range.

[0028] In some embodiments, the parameter determination module is used to determine a switching speed hysteresis value of the motor based on the operating interval; the switching speed hysteresis value is a buffer speed threshold when the motor switches between different speed intervals;

[0029] According to the absolute value of the motor speed, the switching speed hysteresis value and the switching speed value, the correspondence between the operating range and the PWM switching frequency and the current loop PI controller parameters is queried to determine the PWM switching frequency and the current loop PI controller parameters; the switching speed value is the speed critical value when the motor switches between different speed ranges.

[0030] In some embodiments, the parameter determination module is used to query and obtain the PWM switching frequency and the current loop PI controller parameter corresponding to the operating interval one level higher than the operating interval in the corresponding relationship between the operating interval and the PWM switching frequency and the current loop PI controller parameter when the sum of the switching speed hysteresis value and the switching speed value is less than the absolute value of the motor speed;

[0031] When the sum of the switching speed hysteresis value and the switching speed value is greater than the absolute value of the motor speed, the PWM switching frequency and the current loop PI controller parameters corresponding to the operating interval that is one level lower than the operating interval are queried to obtain the corresponding relationship between the operating interval and the PWM switching frequency and the current loop PI controller parameters.

[0032] In some embodiments, the coordinate transformation module is used to transform the current in the three-phase stationary coordinate system into the current in the two-phase stationary coordinate system through Clarke transformation;

[0033] The two-phase stationary coordinate system current is converted into d-axis and q-axis currents in a two-phase synchronous rotating coordinate system through the Park transformation.

[0034] On the other hand, a computer device is provided, which includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by the processor to implement the permanent magnet synchronous motor current loop control method as described above.

[0035] On the other hand, a computer-readable storage medium is provided, in which at least one instruction, at least one program, a code set or an instruction set is stored, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by a processor to implement the permanent magnet synchronous motor current loop control method as described above.

[0036] In another aspect, a computer program product is provided, the computer program product comprising a computer program, the computer program being stored in a computer-readable storage medium. A processor of a computer device reads the computer program from the computer-readable storage medium, and the processor executes the computer program, so that the computer device executes the permanent magnet synchronous motor current loop control method provided in the above-mentioned various optional implementations.

[0037] The technical solution provided by this application may have the following beneficial effects:

[0038] The vehicle converts the real-time current in the three-phase stationary coordinate system into the d-axis current and q-axis current in the two-phase rotating coordinate system. The d-axis current and q-axis current can reflect the actual operating status of the vehicle's motor. The corresponding voltage signal is generated based on the d-axis current and q-axis current, the motor speed and the current command, and the decoupling operation is performed to eliminate the cross-coupling effect, ensuring that the motor can operate stably under different working conditions. The overcurrent fault flag is obtained according to the d-axis and q-axis currents, which further enhances the safety of the motor during operation. The PWM switching frequency and the current loop PI controller parameters are determined according to the actual speed of the motor, and the dynamic response speed and accuracy of the motor are optimized. The motor is comprehensively controlled by combining all the above information (d-axis command voltage, q-axis command voltage, overcurrent fault flag, PWM switching frequency and current loop PI controller parameters), thereby achieving more precise and stable control of the permanent magnet synchronous motor, thereby effectively improving the control efficiency of the current loop.

[0039] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0041] Figure 1 is a system configuration diagram of a permanent magnet synchronous motor current loop control method involved in one embodiment of the present application;

[0042] Figure 2 This is a flow chart of a permanent magnet synchronous motor current loop control method provided by an embodiment of the present application;

[0043] Figure 3 This is a flow chart of a permanent magnet synchronous motor current loop control method provided by an embodiment of the present application;

[0044] Figure 4 This is a flow chart of a permanent magnet synchronous motor current loop control method provided by an embodiment of the present application;

[0045] Figure 5 is a schematic diagram of the system architecture of current loop control provided by an embodiment of the present application;

[0046] Figure 6 It is a schematic diagram of the software architecture of current control provided by an embodiment of the present application;

[0047] Figure 7 It is a schematic diagram of the software architecture of current control provided by an embodiment of the present application;

[0048] Figure 8 is a block diagram of a permanent magnet synchronous motor current loop control device provided by an exemplary embodiment of the present application;

[0049] Fig. 9 It is a structural diagram of a computer device provided by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0050] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0051] Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as recited in the appended claims.

[0052] Figure 1 1 is a system configuration diagram of a permanent magnet synchronous motor current loop control method according to an embodiment of the present application. Figure 1 As shown, the vehicle 100 includes a motor 100 a and a motor control system 100 b , the motor 100 a includes a permanent magnet synchronous motor stator winding 10 , and the motor control system 100 b includes a permanent magnet synchronous motor current loop 11 .

[0053] In an embodiment of the present application, the vehicle 100 can obtain the real-time current (three-phase current) and the motor speed of the permanent magnet synchronous motor stator winding 10 of the vehicle 100 in a three-phase stationary coordinate system, and convert the real-time current (three-phase current) in the three-phase stationary coordinate system into the d-axis current and q-axis current in a two-phase rotating coordinate system; generate a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the motor speed, and the current command for indicating the expected d-axis voltage signal and the expected q-axis voltage signal; perform a decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain the d-axis command voltage and the q-axis command voltage; obtain an overcurrent fault flag according to the d-axis current and the q-axis current; determine the PWM switching frequency and the current loop PI controller parameters based on the motor speed; and control the permanent magnet synchronous motor current loop 11 in the vehicle according to the d-axis command voltage, the q-axis command voltage, the overcurrent fault flag, the PWM switching frequency, and the current loop PI controller parameters.

[0054] It should be noted that in the embodiment of the present application and the following embodiments, the “motor” refers to a “permanent magnet synchronous motor”; the “current loop” refers to a “permanent magnet synchronous motor current loop”.

[0055] For example, please refer to Figure 2 , Figure 2 This is a flow chart of a permanent magnet synchronous motor current loop control method provided by an embodiment of the present application. Figure 2 The permanent magnet synchronous motor current loop control method shown can be executed by a vehicle, for example, the vehicle can be the above-mentioned Figure 1 The vehicle 100 shown; Figure 2 As shown, the permanent magnet synchronous motor current loop control method may include step 210, step 220, step 230, step 240, step 250, step 260 and step 270, which are specifically implemented as follows.

[0056] Step 210: Acquire the real-time current of the stator winding of the permanent magnet synchronous motor of the vehicle in a three-phase stationary coordinate system.

[0057] Among them, the real-time current in the above-mentioned three-phase stationary coordinate system refers to the actual current value of the three-phase windings A, B, and C in the stator winding of the above-mentioned permanent magnet synchronous motor at a certain moment.

[0058] In an embodiment of the present application, the vehicle can collect the current of the A, B, and C three-phase windings through a current sensor (for example, a Hall effect sensor) installed on the stator winding of the permanent magnet synchronous motor.

[0059] Step 220: Convert the real-time current in the three-phase stationary coordinate system into the d-axis current and the q-axis current in the two-phase rotating coordinate system.

[0060] The d-axis current (direct-axis current) is consistent with the direction of the rotor magnetic field of the motor and mainly affects the magnetic flux of the motor. The vehicle can adjust the magnetic flux of the motor by controlling the d-axis current, thereby affecting the performance of the motor.

[0061] The q-axis current (quadrature-axis current) is perpendicular to the direction of the rotor magnetic field and mainly affects the electromagnetic torque of the motor. The vehicle can achieve precise control of the motor torque by controlling the q-axis current.

[0062] In an embodiment of the present application, the vehicle may first convert the current in a three-phase stationary coordinate system into the current in a two-phase stationary coordinate system, and then convert the current in the two-phase stationary coordinate system into the current in a two-phase rotating coordinate system.

[0063] Step 230: Generate a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the motor speed and the current command; the current command is used to indicate the expected d-axis voltage signal and the expected q-axis voltage signal.

[0064] The motor speed refers to the number of revolutions per minute of the motor rotor of the vehicle.

[0065] The expected d-axis voltage signal and the expected q-axis voltage signal are the expected output d-axis voltage signal and q-axis voltage signal.

[0066] The above current command is used to instruct the motor controller to generate a corresponding voltage signal to achieve the desired motor performance.

[0067] In an embodiment of the present application, the vehicle can generate a d-axis voltage signal and a q-axis voltage signal according to a current command and actually measured d-axis current and q-axis current through a current loop PI controller.

[0068] Step 240: performing a decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage.

[0069] In an embodiment of the present application, the vehicle can compare the collected d-axis current and q-axis current with a preset current command value through a motor controller. For the d-axis current, a preliminary voltage adjustment value is calculated through a PI controller. The voltage adjustment value is used to make the d-axis current approach the target value. The d-axis voltage deviation is calculated through the mathematical model of the motor, combined with the current q-axis current value, motor speed, and motor inductance and other parameters. The preliminary voltage adjustment value is superimposed on the d-axis voltage deviation to obtain the d-axis command voltage. For the q-axis current, the vehicle obtains a preliminary voltage adjustment value through a PI controller, calculates the q-axis voltage deviation caused by the coupling effect and superimposes them to obtain the q-axis command voltage.

[0070] Step 250: Obtain an overcurrent fault flag according to the d-axis current and the q-axis current.

[0071] The overcurrent fault flag is a flag for indicating whether the current (d-axis current and q-axis current) of the motor exceeds a safety threshold.

[0072] In an embodiment of the present application, when the vehicle's motor is running, the vehicle monitors the magnitude of the d-axis current and the q-axis current in real time, and compares the d-axis current and the q-axis current with their respective set maximum allowable current thresholds. When any of the d-axis current and the q-axis current exceeds the maximum allowable current threshold, the vehicle determines that an overcurrent fault has occurred in the motor, and sets the overcurrent fault flag to "1", indicating that an overcurrent condition currently exists; if the d-axis current and the q-axis current are both within the normal range, the vehicle keeps the overcurrent fault flag at "0", indicating that the current current is normal.

[0073] Step 260: Determine the PWM switching frequency and current loop PI controller parameters based on the motor speed.

[0074] Among them, the above-mentioned PWM is a technology that uses digital signals to control analog circuits. It can adjust the output voltage by changing the duty cycle of the pulse and is widely used in fields such as motor control.

[0075] The PWM switching frequency is the frequency at which the PWM signal changes from a high level to a low level and then returns to a high level in one cycle, and the unit is Hz.

[0076] The above-mentioned current loop PI controller is a commonly used control algorithm, which can adjust the current through two parameters: proportional (P) and integral (I).

[0077] In an embodiment of the present application, the vehicle is provided with a mapping table, which contains a mapping relationship between the motor speed, the PWM switching frequency, and the current loop PI controller parameters. After obtaining the motor speed, the vehicle queries the mapping table to obtain the PWM switching frequency and the current loop PI controller parameters corresponding to the motor speed.

[0078] Step 270: Control the permanent magnet synchronous motor current loop in the vehicle according to the d-axis voltage signal, the q-axis voltage signal, the overcurrent fault flag, the PWM switching frequency, and the current loop PI controller parameters.

[0079] In an embodiment of the present application, the vehicle converts the real-time current in a three-phase stationary coordinate system into a d-axis current and a q-axis current in a two-phase rotating coordinate system. The d-axis current and the q-axis current can reflect the actual operating status of the vehicle's motor. A corresponding voltage signal is generated based on the d-axis current and the q-axis current, the motor speed and the current command, and a decoupling operation is performed to eliminate the influence of cross-coupling, thereby ensuring that the motor can operate stably under different operating conditions. An overcurrent fault flag is obtained based on the d-axis and q-axis currents, thereby further enhancing the safety of the motor during operation. The PWM switching frequency and the current loop PI controller parameters are determined based on the actual speed of the motor, thereby optimizing the dynamic response speed and accuracy of the motor. The motor is comprehensively controlled by combining all the above information (d-axis command voltage, q-axis command voltage, overcurrent fault flag, PWM switching frequency and current loop PI controller parameters), thereby achieving more precise and stable control of the permanent magnet synchronous motor, thereby effectively improving the control efficiency of the current loop.

[0080] Based on the above Figure 2 , please refer to Figure 3 , Figure 3 2 is a flow chart of a permanent magnet synchronous motor current loop control method provided by an embodiment of the present application. The above step 260 can be implemented as step 260a and step 260b, as follows.

[0081] Step 260a: Based on the motor speed, determine the operating range corresponding to the motor speed; the operating range is one of an acceleration range, a rated operating range, a constant power range, a deceleration range, a low speed operating range and a high speed operating range.

[0082] The motor speed is the actual current rotation speed of the motor, which is usually measured by an encoder or a resolver.

[0083] The above-mentioned operating ranges are different working states divided according to the motor speed of the vehicle.

[0084] For example, assume that the preset operating range can be an acceleration range (e.g., 0 to 500RPM), a rated operating range (e.g., 500 to 2000RPM), a constant power range (e.g., 2000 to 3000RPM), a deceleration range (e.g., 4000 to 0RPM), a low-speed operating range (e.g., 0 to 200RPM), and a high-speed operating range (e.g., 3000 to 4000RPM).

[0085] In an embodiment of the present application, a mapping table may be stored in the vehicle, the mapping table including different operating intervals and motor speed intervals corresponding to the operating intervals. The vehicle may monitor the motor speed in real time, query the mapping table based on the monitored motor speed, obtain the operating interval corresponding to the motor speed in the mapping table, and obtain the operating interval as the current operating interval of the motor.

[0086] Step 260b: Determine the PWM switching frequency and current loop PI controller parameters based on the operation range.

[0087] In an embodiment of the present application, a correspondence table can be preset in the vehicle, and the correspondence table is used to store the correspondence between different operating ranges of the motor and their corresponding PWM switching frequencies and current loop PI controller parameters. After the vehicle determines the operating range of the motor, it queries the pre-set correspondence table to obtain the PWM switching frequency and PI controller parameters corresponding to the operating range.

[0088] In the embodiment of the present application, the vehicle accurately identifies the current operating range of the motor by comparing the motor speed with multiple preset speed ranges, ensuring that the vehicle can respond accurately to different operating conditions, and queries the corresponding PWM switching frequency and PI controller parameters according to the determined operating range, so that the vehicle can automatically adjust and optimize the permanent magnet synchronous motor current loop parameters under different operating conditions, thereby improving the overall control efficiency of the permanent magnet synchronous motor current loop.

[0089] Based on the schemes shown in any one or more of the above embodiments, in some embodiments, the above step 260a can be implemented as: comparing the motor speed with at least one preset speed interval; when the motor speed meets the specified speed interval, obtaining the specified speed interval as the operating interval corresponding to the motor speed.

[0090] In an embodiment of the present application, the vehicle monitors the motor speed in real time and compares the monitored motor speed with multiple preset speed intervals. When the motor speed meets a preset speed interval, the speed interval is identified as the operating interval corresponding to the current motor.

[0091] For example, the vehicle detects that the motor speed is 1500RPM and identifies the motor speed as the rated operating range.

[0092] The above step 260b can be implemented as follows: according to the operating range, query the corresponding relationship between the operating range and the PWM switching frequency and the current loop PI controller parameters, and obtain the PWM switching frequency and the current loop PI controller parameters corresponding to the operating range.

[0093] In an embodiment of the present application, by comparing the motor speed with at least one preset speed range, the operating range of the current motor can be accurately identified to ensure that the vehicle can respond accurately to different operating conditions. When the motor speed meets a certain specified speed range, the range is obtained as the operating range corresponding to the motor speed, and the corresponding PWM switching frequency and current loop PI controller parameters are queried according to the operating range. The control parameters of the permanent magnet synchronous motor current loop control are obtained in real time through the motor speed, which can effectively improve the control efficiency of the permanent magnet synchronous motor current loop.

[0094] Based on the scheme shown in any one or more of the above-mentioned embodiments, in some embodiments, the vehicle determines the switching speed hysteresis value of the motor based on the operating range; the switching speed hysteresis value is the buffer speed threshold when the motor switches between different speed ranges; according to the absolute value of the motor speed, the switching speed hysteresis value and the switching speed value, the correspondence between the operating range and the PWM switching frequency and the current loop PI controller parameters is queried to determine the PWM switching frequency and the current loop PI controller parameters; the switching speed value is the speed critical value when the motor switches between different speed ranges.

[0095] The switching speed hysteresis value is a buffer speed threshold when the motor switches between different speed ranges, and is used to avoid instability caused by frequent switching of the motor.

[0096] The switching speed value is a critical speed value when the motor switches between different speed intervals, and is used to determine the time to switch from one interval to another.

[0097] The PI controller parameters are proportional and integral gains, which are used to adjust the dynamic response characteristics of the current loop. The proportional gain (Kp) affects the response speed of the system, and the integral gain (Ki) is used to eliminate steady-state errors.

[0098] In the embodiment of the present application, each of the above speed intervals is set with a switching speed hysteresis value.

[0099] For example, assuming that the switching speed difference between the acceleration range and the rated operating range is 50RPM, when the motor speed increases from 450RPM to 500RPM, it will not switch to the rated operating range immediately, but will wait until the motor speed exceeds 550RPM.

[0100] In the embodiment of the present application, the vehicle queries a preset correspondence table according to the determined operating range to obtain the PWM switching frequency and PI controller parameters corresponding to the operating range. The above correspondence table stores the operating range and the PWM switching frequency and PI controller parameters corresponding to the operating range; different operating ranges correspond to different PWM switching frequencies and PI controller parameters. For example, a lower switching frequency (e.g., 5kHz) and a larger integral gain (e.g., Ki=0.1) are selected in the acceleration range, and a higher switching frequency (e.g., 10kHz) and a smaller proportional gain (e.g., Kp=0.5) are selected in the rated operating range.

[0101] In an embodiment of the present application, the vehicle determines the buffer speed threshold when the motor switches between different speed ranges based on the motor speed, which can ensure that the motor is more stable during the switching process. By combining the absolute value of the motor speed, the switching speed hysteresis value and the switching speed value, the correspondence between the operating range and the PWM switching frequency and the current loop PI controller parameters is queried, and the control parameters required for the current motor can be accurately determined. Through the adaptive adjustment mechanism, the motor can run efficiently and smoothly under various working conditions, achieving more accurate and reliable control of the permanent magnet synchronous motor, thereby improving the stability of the current loop control of the permanent magnet synchronous motor.

[0102] Based on the schemes shown in any one or more of the above-mentioned embodiments, in some embodiments, when the sum of the switching speed hysteresis value and the switching speed value of the vehicle is less than the absolute value of the motor speed, the PWM switching frequency and the current loop PI controller parameters corresponding to the operating interval that is one level higher than the operating interval are queried and obtained; when the sum of the switching speed hysteresis value and the switching speed value is greater than the absolute value of the motor speed, the PWM switching frequency and the current loop PI controller parameters corresponding to the operating interval that is one level lower than the operating interval are queried and obtained.

[0103] In an embodiment of the present application, the lower level mentioned above may represent a lower speed range, a lower power output or a more relaxed control strategy of the motor; the higher level mentioned above may represent a higher speed range, a higher power output or a more stringent control strategy of the motor.

[0104] Exemplarily, the operating range levels of the above motor may be arranged from low to high as follows: acceleration range, rated operating range, constant power range and high-speed operating range.

[0105] The operating range one level higher than the operating range refers to an operating range one level higher than the operating range obtained when the current operating range of the motor is a certain level, and the operating range is an operating range of a higher level than the current operating range of the motor. For example, if the current operating range of the motor is a rated operating range, the operating range one level higher than the operating range may be a constant power range or a high-speed operating range.

[0106] The operating range one level lower than the operating range refers to an operating range one level lower than the operating range obtained when the current operating range of the motor is a certain level, and the operating range is an operating range of a lower level than the current operating range of the motor. For example, if the current operating range of the motor is the rated operating range, the operating range one level lower than the operating range may be a low-speed operating range.

[0107] In an embodiment of the present application, when the motor speed approaches a critical value, the vehicle determines to use control parameters corresponding to a higher or lower operating range based on the relationship between the sum of the switching speed hysteresis value and the switching speed value and the absolute value of the motor speed. If the sum of the switching speed hysteresis value and the switching speed value of the motor is less than the absolute value of the motor speed, the vehicle selects parameters that are one level higher than the current motor operating range; otherwise, the vehicle selects parameters that are one level higher than the current motor operating range, effectively avoiding instability caused by rapid switching of the motor, providing a smoother transition, and achieving more precise and reliable control of the permanent magnet synchronous motor, effectively improving the control efficiency of the permanent magnet synchronous motor current loop during switching between different speed ranges.

[0108] For example, based on Figure 2 , please refer to Figure 4 , Figure 4 2 is a flow chart of a permanent magnet synchronous motor current loop control method provided by an embodiment of the present application. The above step 220 can be implemented as step 220a and step 220b, as follows.

[0109] Step 220a: Convert the current in the three-phase stationary coordinate system into the current in the two-phase stationary coordinate system by Clarke transformation.

[0110] In the embodiment of the present application, the function of the above-mentioned Clarke transformation is to convert the current in the three-phase stationary coordinate system into the current in the two-phase stationary coordinate system. The Clarke transformation is based on the specific mathematical relationship between the three-phase currents of the motor, and realizes the conversion through specific matrix operations, which can simplify the subsequent control algorithm structure. In the three-phase stationary coordinate system, the expression of the current involves three variables. In the converted two-phase stationary coordinate system, the variables are reduced to two, which is equivalent to preliminarily converting a complex three-dimensional problem into a relatively simple two-dimensional problem, which is conducive to the subsequent vehicle analysis of the data.

[0111] Step 220b: Convert the two-phase stationary coordinate system current into the d-axis and q-axis currents in the two-phase synchronous rotating coordinate system through Park transformation.

[0112] In the embodiment of the present application, the above-mentioned Park transformation is to further convert the two-phase stationary coordinate system current into the d-axis and q-axis currents in the two-phase synchronous rotating coordinate system. In a permanent magnet synchronous motor, the d-axis current is closely related to the torque generation of the motor, and the q-axis current is related to the magnetic field orientation of the motor. The Park transformation is a mathematical transformation relationship constructed based on the synchronous rotating magnetic field characteristics of the motor. Through the Park transformation, the current based on the stationary coordinate system is converted to a coordinate system that rotates synchronously with the motor rotor, so that the vehicle can directly and effectively adjust the key physical quantities such as the electromagnetic torque and magnetic flux of the motor, thereby accurately controlling the motor's performance indicators such as speed and torque.

[0113] In an embodiment of the present application, the vehicle converts the current in a three-phase stationary coordinate system into a two-phase stationary coordinate system current through Clarke transformation, which simplifies the representation of current information and makes it easier to process. The two-phase stationary coordinate system current is further converted into d-axis and q-axis currents in a two-phase synchronous rotating coordinate system through Park transformation, so that the current information can more intuitively reflect the actual operating status of the motor. It not only eliminates the mutual coupling between the three-phase currents, but also enables the vehicle to independently adjust the d-axis and q-axis currents to achieve precise control of the motor magnetic field and torque, effectively ensuring the accuracy and reliability of the d-axis and q-axis current acquisition.

[0114] Based on the above Figures 2 to 4 The steps in the embodiments of the present application illustrate a design method for current loop control of a motor controller.

[0115] For example, please refer to Figure 5 , Figure 5 It is a schematic diagram of the system architecture of the current loop control provided by an embodiment of the present application.

[0116] For example, please refer to Figure 6 , Figure 6 It is a schematic diagram of the software architecture of current control provided by an embodiment of the present application.

[0117] For example, please refer to Figure 7 , Figure 7 It is a schematic diagram of the software architecture of current control provided by an embodiment of the present application.

[0118] Combination Figures 5 to 7 As shown, the current in the three-phase stationary coordinate system input after signal processing can be converted into the d and q axis current in the two-phase rotating coordinate system through Clarke and Park transformation; the input current command and feedback current are input into the PI regulator to obtain the voltage signals of the d and q axes, and the voltage signal is decoupled to obtain the final output signal. The dq axis command current, U, V, W three-phase current signal sampling loop fault, zero drift fault flag, drive state value, test value, U, V, W three-phase current signal, motor speed, current motor speed absolute value, electrical angle input current control are used to obtain the output dq axis command voltage, PWM switching frequency, overcurrent fault flag, and the current loop is controlled according to the output dq axis command voltage, PWM switching frequency, and overcurrent fault flag.

[0119] The embodiments of the present application mainly include the following two aspects: current PI control strategy switching frequency and current loop PI parameter adjustment.

[0120] In an embodiment of the present application, the switching frequency and current loop PI parameter adjustment module divides the motor control operation interval according to the speed, and switches the PWM switching frequency and current loop PI controller parameters in different operation intervals. Taking into account the speed fluctuation, a certain switching speed hysteresis is set when switching between different speed sections. Different speed sections and their corresponding PWM switching frequencies and PI controller parameters as well as the switching speed hysteresis can be calibrated by calibration software. The calibration strategy is as follows.

[0121] When the absolute value of the speed > switching speed (low to high) + switching speed hysteresis, it jumps to a higher speed, and the output is a higher PI parameter and PWM frequency;

[0122] When the absolute value of the speed is less than the switching speed (high to low) + the switching speed hysteresis, it jumps to a lower speed, and the output is a lower PI parameter and PWM frequency.

[0123] In the embodiment of the present application, when the speed of the motor is higher, in order to achieve satisfactory control performance, the PWM switching frequency is correspondingly increased; and from the perspective of reducing switching losses and IGBT temperature, the switching frequency is reduced as much as possible while meeting the control performance; the switching frequency and current loop PI parameter adjustment module determines the division of the motor control operation range according to the speed, switches the PWM switching frequency and current loop PI controller parameters in different operation ranges, and the operating conditions of the motor determine the corresponding PWM frequency; when performing current loop PI parameter adjustment, the current loop PI parameters corresponding to the motor are determined according to the operating conditions of the motor.

[0124] Please refer to Figure 8 , which shows a block diagram of a permanent magnet synchronous motor current loop control device provided by an exemplary embodiment of the present application. The permanent magnet synchronous motor current loop control device can be implemented as all or part of a computer device by hardware or a combination of hardware and software to achieve the above Figures 2 to 4 All or part of the steps in the embodiments shown. Figure 8 As shown, the permanent magnet synchronous motor current loop control device includes:

[0125] The current acquisition module 801 is used to acquire the real-time current of the stator winding of the permanent magnet synchronous motor of the vehicle in a three-phase stationary coordinate system;

[0126] A coordinate transformation module 802, used to transform the real-time current in the three-phase stationary coordinate system into the d-axis current and the q-axis current in the two-phase rotating coordinate system;

[0127] The voltage signal generating module 803 is used to generate a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the motor speed and the current command; the current command is used to indicate the expected d-axis voltage signal and the expected q-axis voltage signal;

[0128] A decoupling operation execution module 804 is used to execute a decoupling operation on a d-axis voltage signal and a q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage;

[0129] An overcurrent fault flag acquisition module 805 is used to acquire an overcurrent fault flag according to the d-axis current and the q-axis current;

[0130] A parameter determination module 806, configured to determine a PWM switching frequency and current loop PI controller parameters based on the motor speed;

[0131] The current loop control module 808 is used to control the permanent magnet synchronous motor current loop in the vehicle according to the d-axis voltage signal, the q-axis voltage signal, the overcurrent fault flag, the PWM switching frequency and the current loop PI controller parameters.

[0132] In some embodiments, the parameter determination module 806 is used to determine the operating interval corresponding to the motor speed based on the motor speed; the operating interval is one of an acceleration interval, a rated operating interval, a constant power interval, a deceleration interval, a low speed operating interval and a high speed operating interval;

[0133] Based on the operating range, the PWM switching frequency and the current loop PI controller parameters are determined.

[0134] In some embodiments, the parameter determination module 806 is used to compare the motor speed with at least one preset speed interval;

[0135] When the motor speed meets the specified speed range, the specified speed range is obtained as the operating range corresponding to the motor speed;

[0136] Based on the operating range, determine the PWM switching frequency and current loop PI controller parameters, including:

[0137] According to the operating range, the corresponding relationship between the operating range and the PWM switching frequency and the current loop PI controller parameters is queried to obtain the PWM switching frequency and the current loop PI controller parameters corresponding to the operating range.

[0138] In some embodiments, the parameter determination module 806 is used to determine the switching speed hysteresis value of the motor based on the operation interval; the switching speed hysteresis value is a buffer speed threshold when the motor switches between different speed intervals;

[0139] According to the absolute value of the motor speed, the switching speed hysteresis value and the switching speed value, the correspondence between the operating range and the PWM switching frequency and the current loop PI controller parameters is queried to determine the PWM switching frequency and the current loop PI controller parameters; the switching speed value is the critical speed value when the motor switches between different speed ranges.

[0140] In some embodiments, the parameter determination module 806 is used to query and obtain the PWM switching frequency and the current loop PI controller parameter corresponding to the operating interval one level higher than the operating interval in the corresponding relationship between the operating interval and the PWM switching frequency and the current loop PI controller parameter when the sum of the switching speed hysteresis value and the switching speed value is less than the absolute value of the motor speed;

[0141] When the sum of the switching speed hysteresis value and the switching speed value is greater than the absolute value of the motor speed, the PWM switching frequency and the current loop PI controller parameters corresponding to the operating interval that is one level lower than the operating interval are queried to obtain the corresponding relationship between the operating interval and the PWM switching frequency and the current loop PI controller parameters.

[0142] In some embodiments, the coordinate transformation module 802 is used to transform the current in the three-phase stationary coordinate system into the current in the two-phase stationary coordinate system through Clarke transformation;

[0143] The two-phase stationary coordinate system current is converted into the d-axis and q-axis currents in the two-phase synchronous rotating coordinate system through Park transformation.

[0144] Please refer to Fig. 9 , Fig. 9 9 is a schematic diagram of the structure of a computer device provided by an exemplary embodiment of the present application. The computer device 900 includes a central processing unit (CPU) 901, a system memory 904 including a random access memory (RAM) 902 and a read-only memory (ROM) 903, and a system bus 905 connecting the system memory 904 and the central processing unit 901. The computer device 900 also includes a basic input / output system (I / O system) 906 that helps transmit information between various devices in the computer, and a large-capacity storage device 907 for storing an operating system 913, application programs 914 and other program modules 915.

[0145] The basic input / output system 906 includes a display 908 for displaying information and an input device 909 such as a mouse and a keyboard for user inputting information. The display 908 and the input device 909 are connected to the central processing unit 901 through an input / output controller 910 connected to the system bus 905. The basic input / output system 906 may also include an input / output controller 910 for receiving and processing inputs from a plurality of other devices such as a keyboard, a mouse, or an electronic stylus. Similarly, the input / output controller 910 also provides output to a display screen, a printer, or other types of output devices.

[0146] The mass storage device 907 is connected to the central processing unit 901 through a mass storage controller (not shown) connected to the system bus 905. The mass storage device 907 and its associated computer readable media provide non-volatile storage for the computer device 900. That is, the mass storage device 907 may include a computer readable medium (not shown) such as a hard disk or a CD-ROM (Compact Disc Read-Only Memory) drive.

[0147] Without loss of generality, computer readable media may include computer storage media and communication media. Computer storage media include volatile and non-volatile, removable and non-removable media implemented by any method or technology for storing information such as computer readable instructions, data structures, program modules or other data. Computer storage media include RAM (Random Access Memory), ROM (Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory or other solid-state storage technologies, CD-ROM, DVD (Digital Video Disc) or other optical storage, cassettes, tapes, disk storage or other magnetic storage devices. Of course, those skilled in the art will appreciate that computer storage media are not limited to the above. The above-mentioned system memory 904 and mass storage device 907 can be collectively referred to as memory.

[0148] The computer device 900 can be connected to the Internet or other network devices through a network interface unit 911 connected to the system bus 905 .

[0149] The memory also includes one or more programs, one or more programs are stored in the memory, and the central processing unit 901 implements the one or more programs by executing the one or more programs. Figures 2 to 4 All or part of the steps in the method shown.

[0150] In an exemplary embodiment, a chip is also provided. The chip includes a programmable logic circuit and / or program instructions. When the chip runs on a computer device, it is used to implement all or part of the steps of the method shown in the above embodiments of the present application.

[0151] In an exemplary embodiment, a computer program product is also provided, the computer program product includes computer instructions, the computer instructions are stored in a computer-readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor reads and executes the computer instructions from the computer-readable storage medium to implement all or part of the steps of the method shown in the above-mentioned various embodiments of the present application.

[0152] In an exemplary embodiment, a computer-readable storage medium is also provided, in which a computer program is stored. The computer program is loaded and executed by a processor to implement all or part of the steps of the method shown in the above-mentioned embodiments of the present application.

[0153] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware or by instructing related hardware through a program. The above program may be stored in a computer-readable storage medium. The above storage medium may be a read-only memory, a disk or an optical disk, etc.

[0154] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented with hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein the communication media include any media that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that a general or special-purpose computer can access.

[0155] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A permanent magnet synchronous motor current loop control method, characterized in that: The method is performed by a vehicle, and comprises: Acquire the real-time current in a three-phase stationary coordinate system of the stator winding of the permanent magnet synchronous motor of the vehicle; Converting the real-time current in the three-phase stationary coordinate system into a d-axis current and a q-axis current in a two-phase rotating coordinate system; Generate a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the motor speed and the current command; the current command is used to indicate the expected d-axis voltage signal and the expected q-axis voltage signal; Performing a decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage; Acquire an overcurrent fault flag bit according to the d-axis current and the q-axis current; Determine the PWM switching frequency and the current loop PI controller parameters based on the motor speed; The permanent magnet synchronous motor current loop in the vehicle is controlled according to the d-axis command voltage, the q-axis command voltage, the overcurrent fault flag, the PWM switching frequency and the current loop PI controller parameters.

2. The method according to claim 1, characterized in that The method of determining the PWM switching frequency and the current loop PI controller parameters based on the motor speed includes: Based on the motor speed, determining an operating interval corresponding to the motor speed; the operating interval is one of an acceleration interval, a rated operating interval, a constant power interval, a deceleration interval, a low-speed operating interval, and a high-speed operating interval; Based on the operation range, the PWM switching frequency and the current loop PI controller parameters are determined.

3. The method according to claim 2, characterized in that The step of determining the operating range corresponding to the motor speed based on the motor speed includes: Comparing the motor speed with at least one preset speed interval; When the motor speed satisfies a specified speed interval, obtaining the specified speed interval as an operating interval corresponding to the motor speed; The determining of the PWM switching frequency and the current loop PI controller parameters based on the operating range includes: According to the operating range, the corresponding relationship between the operating range and the PWM switching frequency and the current loop PI controller parameters is queried to obtain the PWM switching frequency and the current loop PI controller parameters corresponding to the operating range.

4. The method according to claim 3, characterized in that The querying, based on the operating interval, of the corresponding relationship between the operating interval and the PWM switching frequency and the current loop PI controller parameter to obtain the PWM switching frequency and the current loop PI controller parameter corresponding to the operating interval includes: Based on the operation interval, determining a switching speed hysteresis value of the motor; the switching speed hysteresis value is a buffer speed threshold when the motor switches between different speed intervals; According to the absolute value of the motor speed, the switching speed hysteresis value and the switching speed value, the correspondence between the operating range and the PWM switching frequency and the current loop PI controller parameters is queried to determine the PWM switching frequency and the current loop PI controller parameters; the switching speed value is the speed critical value when the motor switches between different speed ranges.

5. The method according to claim 4, characterized in that The step of querying the correspondence between the operating range and the PWM switching frequency and the current loop PI controller parameters according to the absolute value of the motor speed, the switching speed hysteresis value and the switching speed value, and determining the PWM switching frequency and the current loop PI controller parameters includes: In the case where the sum of the switching speed hysteresis value and the switching speed value is less than the absolute value of the motor speed, querying and obtaining the PWM switching frequency and the current loop PI controller parameter corresponding to the operating interval that is one level higher than the operating interval in the corresponding relationship between the operating interval and the PWM switching frequency and the current loop PI controller parameter; When the sum of the switching speed hysteresis value and the switching speed value is greater than the absolute value of the motor speed, the PWM switching frequency and the current loop PI controller parameters corresponding to the operating interval that is one level lower than the operating interval are queried to obtain the corresponding relationship between the operating interval and the PWM switching frequency and the current loop PI controller parameters.

6. The method according to claim 1, characterized in that The method of converting the real-time current in the three-phase stationary coordinate system into the d-axis current and the q-axis current in the two-phase rotating coordinate system comprises: The current in the three-phase stationary coordinate system is converted into the current in the two-phase stationary coordinate system by Clarke transformation; The two-phase stationary coordinate system current is converted into d-axis and q-axis currents in a two-phase synchronous rotating coordinate system through the Park transformation.

7. A permanent magnet synchronous motor current loop control device, characterized in that: The device comprises: A current acquisition module, used to acquire the real-time current in a three-phase stationary coordinate system of the stator winding of the permanent magnet synchronous motor of the vehicle; A coordinate transformation module, used for converting the real-time current in a three-phase stationary coordinate system into a d-axis current and a q-axis current in a two-phase rotating coordinate system; a voltage signal generating module, configured to generate a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the motor speed and a current command; the current command is used to indicate an expected d-axis voltage signal and an expected q-axis voltage signal; a decoupling operation execution module, used for executing a decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage; An overcurrent fault flag acquisition module, used to acquire an overcurrent fault flag according to the d-axis current and the q-axis current; A parameter determination module, used to determine the PWM switching frequency and the current loop PI controller parameters based on the motor speed; A current loop control module is used to control the permanent magnet synchronous motor current loop in the vehicle according to the d-axis command voltage, the q-axis command voltage, the overcurrent fault flag, the PWM switching frequency and the current loop PI controller parameters.

8. A computer device, characterized in that: The computer device includes a processor and a memory, wherein the memory stores instructions, and the instructions are executed by the processor to implement the permanent magnet synchronous motor current loop control method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The storage medium stores instructions, and the instructions are executed by a processor of a computer device to implement the permanent magnet synchronous motor current loop control method as described in any one of claims 1 to 6.

10. A computer program product, characterized in that The computer program product includes computer instructions, which are stored in a computer-readable storage medium; the computer instructions are read and executed by a processor of a computer device to implement the permanent magnet synchronous motor current loop control method as described in any one of claims 1 to 6.

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