Permanent magnet synchronous motor control method, device, equipment and storage medium
By constructing a voltage vector combination and objective function, the problem of limited torque accuracy control in electric drive systems was solved, achieving higher torque control accuracy and reducing the impact of motor parameter errors.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AVATR CO LTD
- Filing Date
- 2026-05-06
- Publication Date
- 2026-07-14
AI Technical Summary
The torque accuracy control of existing electric drive systems is limited, mainly because motor parameter errors are transmitted, accumulated and amplified in the control loop, resulting in a strong dependence on the current command calculation stage.
By determining the reference voltage based on the reference torque and current of the target motor, constructing a voltage vector combination, calculating the predicted current and predicted torque, constructing the objective function and solving for the modulation duty cycle, the current command calculation step is eliminated, avoiding the propagation and amplification of motor parameter errors.
This improves the torque control accuracy of the electric drive system, reduces the dependence on motor parameters, and enhances the torque control accuracy of the electric drive system.
Smart Images
Figure CN122394431A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of motor control technology, specifically to a method, apparatus, device, and storage medium for controlling a permanent magnet synchronous motor. Background Technology
[0002] To achieve maximum efficiency in an electric drive system, it is necessary to control the system to achieve maximum torque per ampere while maintaining torque accuracy. Currently, cascaded algorithms are commonly used to control electric drive systems. This process typically involves calculating or looking up the motor current and then using a PI controller to track the current. However, this method is heavily reliant on motor parameters, and errors in these parameters are propagated, accumulated, and amplified throughout the control loop, resulting in limited torque accuracy control of the electric drive system. Summary of the Invention
[0003] In view of the above problems, embodiments of the present invention provide a permanent magnet synchronous motor control method, device, equipment and storage medium to solve the problem of limited torque accuracy control of electric drive systems in the prior art.
[0004] According to one aspect of the present invention, a control method for a permanent magnet synchronous motor is provided, the method comprising: Determine the reference voltage of the target motor based on the reference torque and current of the target motor; Based on the phase information of the reference voltage of the target motor, determine the voltage vector combination of the reference voltage; Based on the current current and voltage vector combination of the target motor, the predicted current and predicted torque of the target motor are determined; Based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor, an objective function is constructed. The objective function is solved to obtain the target modulation duty cycle of the target motor, and the operation of the target motor is controlled based on the target modulation duty cycle.
[0005] In one alternative implementation, determining the reference voltage of the target motor based on the reference torque and current of the target motor includes: Construct the torque equation between the reference current and reference torque of the target motor; With the goal of minimizing the square of the current magnitude of the target motor, the torque equation is solved to obtain the reference current of the target motor; Determine the reference voltage of the target motor based on its current current and reference current.
[0006] In one optional implementation, the voltage vector combination includes a first voltage vector, a second voltage vector, and a third voltage vector. The voltage vector combination of the reference voltage is determined based on the phase information of the reference voltage of the target motor, including: Based on the phase information of the reference voltage, determine the sector where the reference voltage is located; The adjacent effective vectors corresponding to the sector where the reference voltage is located are respectively used as the first voltage vector and the second voltage vector of the reference voltage; Use the zero vector as the third voltage vector of the reference voltage.
[0007] In one alternative implementation, determining the predicted current and predicted torque of the target motor based on the current vector combination of the target motor includes: Based on the current current of the target motor and each voltage vector in the voltage vector combination, calculate the predicted current corresponding to each voltage vector; Based on the modulation duty cycle and predicted current corresponding to each voltage vector in the voltage vector combination, the predicted current of the target motor is determined. The predicted torque of the target motor is determined based on the predicted current of the target motor.
[0008] In one alternative implementation, an objective function is constructed based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor, including: The first sub-function is constructed based on the difference between the reference torque and the predicted torque; The second sub-function is constructed based on the sum of squares of the predicted current components in the predicted current. A third sub-function is constructed based on the sum of squares of the modulation duty cycle components. The objective function is obtained by weighting the first, second, and third sub-functions.
[0009] In one optional implementation, the objective function is solved to obtain the target modulation duty cycle of the target motor, including: Based on voltage vector combination and reference voltage, constraints on modulation duty cycle are constructed; Based on the constraint of modulation duty cycle, the objective function is solved with the goal of minimizing its value, and the target modulation duty cycle is obtained.
[0010] In one alternative implementation, constraints on the modulation duty cycle are constructed based on the voltage vector combination and the reference voltage, including: The constraints on the modulation duty cycle are constructed based on the sum of the products of each voltage vector in the voltage vector combination and the corresponding modulation duty cycle, as well as the product of the reference voltage and the sampling period.
[0011] According to another aspect of the present invention, a permanent magnet synchronous motor control device is provided, comprising: The reference voltage determination module is used to determine the reference voltage of the target motor based on the reference torque and current current of the target motor. The voltage vector determination module is used to determine the voltage vector combination of the reference voltage based on the phase information of the reference voltage of the target motor. The motor parameter prediction module is used to determine the predicted current and predicted torque of the target motor based on the current vector combination of the target motor and the voltage. The objective function construction module is used to construct the objective function based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor. The objective function solving module is used to solve the objective function, obtain the target modulation duty cycle of the target motor, and control the operation of the target motor based on the target modulation duty cycle.
[0012] According to another aspect of the present invention, an electronic device is provided, including: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other through the communication bus; The memory is used to store at least one executable instruction that causes the processor to perform the operation of the permanent magnet synchronous motor control method as described in any of the above embodiments.
[0013] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein at least one executable instruction is stored in the storage medium, which, when executed on a permanent magnet synchronous motor control device or electronic device, causes the permanent magnet synchronous motor control device or electronic device to perform the operation of the permanent magnet synchronous motor control method as described in any of the above embodiments.
[0014] According to another aspect of the present invention, a computer program product is provided, including computer instructions for causing a permanent magnet synchronous motor control device or electronic device to perform the operation of the permanent magnet synchronous motor control method as described in any of the above embodiments.
[0015] This invention determines the reference voltage of the target motor based on its reference torque and current current. Based on the phase information of the reference voltage, it determines the voltage vector combination of the reference voltage. Based on the current current and voltage vector combination, it determines the predicted current and predicted torque of the target motor. Based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor, an objective function is constructed and solved to obtain the target modulation duty cycle of the target motor. This eliminates the need to use the current command as the tracking target, thus eliminating the current command calculation stage in cascaded control, eliminating dependence on motor parameters, and preventing the transmission, accumulation, and amplification of motor parameter errors throughout the control loop. This improves the torque control accuracy of the electric drive system.
[0016] The above description is merely an overview of the technical solutions of the embodiments of the present invention. In order to better understand the technical means of the embodiments of the present invention and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description
[0017] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic flowchart of a first method for controlling a permanent magnet synchronous motor according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the second process of the permanent magnet synchronous motor control method according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the third process of the permanent magnet synchronous motor control method according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the fourth process of the permanent magnet synchronous motor control method according to an embodiment of the present invention; Figure 5 This is a structural block diagram of a permanent magnet synchronous motor control device according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation
[0018] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.
[0019] To achieve maximum efficiency in an electric drive system, it is necessary to control the system to achieve maximum torque per ampere while maintaining torque accuracy. Currently, cascaded algorithms are commonly used to control electric drive systems. This process typically involves calculating or looking up the motor current, then using a PI controller to track the current. The lookup method pre-calibrates the motor, measures and stores the optimal current combination for different torques, and then searches for the optimal current combination corresponding to the required torque. However, factors such as motor demagnetization or overheating can cause parameter shifts, rendering the table records no longer the true optimum. The calculation method uses the ideal torque equation, deriving the functional relationship of the current through differentiation. However, the ideal formula assumes a constant inductance, while in practical applications, motors often experience severe magnetic saturation and cross-coupling, causing the calculated results to deviate from the optimum. Therefore, current methods heavily rely on motor parameters, and the discrepancy between theoretical and actual motor parameter values causes the obtained current to deviate from the optimum. Furthermore, errors in motor parameters are propagated, accumulated, and amplified throughout the control loop, resulting in limited torque accuracy control of the electric drive system.
[0020] To address the aforementioned technical problems, this invention provides a permanent magnet synchronous motor control method. Based on the reference torque and current of the target motor, a reference voltage for the target motor is determined. Based on the phase information of the reference voltage, a voltage vector combination of the reference voltage is determined. Based on the current and voltage vector combination of the target motor, a predicted current and predicted torque of the target motor are determined. Based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor, an objective function is constructed and solved to obtain the target modulation duty cycle of the target motor. This eliminates the need to use current commands as the tracking target, thus removing the current command calculation stage in cascaded control and preventing the transmission, accumulation, and amplification of motor parameter errors throughout the control loop. This improves the torque control accuracy of the electric drive system.
[0021] According to an embodiment of the present invention, a method for controlling a permanent magnet synchronous motor is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.
[0022] This embodiment provides a control method for a permanent magnet synchronous motor. Figure 1 This is a schematic flowchart of the first method for controlling a permanent magnet synchronous motor according to an embodiment of the present invention, as shown below. Figure 1 As shown, the process includes the following steps: Step S101: Determine the reference voltage of the target motor based on the reference torque and current of the target motor.
[0023] In this embodiment of the invention, the target motor is a permanent magnet synchronous motor in the electric drive system currently undergoing torque control. The reference torque of the target motor is the torque that the electric drive system aims to achieve; in the vehicle control system, this reference torque can be provided by the on-board terminal or the vehicle controller. The current current of the target motor is the current of the target motor at the current moment, which can be obtained in real time using sampling circuits or sensors.
[0024] In this embodiment of the invention, the reference current of the target motor is obtained by reverse derivation of the torque equation based on the reference torque of the target motor. The reference voltage of the target motor is calculated by combining the current current of the target motor and the reference current and through current error compensation.
[0025] Step S102: Based on the phase information of the reference voltage of the target motor, determine the voltage vector combination of the reference voltage.
[0026] In this embodiment of the invention, SVPWM (Space Vector Pulse Width Modulation) sectors are used to determine the voltage vector combination of the reference voltage; wherein, the SVPWM sector determines the voltage vector combination of the reference voltage. The system is divided into six equal 60° regions, each corresponding to a sector. Each sector contains two voltage vectors located at its boundaries, forming a set of adjacent effective vectors. Based on the phase information of the target motor's reference voltage, the sector containing the reference voltage is determined. The voltage vector combination of the reference voltage is then obtained based on the set of adjacent effective vectors corresponding to the boundaries of the sector containing the reference voltage.
[0027] Step S103: Based on the current current and voltage vector combination of the target motor, determine the predicted current and predicted torque of the target motor.
[0028] In this embodiment of the invention, the predicted current of the target motor refers to the predicted current of the target motor at the next moment, and the predicted torque of the target motor refers to the predicted torque of the target motor at the next moment. For each voltage vector in the voltage vector combination, the predicted current under its individual action is calculated. Then, the predicted current corresponding to each voltage vector is weighted using the modulation duty cycle to obtain the predicted current of the target motor. After calculating the predicted current of the target motor, the predicted current of the target motor is substituted into the torque formula to obtain the predicted torque of the target motor.
[0029] Step S104: Construct the objective function based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor.
[0030] In this embodiment of the invention, an objective function is constructed based on the predicted current amplitude of the target motor, the deviation between the predicted torque and the reference torque, and the regularization term of the modulation duty cycle. The predicted current amplitude is used to suppress the stator current amplitude, thereby achieving maximum current-to-torque ratio control. The deviation between the predicted torque and the reference torque is used to ensure torque tracking accuracy. The regularization term of the modulation duty cycle is used to avoid extreme duty cycle values that could cause a surge in inverter switching losses.
[0031] Step S105: Solve the objective function to obtain the target modulation duty cycle of the target motor, and control the operation of the target motor based on the target modulation duty cycle.
[0032] In this embodiment of the invention, the objective function is solved with the goal of minimizing it to obtain the target modulation duty cycle of the target motor. The action order of each voltage vector in the voltage vector combination is allocated according to the conventional rules of SVPWM, and the action time of each voltage vector is controlled according to the target modulation duty cycle, thereby generating a switching signal sequence for the inverter. The inverter is switched according to this switching signal sequence in each sampling period, thereby controlling the operation of the target motor.
[0033] The permanent magnet synchronous motor control method provided in this invention determines the reference voltage of the target motor based on the reference torque and current of the target motor, determines the voltage vector combination of the reference voltage based on the phase information of the reference voltage of the target motor, and determines the predicted current and predicted torque of the target motor based on the current current and voltage vector combination of the target motor. Based on the predicted current, predicted torque, reference torque and modulation duty cycle of the target motor, an objective function is constructed and solved to obtain the target modulation duty cycle of the target motor. Therefore, the current command is no longer used as the tracking target, which can eliminate the current command calculation link in cascaded control and avoid the transmission, accumulation and amplification of motor parameter errors in the entire control loop, thereby improving the torque control accuracy of the electric drive system.
[0034] This embodiment provides a control method for a permanent magnet synchronous motor. Figure 2 This is a schematic diagram of the second type of permanent magnet synchronous motor control method according to an embodiment of the present invention, as shown below. Figure 2 As shown, the process includes the following steps: Step S201: Determine the reference voltage of the target motor based on the reference torque and current of the target motor.
[0035] Specifically, step S201 includes: Step S2011: Construct the torque equation between the reference current and reference torque of the target motor.
[0036] In this embodiment of the invention, the torque equation between the reference current and the reference torque of the target motor can be constructed as shown in the following formula (1): Formula (1) in, For reference torque, Let be the number of pole pairs of the target motor. For the permanent magnet flux linkage of the target motor, for Rotating coordinate system The reference current component of the shaft, for Rotating coordinate system The reference current component of the shaft, for Rotating coordinate system The inductive component of the shaft, for Rotating coordinate system The inductive component of the shaft.
[0037] In step S2012, with the goal of minimizing the square of the current magnitude of the target motor, the torque equation is solved to obtain the reference current of the target motor.
[0038] In this embodiment of the invention, the objective is to minimize the square of the current magnitude of the target motor, that is, to... To optimize the target, the torque equation constructed above is solved to obtain the reference current of the target motor, which includes... Rotating coordinate system The reference current component of the shaft and Reference current component of the axis.
[0039] In one alternative implementation, the equations between the reference currents can be obtained by using the Lagrange multiplier method, as shown in the following formula (2). Then, the equations can be solved by a numerical iteration method, such as the Newton-Raphson method, to obtain the reference current of the target motor.
[0040] , Formula (2) Step S2013: Determine the reference voltage of the target motor based on the current current and reference current of the target motor.
[0041] In this embodiment of the invention, based on the current current and reference current of the target motor, the reference voltage of the target motor is calculated through current error compensation, as shown in the following formula (3): Formula (3) in, for Rotating coordinate system The reference voltage component of the axis, for Rotating coordinate system The reference voltage component of the axis, Let be the stator resistance of the target motor. for Rotating coordinate system The current component of the axis. for Rotating coordinate system The current component of the axis. The sampling period for the target motor. Let be the electric angular velocity of the target motor.
[0042] In one optional implementation, the current current of the target motor is directly obtained as the three-phase current of the target motor. Before calculating the reference voltage using the current current and the reference current, the obtained three-phase current is converted to... A rotating coordinate system is used to facilitate subsequent calculations. Specifically, the three-phase currents are first converted to... In coordinate system, we obtain The current component in the coordinate system, and then Current component transformation in coordinate system to In the rotated coordinate system, we obtain The specific transformation process of the current component in the rotating coordinate system can be shown in the following formula (4): , Formula (4) in, )for coordinate system Current components of the shaft, for coordinate system Current components of the shaft, for Phase current, for Phase current, for Phase current, This indicates the rotor position.
[0043] Step S202: Based on the phase information of the reference voltage of the target motor, determine the voltage vector combination of the reference voltage. For details, please refer to [link to relevant documentation]. Figure 1 Step S102 of the illustrated embodiment will not be described again here.
[0044] Step S203: Based on the current vector combination of the target motor's current and voltage, determine the predicted current and predicted torque of the target motor. For details, please refer to [link to relevant documentation].Figure 1 Step S103 of the illustrated embodiment will not be described again here.
[0045] Step S204: Construct the objective function based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor. For details, please refer to [link to relevant documentation]. Figure 1 Step S104 of the illustrated embodiment will not be described again here.
[0046] Step S205: Solve the objective function to obtain the target modulation duty cycle of the target motor, and control the operation of the target motor based on the target modulation duty cycle. For details, please refer to [link to relevant documentation]. Figure 1 Step S105 of the illustrated embodiment will not be described again here.
[0047] The permanent magnet synchronous motor control method provided in this invention constructs a torque equation between the reference current and reference torque of the target motor. With the goal of minimizing the square of the current magnitude of the target motor, the torque equation is solved to obtain the reference current of the target motor. Thus, the maximum torque-to-current ratio control of the target motor is achieved under a given reference torque, enabling the electric drive system to operate at maximum efficiency.
[0048] This embodiment provides a control method for a permanent magnet synchronous motor. Figure 3 This is a schematic diagram of the third process of the permanent magnet synchronous motor control method according to an embodiment of the present invention, as shown below. Figure 3 As shown, the process includes the following steps: Step S301: Determine the reference voltage of the target motor based on its reference torque and current. For details, please refer to [link to relevant documentation]. Figure 1 Step S101 of the illustrated embodiment will not be described again here.
[0049] Step S302: Based on the phase information of the reference voltage of the target motor, determine the voltage vector combination of the reference voltage.
[0050] In this embodiment of the invention, the voltage vector combination includes a first voltage vector, a second voltage vector, and a third voltage vector. Correspondingly, step S302 includes: Step S3021: Based on the phase information of the reference voltage, determine the sector where the reference voltage is located.
[0051] In this embodiment of the invention, based on the phase information of the reference voltage, the angle of the voltage vector corresponding to the reference voltage is calculated, and the angle of the voltage vector corresponding to the reference voltage is compared with the angle range of each sector to determine the sector where the reference voltage is located. The angle range of each sector and the corresponding adjacent effective vectors can be shown in Table 1 below.
[0052] Table 1
[0053] In one alternative implementation, SVPWM sectors are based on The plane corresponding to the axis is divided, and the calculated reference voltage of the target motor is based on... By rotating the coordinate system, the reference voltage is transformed into a coordinate system before determining the sector containing the reference voltage based on its phase information. This is done through the inverse Park transform. Under the axis, the specific details can be shown in the following formula (5): Formula (5) in, for coordinate system The reference voltage component of the axis, for coordinate system The reference voltage component of the axis.
[0054] Step S3022: The adjacent effective vectors corresponding to the sector where the reference voltage is located are respectively used as the first voltage vector and the second voltage vector of the reference voltage.
[0055] In this embodiment of the invention, among the adjacent valid vectors corresponding to the sector where the reference voltage is located, the voltage vector with the smaller angle is taken as the first voltage vector of the reference voltage, and the voltage vector with the larger angle is taken as the second voltage vector of the reference voltage. That is, the voltage vector at the beginning of the sector where the reference voltage is located is taken as the first voltage vector of the reference voltage, and the voltage vector at the end of the sector where the reference voltage is located is taken as the second voltage vector of the reference voltage. For example, if the reference voltage is located in sector 1, then the first voltage vector of the reference voltage is V1, and the second voltage vector is V2.
[0056] Step S3023: Use the zero vector as the third voltage vector of the reference voltage.
[0057] In this embodiment of the invention, the zero vector is selected as the third voltage vector of the reference voltage. The zero vectors corresponding to the SVPWM sector include V0 and V7. The switching state corresponding to V0 is 000 and the switching state corresponding to V7 is 111. Either the voltage vector of V0 or V7 is selected as the third voltage vector of the reference voltage.
[0058] Step S303: Based on the current current and voltage vector combination of the target motor, determine the predicted current and predicted torque of the target motor.
[0059] Specifically, step S303 includes: Step S3031: Based on the current current of the target motor and each voltage vector in the voltage vector combination, calculate the predicted current corresponding to each voltage vector.
[0060] In this embodiment of the invention, a continuous-time model between the stator voltage and stator current of the target motor is established, as shown in the following formula (6): , Formula (6) in, for Rotating coordinate system Stator voltage component of the shaft, for Rotating coordinate system Stator voltage component of the shaft.
[0061] In this embodiment of the invention, the continuous-time model between stator voltage and stator current is discretized using the first-order forward Euler method, and the following is utilized: By rewriting the above continuous-time model, we obtain the following formula (7) for calculating the predicted current: , Formula (7) in, for Rotating coordinate system The predicted current component of the axis, for Rotating coordinate system Predicted current components of the axis.
[0062] In this embodiment of the invention, each voltage vector in the voltage vector combination is substituted into the above formula (7) to obtain the predicted current under the individual action of each voltage vector. The voltage vector obtained using the SVPWM sector is located in... Before substituting each voltage vector into the above formula (7), the Clarke transform and Park transform are first used to convert the voltage vectors based on the corresponding switching states, to obtain the following: The voltage component in the rotating coordinate system can be represented by the following formula (8): , Formula (8) in, The DC bus voltage of the target motor. , , These represent the on / off states of the inverter.
[0063] Step S3032: Determine the predicted current of the target motor based on the modulation duty cycle and predicted current corresponding to each voltage vector in the voltage vector combination.
[0064] In this embodiment of the invention, based on the modulation duty cycle corresponding to each voltage vector in the voltage vector combination, the predicted current corresponding to each voltage vector is weighted and calculated to obtain the predicted current of the target motor, as shown in the following formula (9): , Formula (9) in, Corresponding to the first voltage vector, The second voltage vector corresponds to 0, and the third voltage vector, i.e., the zero vector, corresponds to 0. The modulation duty cycle of the first voltage vector. The modulation duty cycle of the second voltage vector. The modulation duty cycle of the third voltage vector is given by, where, , , , The duration of the first voltage vector is... The duration of the second voltage vector's action. The duration of the third voltage vector; The corresponding first voltage vector Rotating coordinate system The predicted current component of the axis, The corresponding second voltage vector Rotating coordinate system The predicted current component of the axis, The corresponding third voltage vector Rotating coordinate system The predicted current component of the axis, The corresponding first voltage vector Rotating coordinate system The predicted current component of the axis, The corresponding second voltage vector Rotating coordinate system The predicted current component of the axis, The corresponding third voltage vector Rotating coordinate system Predicted current components of the axis.
[0065] Step S3033: Determine the predicted torque of the target motor based on the predicted current of the target motor.
[0066] In this embodiment of the invention, the predicted current of the target motor is substituted into the torque formula to obtain the predicted torque of the target motor, which can be specifically shown in the following formula (10): Formula (10) in, The predicted torque of the target motor.
[0067] Step S304: Construct the objective function based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor. For details, please refer to [link to relevant documentation]. Figure 1 Step S104 of the illustrated embodiment will not be described again here.
[0068] Step S305: Solve the objective function to obtain the target modulation duty cycle of the target motor, and control the operation of the target motor based on the target modulation duty cycle. For details, please refer to [link to relevant documentation]. Figure 1 Step S105 of the illustrated embodiment will not be described again here.
[0069] The permanent magnet synchronous motor control method provided in this invention uses only motor parameters as intermediate quantities for auxiliary prediction during the calculation of predicted current and predicted torque, thereby reducing the dependence on motor parameters and avoiding the transmission, accumulation and amplification of motor parameter errors in the entire control loop, thereby improving the torque control accuracy of the electric drive system.
[0070] This embodiment provides a control method for a permanent magnet synchronous motor. Figure 4 This is a schematic diagram of the fourth process of the permanent magnet synchronous motor control method according to an embodiment of the present invention, as shown below. Figure 4 As shown, the process includes the following steps: Step S401: Determine the reference voltage of the target motor based on its reference torque and current. For details, please refer to [link to relevant documentation]. Figure 1 Step S101 of the illustrated embodiment will not be described again here.
[0071] Step S402: Based on the phase information of the reference voltage of the target motor, determine the voltage vector combination of the reference voltage. For details, please refer to [link to relevant documentation]. Figure 1 Step S102 of the illustrated embodiment will not be described again here.
[0072] Step S403: Based on the current vector combination of the target motor's current and voltage, determine the predicted current and predicted torque of the target motor. For details, please refer to [link to relevant documentation]. Figure 1 Step S103 of the illustrated embodiment will not be described again here.
[0073] Step S404: Construct the objective function based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor.
[0074] In this embodiment of the invention, a first sub-function is constructed based on the difference between the reference torque and the predicted torque. The first sub-function is used to ensure torque tracking accuracy. A second sub-function is constructed based on the sum of squares of each predicted current component in the predicted current. The second sub-function is used to suppress the stator current amplitude and achieve maximum current-to-torque ratio control. A third sub-function is constructed based on the sum of squares of each modulation duty cycle component in the modulation duty cycle. The third sub-function is used to avoid the inverter's switching losses from surging due to extreme duty cycle values. The first, second, and third sub-functions are weighted to obtain the objective function. The objective function can be specifically represented by the following formula (11): Formula (11) in, Let be the objective function. The weights corresponding to the first sub-function. The weights corresponding to the second sub-function. The weights are for the third sub-function.
[0075] In one alternative implementation, the weights of the first, second, and third sub-functions can be adjusted according to actual application requirements. For example, during the startup phase of the target motor, the weight of the first sub-function can be increased to prioritize response speed; during the steady-state phase of the target motor, the weight of the second sub-function can be increased to prioritize energy saving; and the weight of the third sub-function can be kept fixed or slightly adjusted as needed.
[0076] Step S405: Solve the objective function to obtain the target modulation duty cycle of the target motor, and control the operation of the target motor based on the target modulation duty cycle.
[0077] Specifically, step S405 includes: Step S4051: Based on the voltage vector combination and the reference voltage, construct the constraint conditions for the modulation duty cycle.
[0078] In this embodiment of the invention, the modulation duty cycle constraint is constructed based on the sum of the products of each voltage vector in the voltage vector combination and the corresponding modulation duty cycle, and the product of the reference voltage and the sampling period. Specifically, it can be shown in the following formula (12). Thus, the voltage of the target motor is constrained by the modulation duty cycle constraint so that the solution of the objective function can simultaneously satisfy the minimum value of the objective function and the matching of the voltage and torque of the target motor, thereby ensuring effective torque tracking.
[0079] Formula (12) Step S4052: Based on the constraint of modulation duty cycle, with the objective function value being minimized, the objective function is solved to obtain the target modulation duty cycle.
[0080] In this embodiment of the invention, based on the constraint of modulation duty cycle, the objective function is solved with the goal of minimizing its value, and the target modulation duty cycle of the first voltage vector and the second voltage vector are obtained. At the same time, the sum of the modulation duty cycle of the first voltage vector, the modulation duty cycle of the second voltage vector, and the modulation duty cycle of the third voltage vector is 1. Based on the target modulation duty cycle of the first voltage vector and the target modulation duty cycle of the second voltage vector, the target modulation duty cycle of the third voltage vector is calculated.
[0081] In one optional implementation, based on the product of the target modulation duty cycle of each voltage vector and the sampling period, the total operating time of each voltage vector within one sampling period is calculated. Then, combined with the specific modulation method and the switching state corresponding to each voltage vector, a switching signal sequence of the inverter is generated, thereby controlling the switching of the inverter according to the switching signal sequence within each sampling period.
[0082] In one optional implementation, the operation of the target motor can be controlled by a five-segment modulation, that is, the action sequence of each voltage vector is allocated according to the modulation method of first voltage vector → second voltage vector → third voltage vector → second voltage vector → first voltage vector, wherein the action time of each voltage vector is the total action time of the voltage vector within one sampling period.
[0083] In one optional implementation, a seven-segment modulation control of the target motor can be used, that is, the action sequence of each voltage vector is allocated according to the modulation method of third voltage vector → first voltage vector → second voltage vector → third voltage vector → second voltage vector → first voltage vector → third voltage vector, wherein the action time of each voltage vector is equal to half of the total action time of the voltage vector in one sampling period.
[0084] The permanent magnet synchronous motor control method provided in this invention uses predicted torque and predicted current to construct an objective function, thereby achieving advance prediction of the optimal operating point of the current, thus shortening the energy efficiency optimization recovery time of the electric drive system when the load changes suddenly, and improving the response capability of the electric drive system; at the same time, the constructed objective function can be used to accurately lock the optimal operating point of the current, thereby improving the robustness of the electric drive system.
[0085] This embodiment also provides a permanent magnet synchronous motor control device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.
[0086] This embodiment provides a permanent magnet synchronous motor control device, such as... Figure 5 As shown, it includes: The reference voltage determination module 501 is used to determine the reference voltage of the target motor based on the reference torque and current of the target motor. The voltage vector determination module 502 is used to determine the voltage vector combination of the reference voltage based on the phase information of the reference voltage of the target motor. The motor parameter prediction module 503 is used to determine the predicted current and predicted torque of the target motor based on the current current and voltage vector combination of the target motor. The objective function construction module 504 is used to construct an objective function based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor. The objective function solving module 505 is used to solve the objective function, obtain the target modulation duty cycle of the target motor, and control the operation of the target motor based on the target modulation duty cycle.
[0087] In one alternative implementation, the reference voltage determination module 501 includes: The torque equation construction unit is used to construct the torque equation between the reference current and the reference torque of the target motor. The reference current determination unit is used to solve the torque equation with the goal of minimizing the square of the current magnitude of the target motor, and obtain the reference current of the target motor. The reference voltage determination unit is used to determine the reference voltage of the target motor based on the current current and the reference current of the target motor.
[0088] In one optional implementation, the voltage vector combination includes a first voltage vector, a second voltage vector, and a third voltage vector, and the voltage vector determination module 502 includes: The sector determination unit is used to determine the sector where the reference voltage is located based on the phase information of the reference voltage. The first vector determination unit is used to take the adjacent effective vectors corresponding to the sector where the reference voltage is located as the first voltage vector and the second voltage vector of the reference voltage, respectively. The second vector determination unit is used to use the zero vector as the reference voltage for the third voltage vector.
[0089] In one optional implementation, the motor parameter prediction module 503 includes: The first current calculation unit is used to calculate the predicted current corresponding to each voltage vector based on the current current of the target motor and each voltage vector in the voltage vector combination. The second current calculation unit is used to determine the predicted current of the target motor based on the modulation duty cycle and predicted current corresponding to each voltage vector in the voltage vector combination. The predicted torque calculation unit is used to determine the predicted torque of the target motor based on the predicted current of the target motor.
[0090] In one alternative implementation, the objective function construction module 504 includes: The first function construction unit is used to construct the first sub-function based on the difference between the reference torque and the predicted torque; The second function construction unit is used to construct the second sub-function based on the sum of squares of each predicted current component in the predicted current; The third function construction unit is used to construct the third sub-function based on the sum of the squares of the modulation duty cycle components. The objective function construction unit is used to weight the first sub-function, the second sub-function, and the third sub-function to obtain the objective function.
[0091] In one optional implementation, the objective function solving module 505 includes: The constraint construction unit is used to construct the constraint conditions for the modulation duty cycle based on the voltage vector combination and the reference voltage. The objective function solving unit is used to solve the objective function based on the constraint of modulation duty cycle, with the goal of minimizing the value of the objective function, and obtain the target modulation duty cycle.
[0092] In one alternative implementation, the constraint construction unit is used for: The constraints on the modulation duty cycle are constructed based on the sum of the products of each voltage vector in the voltage vector combination and the corresponding modulation duty cycle, as well as the product of the reference voltage and the sampling period.
[0093] The permanent magnet synchronous motor control device provided in this embodiment of the invention can execute the permanent magnet synchronous motor control method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.
[0094] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.
[0095] The following is a detailed reference. Figure 6This diagram illustrates a suitable structural design for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 601, which can perform various appropriate actions and processes based on a program stored in read-only memory (ROM) 602 or a program loaded from memory 608 into random access memory (RAM) 603. RAM 603 also stores various programs and data required for the operation of the electronic device. The processor 601, ROM 602, and RAM 603 are interconnected via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.
[0096] Typically, the following devices can be connected to I / O interface 605: input devices 606 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 607 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 608 including, for example, magnetic tapes, hard disks, etc.; and communication devices 609. Communication device 609 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 6 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.
[0097] In particular, according to embodiments of the present invention, the processes described above with reference to the flowchart can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowchart. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 609, or installed from a memory 608, or installed from a ROM 602. When the computer program is executed by the processor 601, it performs the functions defined in the permanent magnet synchronous motor control method of the embodiments of the present invention.
[0098] Figure 6 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.
[0099] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the permanent magnet synchronous motor control method shown in the above embodiments is implemented.
[0100] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.
[0101] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system, or other device. Furthermore, the embodiments of this invention are not directed to any particular programming language.
[0102] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. Similarly, for the sake of brevity and to aid in understanding one or more aspects of the invention, in the description of exemplary embodiments of the invention above, various features of the embodiments are sometimes grouped together in a single embodiment, figure, or description thereof. The claims, which follow the detailed description, are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.
[0103] Those skilled in the art will understand that the modules in the device of the embodiment can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiment can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components, except that at least some of such features and / or processes or units are mutually exclusive.
[0104] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be construed as limiting the order of execution.
Claims
1. A control method for a permanent magnet synchronous motor, characterized in that, The method includes: The reference voltage of the target motor is determined based on the reference torque and current of the target motor. Based on the phase information of the reference voltage of the target motor, determine the voltage vector combination of the reference voltage; Based on the current current of the target motor and the voltage vector combination, the predicted current and predicted torque of the target motor are determined; Based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor, an objective function is constructed. The objective function is solved to obtain the target modulation duty cycle of the target motor, and the operation of the target motor is controlled based on the target modulation duty cycle.
2. The method according to claim 1, characterized in that, Determining the reference voltage of the target motor based on its reference torque and current includes: Construct the torque equation between the reference current and the reference torque of the target motor; With the goal of minimizing the square of the current magnitude of the target motor, the torque equation is solved to obtain the reference current of the target motor; The reference voltage of the target motor is determined based on the current current and reference current of the target motor.
3. The method according to claim 1, characterized in that, The voltage vector combination includes a first voltage vector, a second voltage vector, and a third voltage vector. Determining the voltage vector combination of the reference voltage based on the phase information of the reference voltage of the target motor includes: Based on the phase information of the reference voltage, the sector in which the reference voltage is located is determined; The adjacent effective vectors corresponding to the sector where the reference voltage is located are respectively used as the first voltage vector and the second voltage vector of the reference voltage; The zero vector is used as the third voltage vector of the reference voltage.
4. The method according to claim 1, characterized in that, The step of determining the predicted current and predicted torque of the target motor based on the current current and the voltage vector combination of the target motor includes: Based on the current current of the target motor and each voltage vector in the voltage vector combination, calculate the predicted current corresponding to each voltage vector; Based on the modulation duty cycle and predicted current corresponding to each voltage vector in the voltage vector combination, the predicted current of the target motor is determined; Based on the predicted current of the target motor, the predicted torque of the target motor is determined.
5. The method according to claim 1, characterized in that, The objective function is constructed based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor, including: Based on the difference between the reference torque and the predicted torque, a first sub-function is constructed; Based on the sum of squares of each predicted current component in the predicted current, a second sub-function is constructed; A third sub-function is constructed based on the sum of squares of the modulation duty cycle components. The first sub-function, the second sub-function, and the third sub-function are weighted to obtain the target function.
6. The method according to claim 1, characterized in that, Solving the objective function to obtain the target modulation duty cycle of the target motor includes: Based on the voltage vector combination and the reference voltage, the constraint conditions for the modulation duty cycle are constructed; Based on the constraint of the modulation duty cycle, the objective function is solved with the goal of minimizing its value to obtain the target modulation duty cycle.
7. The method according to claim 6, characterized in that, The constraint condition for constructing the modulation duty cycle based on the voltage vector combination and the reference voltage includes: Based on the sum of the products of each voltage vector in the voltage vector combination and its corresponding modulation duty cycle, and the product of the reference voltage and the sampling period, the constraint condition for the modulation duty cycle is constructed.
8. A control device for a permanent magnet synchronous motor, characterized in that, The device includes: A reference voltage determination module is used to determine the reference voltage of the target motor based on the reference torque and current current of the target motor. A voltage vector determination module is used to determine the voltage vector combination of the reference voltage based on the phase information of the reference voltage of the target motor; The motor parameter prediction module is used to determine the predicted current and predicted torque of the target motor based on the current current of the target motor and the voltage vector combination. The objective function construction module is used to construct an objective function based on the predicted current, predicted torque, reference torque, and modulation duty cycle of the target motor. The objective function solving module is used to solve the objective function to obtain the target modulation duty cycle of the target motor, and control the operation of the target motor based on the target modulation duty cycle.
9. An electronic device, characterized in that, include: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction that causes the processor to perform the operation of the permanent magnet synchronous motor control method as described in any one of claims 1-7.
10. A computer-readable storage medium, characterized in that, The storage medium stores at least one executable instruction, which, when executed on a permanent magnet synchronous motor control device or electronic device, causes the permanent magnet synchronous motor control device or electronic device to perform the operation of the permanent magnet synchronous motor control method as described in any one of claims 1-7.