Motor torque pulsation suppression method and system

Abstract

The invention relates to the technical field of motors, in particular to a motor torque ripple suppression method and system, and the method comprises the steps: determining a conduction starting angle and a turn-off angle of each phase, and constructing an initial reference current waveform under the conditions of no phase overlapping and no forward torque output; inputting the reference current waveform into a motor driving dynamic model and tracking the reference current waveform by a current controller, extracting a magnetizing current for updating a current rising section, and calculating an angle at which a phase current is attenuated to zero at the same time; under the condition that phase overlapping is allowed, the unloading current of the previous phase is corrected and merged into the updated reference current waveform, and the current characteristic of the transition section is formed; and peak identification and angle judgment are further carried out on the reference current in the unloading interval, trimming is carried out according to the actual attenuation characteristic of the phase current, and finally an optimized reference current waveform considering both the dynamic characteristic and the torque stability is obtained. The method can solve the problems that the torque pulsation is large and the reference current is difficult to accurately generate and track in the power generation mode of the switched reluctance motor.

Description

Technical Field

[0001] The present invention relates to the field of motor technology, and in particular to a method and system for suppressing motor torque pulsation. Background Art

[0002] Switched reluctance motors (SRMs) have the advantages of simple structure, low cost, high temperature resistance, and high speed. In recent years, they have been widely used in new energy vehicles, power tools, and wind power generation. In the SRM power generation mode, it uses the change in rotor magnetic resistance to generate an electromotive force, which can be used for braking energy recovery or as an auxiliary power generation device. However, due to the nonlinear electromagnetic characteristics of the SRM and the lack of a constant magnetic field source, the torque output during power generation is prone to large ripple (torque ripple), which seriously affects the stability of the motor system and the output power quality.

[0003] Existing research on SRM torque ripple issues primarily focuses on optimizing motor drive control methods. Common approaches include average torque optimization control, traditional analytical torque split function (TSF) control, direct torque control (DTC), and model predictive control (MPC). Most of these methods target the SRM's motoring mode. In the generating mode, phase current variations are not actively excited and are more significantly affected by load and flux variations, making it difficult for traditional methods to achieve good control results. Furthermore, existing TSF methods often utilize fixed function templates, which fail to fully account for the nonlinear flux characteristics of the motor and make it difficult to generate an optimal current profile adapted to the dynamic characteristics of the generating mode, thus limiting further improvements in torque smoothness. Summary of the Invention

[0004] In view of the above technical problems, the present invention provides a method and system for suppressing motor torque pulsation, aiming to solve the problems of large torque pulsation and difficulty in accurately generating and tracking reference current in the switching reluctance motor power generation mode.

[0005] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by practice of the present disclosure.

[0006] According to one aspect of the present invention, a method for suppressing motor torque pulsation is proposed, the method comprising steps S1-S4: S1: Determine the conduction start angle and turn-off angle of each phase, and generate the initial reference current waveform under the conditions of no phase overlap conduction and no positive torque output; S2: Inputting the obtained reference current waveform into a dynamic model of the motor drive and tracking it by a current controller to obtain a response of the actual phase current, determining the angle at which the phase current rises to the reference current, defining the phase current within the angle as the magnetizing current, using the magnetizing current to update the reference current waveform in the portion between the conduction start angle and the angle, and calculating the zero current angle at which the phase current decays to zero; S3: Based on step S2, phase overlapping conduction is allowed, and the torque required to be provided by the previous phase in the interval from the conduction start angle to the phase current rising to the reference current angle is calculated as the reference torque minus the torque provided by the newly-conducted phase in the interval, and the torque is converted into the current required by the previous phase by looking up the torque-current-angle characteristic table; the obtained curve of the previous phase current is angularly shifted according to the phase offset angle to extend the conduction of the previous phase to the ideal turn-off angle, and the ideal zero current angle of the previous phase is obtained after the phase offset angle; accordingly, the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle is incorporated into the reference current waveform updated in step S2 to obtain the further updated reference current waveform; S4: Based on the reference current waveform obtained in step S3, calculate the peak current and its corresponding angle of the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle; when the zero current angle calculated in step S2 is earlier than the angle corresponding to the peak current, immediately reduce the reference current to zero after the zero current angle; when the zero current angle obtained in step S2 is later than the angle corresponding to the peak current, maintain the reference current at the value of the peak current in the interval from the angle corresponding to the peak current to the zero current angle, and reduce it to zero after the zero current angle, so as to adjust and obtain the final optimized reference current waveform.

[0007] Furthermore, in step S1, the turn-on start angle and the turn-off angle are obtained by iterative optimization calculation of a genetic algorithm. The optimization process aims to maximize the average torque and minimize the torque pulsation. In each iteration, the turn-on start angle and the turn-off angle are adjusted and a corresponding reference current waveform is generated. The waveform is input into the motor dynamic model for simulation to obtain the torque response, and the optimized population is updated according to the torque average value and pulsation evaluation results. When the torque pulsation drops to a preset threshold and the average torque meets the requirements, the optimal turn-on start angle, turn-off angle and corresponding reference current waveform are output.

[0008] Furthermore, in step S2, the reference current waveform obtained in step S1 is used as the dynamic model of the target input motor, and the reference current is tracked and simulated by the current controller to determine the rotation angle corresponding to the actual phase current reaching the reference current value; the phase current at the angle when the phase current reaches the reference value is defined as the magnetizing current, and the portion of the reference current waveform in step S1 within the range from the conduction start angle to the angle is replaced by the magnetizing current to complete the waveform update; and at the same time, the rotation angle corresponding to the actual phase current dropping to zero is obtained as the zero current angle.

[0009] Furthermore, in step S3, phase overlapping conduction is introduced on the basis of the reference current waveform to allow the previous phase to continue to conduct and provide torque after the new phase is conducted; the torque required by the previous phase in the angle interval from the conduction start angle to the actual phase current rising to the reference value is calculated, and its value is equal to the reference torque minus the torque generated by the new conducted phase in the interval; the reference current required by the previous phase is obtained through the torque-current-angle lookup table according to the torque of the previous phase, and the obtained reference current curve of the previous phase is angularly shifted according to the phase offset angle to determine the ideal turn-off angle and the ideal zero current angle of the previous phase, the ideal turn-off angle is equal to the current phase conduction start angle plus the phase offset angle, and the ideal zero current angle is equal to the angle at which the actual phase current rises to the reference value plus the phase offset angle; the reference current segment of the previous phase between the ideal turn-off angle and the ideal zero current angle is incorporated into the reference current waveform updated in step S2 to obtain a reference current waveform including the phase overlapping conduction part.

[0010] Furthermore, in step S4, further optimization is performed on the basis of the reference current waveform, and the peak current and its corresponding angle in the reference current curve of the previous phase in the interval between the ideal turn-off angle and the ideal zero current angle are calculated; when the zero current angle obtained in step S2 occurs before the angle corresponding to the peak current, the reference current is immediately reduced to zero after the zero current angle; when the zero current angle obtained in step S2 lags behind the angle corresponding to the peak current, the reference current is maintained at the value of the peak current between the angle corresponding to the peak current and the zero current angle, and then the reference current is reduced to zero after the zero current angle; the reference current waveform is adjusted to obtain the reference current waveform of the final optimized phase.

[0011] Furthermore, the reference current waveform obtained in step S4 is input as the current command, and hysteresis current control is implemented on the switched reluctance motor power generation mode operating condition to track the reference current waveform, wherein at the beginning of each electrical cycle, a positive DC voltage is applied to the phase winding for initial excitation to establish a magnetic field, and during the power generation stage, the actual phase current is controlled within the hysteresis band above and below the reference current by alternately applying zero voltage and reverse DC voltage at both ends of the phase winding, when the phase current exceeds the upper threshold, a reverse DC voltage is applied to reduce the current, and when the phase current is lower than the lower threshold, a zero voltage is applied to increase the current, so that the actual phase current fluctuates around the reference current waveform, thereby achieving effective tracking and control of the reference current.

[0012] Furthermore, during the hysteresis current control process, when the phase current is within the set hysteresis band threshold range, the phase voltage state of the previous control cycle is maintained to achieve soft switching control, thereby reducing device switching losses and ensuring smooth current transition.

[0013] According to a second aspect of the present disclosure, a motor torque pulsation suppression system is provided, the system comprising: The conduction angle determination module is used to determine the conduction start angle and turn-off angle of each phase, and generate an initial reference current waveform under the conditions of no phase overlap conduction and no positive torque output; a dynamic modeling and tracking module, configured to input the obtained reference current waveform into a dynamic model of the motor drive and track the waveform by a current controller to obtain a response of an actual phase current, determine an angle at which the phase current rises to the reference current, define the phase current within the angle as a magnetizing current, use the magnetizing current to update the reference current waveform in the range from the conduction start angle to the angle, and calculate a zero current angle at which the phase current decays to zero; a phase overlap calculation module, configured to allow phase overlap conduction based on the dynamic modeling and tracking module, calculate the torque required for the previous phase within the interval from the conduction start angle to the phase current rising to the reference current angle as the reference torque minus the torque provided by the newly-conducted phase within the interval, and convert the torque into the current required by the previous phase by looking up a torque-current-angle characteristic table; perform an angular shift on the obtained curve of the previous phase current according to the phase offset angle to extend the conduction of the previous phase to the ideal turn-off angle, and obtain the ideal zero current angle of the previous phase after the phase offset angle; accordingly, incorporate the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle into the reference current waveform updated by the dynamic modeling and tracking module to obtain a further updated reference current waveform; A current waveform optimization module is used to calculate the peak current and its corresponding angle of the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle based on the reference current waveform obtained by the phase overlap calculation module; when the zero current angle calculated by the dynamic modeling and tracking module is earlier than the angle corresponding to the peak current, the reference current is immediately reduced to zero after the zero current angle; when the zero current angle obtained by the dynamic modeling and tracking module is later than the angle corresponding to the peak current, the reference current is maintained at the value of the peak current in the interval from the angle corresponding to the peak current to the zero current angle, and is reduced to zero after the zero current angle, so as to adjust and obtain the final optimized reference current waveform.

[0014] The technical solution disclosed in this disclosure has the following beneficial effects: By constructing a dynamic model of the motor, combining it with a torque-current-angle lookup table, and adopting a four-stage reference current generation and correction strategy, the accuracy and traceability of the current command are effectively improved. This method fully considers the nonlinear magnetic flux characteristics and dynamic response process of the motor in the power generation state, and can significantly reduce torque pulsation, improve the stability of the average torque output and the power generation efficiency of the system. Compared with the existing technology, the present invention avoids the dependence on a fixed current template in the traditional TSF method, has higher flexibility and adaptability, and can be deployed in the existing switched reluctance power generation control system without changing the hardware structure. It has good engineering feasibility and promotion prospects. At the same time, the modular design structure of the present invention also facilitates system integration and function expansion, providing effective technical support for the precise control of SRM under complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart of a method for suppressing motor torque pulsation in an embodiment of this specification; Figure 2 Generate a strategy diagram for the reference current curve in the embodiments of this specification; Figure 3 This is a structural block diagram of a motor torque pulsation suppression system in an embodiment of this specification. DETAILED DESCRIPTION

[0016] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present disclosure will be more comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or that other methods, components, devices, steps, etc. may be employed. In other cases, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0017] The accompanying drawings are merely schematic illustrations of the present disclosure. Identical reference numerals in the drawings denote identical or similar components, and thus their repeated description will be omitted. Some of the blocks shown in the accompanying drawings represent functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0018] The present invention provides a method for suppressing torque pulsation of a product motor. Figure 1 FIG. 1 is a flow chart of a method for suppressing motor torque pulsation according to an embodiment of the present invention. The method can be applied to electronic devices such as personal computers, servers, and controllers. The method can be performed by a device that can be implemented by software and / or hardware. The method can specifically include the following steps S1-S4: In step S1 , the conduction start angle and the turn-off angle of each phase are determined, and an initial reference current waveform is generated under the conditions of no phase overlap conduction and no positive torque output.

[0019] Among them, the turn-on start angle and the turn-off angle are obtained by iterative calculation through genetic algorithm optimization. The optimization process aims to maximize the average torque and minimize the torque pulsation. In each iteration, the turn-on start angle and the turn-off angle are adjusted and the corresponding reference current waveform is generated. The waveform is input into the motor dynamic model for simulation to obtain the torque response, and the optimized population is updated according to the torque average value and pulsation evaluation results. When the torque pulsation drops to a preset threshold and the average torque meets the requirements, the optimal turn-on start angle, turn-off angle and corresponding reference current waveform are output.

[0020] In step S2, the obtained reference current waveform is input into the dynamic model of the motor drive and tracked by the current controller to obtain the response of the actual phase current, determine the angle at which the phase current rises to the reference current, and define the phase current within the angle as the magnetizing current. The magnetizing current is used to update the reference current waveform in the range from the conduction start angle to the angle, and calculate the zero current angle at which the phase current decays to zero.

[0021] Specifically, in step S2, the reference current waveform obtained in step S1 is used as the dynamic model of the target input motor, and the reference current is tracked and simulated by the current controller to determine the rotation angle corresponding to the actual phase current reaching the reference current value; the phase current at the angle when the phase current reaches the reference value is defined as the magnetizing current, and the portion of the reference current waveform in step S1 within the angle range from the conduction start angle to the conduction start angle is replaced by the magnetizing current to complete the waveform update; and at the same time, the rotation angle corresponding to the actual phase current dropping to zero is obtained as the zero current angle.

[0022] In step S3, based on step S2, phase overlapping conduction is allowed, and the torque required to be provided by the previous phase in the interval from the conduction start angle to the phase current rising to the reference current angle is calculated as the reference torque minus the torque provided by the new conduction phase in the interval, and the torque is converted into the current required by the previous phase through a torque-current-angle characteristic lookup table; the obtained curve of the previous phase current is angularly shifted according to the phase offset angle to extend the conduction of the previous phase to the ideal turn-off angle, and the ideal zero current angle of the previous phase is obtained after the phase offset angle; accordingly, the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle is incorporated into the reference current waveform updated in step S2 to obtain a further updated reference current waveform.

[0023] Specifically, in step S3, phase overlapping conduction is introduced on the basis of the reference current waveform to allow the previous phase to continue to conduct and provide torque after the new phase is conducted; the torque required by the previous phase in the angle interval from the conduction start angle to the actual phase current rising to the reference value is calculated, and its value is equal to the reference torque minus the torque generated by the new conduction phase in the interval; the reference current required by the previous phase is obtained through the torque-current-angle lookup table according to the torque of the previous phase, and the obtained reference current curve of the previous phase is angularly shifted according to the phase offset angle to determine the ideal turn-off angle and the ideal zero current angle of the previous phase, the ideal turn-off angle is equal to the current phase conduction start angle plus the phase offset angle, and the ideal zero current angle is equal to the angle at which the actual phase current rises to the reference value plus the phase offset angle; the reference current segment of the previous phase between the ideal turn-off angle and the ideal zero current angle is incorporated into the reference current waveform updated in step S2 to obtain a reference current waveform including the phase overlapping conduction part.

[0024] In step S4, based on the reference current waveform obtained in step S3, the peak current and the corresponding angle of the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle are calculated; when the zero current angle calculated in step S2 is earlier than the angle corresponding to the peak current, the reference current is reduced to zero immediately after the zero current angle; when the zero current angle obtained in step S2 is later than the angle corresponding to the peak current, the reference current is maintained at the value of the peak current in the interval from the angle corresponding to the peak current to the zero current angle, and is reduced to zero after the zero current angle, so as to adjust and obtain the final optimized reference current waveform.

[0025] Among them, in step S4, further optimization is performed on the basis of the reference current waveform, and the peak current and its corresponding angle in the reference current curve of the previous phase in the interval between the ideal turn-off angle and the ideal zero current angle are calculated; when the zero current angle obtained in step S2 occurs before the angle corresponding to the peak current, the reference current is immediately reduced to zero after the zero current angle; when the zero current angle obtained in step S2 lags behind the angle corresponding to the peak current, the reference current is maintained at the value of the peak current between the angle corresponding to the peak current and the zero current angle, and then the reference current is reduced to zero after the zero current angle; the reference current waveform is adjusted to obtain the reference current waveform of the final optimized phase.

[0026] In summary, steps S1-S4 above are summarized as inputting the motor operating speed and reference torque, optimizing the conduction start angle and turn-off angle through a genetic algorithm, and then executing a four-step method: 1. Generate an initial reference current based on the initial conduction angle; 2. Run the motor dynamic model to calculate the magnetizing current and correct the reference current; 3. Consider phase overlap and generate a current waveform including the unloading current; 4. Further optimize based on the peak current angle to obtain the final reference current. Finally, determine whether the optimization goal is met. If not, return to the optimization step and continue iteration. If so, output the optimal conduction angle and reference current waveform, completing the process.

[0027] The four-step process of generating reference current is as follows Figure 2 As shown, where: Step 1: Use the conduction start angle and turn-off angle defined in the optimization phase. In the first step, positive torque output and phase overlap conduction are not considered. Therefore, within the electrical angle interval [360° − phase offset angle, turn-off angle], the reference torque is provided by a single phase. As shown in Figure 2, the phase offset angle is equal to 360° divided by the number of motor phases. Within this interval, the reference current is generated by a "torque-current-angle" reverse lookup table, with the target reference torque as input and the corresponding current output. In the [conduction start angle, 360° − phase offset angle] interval, the reference current remains unchanged and is assumed to decay to zero immediately after the turn-off angle. Therefore, the reference current waveform is expressed as follows:

[0028] in, is the conduction start angle, is the phase shift angle, is the turn-off angle, is the reference current curve, is the reference torque.

[0029] Step 2: Apply the reference current generated in the first step to the motor dynamic model and track it through the current controller. During this dynamic process, the phase current rises from the conduction start angle and reaches the reference current value at a certain angle, which is defined as the peak angle. The phase current in this interval is the magnetizing current. By introducing the magnetizing current to correct the current expression of the previous interval, the updated reference current waveform of the second step can be obtained. At the same time, the angle at which the phase current decays to zero is calculated. Specifically, the process is expressed as:

[0030] in, is the magnetizing current, is the peak angle.

[0031] Step 3: Based on the results of step 2, introduce the phase overlap conduction mechanism. The torque provided by the newly conducting phase is used to correct the torque required by the previous phase. This in turn infers the current required by the previous phase through a table lookup. Its waveform is then shifted by the phase offset angle to derive the ideal turn-off angle and ideal zero-current angle. Finally, the unloading current is added to the interval between the ideal turn-off angle and the ideal zero-current angle to obtain a further corrected reference current.

[0032] Specifically, in the interval The current entering the phase is 𝐼𝑚𝑎𝑔. Therefore, the torque entering the phase can be calculated from the torque-current-angle lookup table as .exist Within the interval, the torque of the exit phase can be calculated according to the following formula, taking into account that the phase torques add up to reach the given torque reference: ; Therefore, the current required to exit the phase can be calculated by the following formula : ; in, By adding a phase shift angle To calculate, because Generated when exiting the associated interrupt. Figure 2 Shown in Considering the symmetry, the phase current of the exit is The current curve should be the same within the interval. This results in an ideal relative breaking angle for In addition, another ideal angle is calculated, where the phase current reaches zero: , given as This ideal zero current angle may be larger or smaller than the zero current angle obtained in the second step.

[0033] The current reference curve in the third step can be obtained by the following formula:

[0034] The current curve in If the reference current generated in step 3 is can track without error, ideally, torque ripple would be eliminated. However, in During the demagnetization phase, the reference current is calculated based on the torque-current-angle characteristic lookup table without considering the motor's magnetic characteristics. This may not accurately track the current reference, depending on the motor's flux characteristics at the considered operating point. Therefore, it cannot be guaranteed that the torque ripple will drop to zero in the third step. In addition, in the third step, the turn-off angle Depend on The turn-off angle is obtained by adding the phase shift angle to the turn-on angle. However, in order to achieve the required electromagnetic performance in generating mode, the turn-off can be further delayed.

[0035] Step 4: In order to solve the above problems, it is necessary to consider the magnetic characteristics of the motor. Create a current reference curve within the specified range. If the zero current angle obtained in the second step is less than the peak current angle, immediately reduce the current to zero after the zero current angle. Otherwise, maintain the peak current until the zero current angle, then return to zero. The resulting optimized reference current waveform is expressed using different formulas based on the following conditions to ensure that the current dynamics match the magnetic characteristics.

[0036] Specifically, in the fourth step, the peak value of the reference current is Calculated within the interval. This point can be expressed as If the phase current obtained in the second step reaches zero angle Less than , the current will be Then set it to zero directly. Figure 2 The angle at which the current reaches zero is expressed in the fourth step as , the reference current expression is given by the following formula:

[0037] The turn-off angle arbitrarily chosen in the first step is There is no direct relationship, because the torque-current-angle lookup table is used in the third step to calculate the reference current. Therefore, it may appear Greater than In this case, the reference current is The interval is set to , the current is After that, it is zero. The optimizer will converge to Reach Therefore, when Greater than When , the reference current is as follows:

[0038] In the second step, the angle at which the phase is turned on, when the current reaches the reference value, needs to be calculated. Furthermore, the angle at which the phase current decays to zero needs to be calculated to obtain the optimal reference current profile. It is worth noting that these angles do not need to be calculated when the proposed current profile-based control strategy is applied to the SRM drive in motoring mode.

[0039] In another embodiment, the reference current waveform obtained in step S4 is input as the current command, and hysteresis current control is implemented for the switched reluctance motor in the generating mode to track the reference current waveform, wherein a positive DC voltage is applied at the beginning of each electrical cycle to initially excite the phase winding to establish a magnetic field, and during the generating stage, the actual phase current is controlled within the hysteresis band above and below the reference current by alternately applying zero voltage and reverse DC voltage at both ends of the phase winding, when the phase current exceeds the upper threshold, a reverse DC voltage is applied to reduce the current, and when the phase current is lower than the lower threshold, a zero voltage is applied to increase the current, so that the actual phase current fluctuates around the reference current waveform, thereby achieving effective tracking control of the reference current.

[0040] Furthermore, during the hysteresis current control process, when the phase current is within the set hysteresis band threshold range, the phase voltage state of the previous control cycle is maintained to achieve soft switching control, thereby reducing device switching losses and ensuring smooth current transition.

[0041] In generator mode, current is used only for initial excitation because the SRM lacks a magnetomotive force source on the rotor to create an initial magnetic field. When zero voltage is applied, the phase current increases in generator mode. When a negative DC link voltage is applied, the current returns to the source. The logic for current hysteresis control in generator mode is shown below:

[0042] The initial excitation stage is indicated by the symbol *. Indicates the Phase voltage of the phase, is the lower hysteresis band, is the upper hysteresis band.

[0043] Based on the same idea, Figure 3 FIG. 1 is a block diagram of a motor torque pulsation suppression system according to an embodiment of the present invention. The system includes: The conduction angle determination module 201 is used to determine the conduction start angle and the turn-off angle of each phase, and generate an initial reference current waveform under the conditions of no phase overlap conduction and no positive torque output; a dynamic modeling and tracking module 202 configured to input the obtained reference current waveform into a dynamic model of the motor drive and track the waveform by a current controller to obtain a response of the actual phase current, determine an angle at which the phase current rises to the reference current, define the phase current within the angle as a magnetizing current, use the magnetizing current to update the reference current waveform in the range from the conduction start angle to the angle, and calculate a zero current angle at which the phase current decays to zero; The phase overlap calculation module 203 is used to allow phase overlapping conduction based on the dynamic modeling and tracking module 202, calculate the torque required by the previous phase from the conduction start angle to the phase current rising to the reference current angle interval as the reference torque minus the torque provided by the newly-conducted phase in the interval, and convert the torque into the current required by the previous phase through a torque-current-angle characteristic table lookup; perform an angular shift on the obtained curve of the previous phase current according to the phase offset angle to extend the conduction of the previous phase to the ideal turn-off angle, and obtain the ideal zero current angle of the previous phase after the phase offset angle; accordingly, incorporate the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle into the reference current waveform updated by the dynamic modeling and tracking module to obtain a further updated reference current waveform; The current waveform optimization module 204 is used to calculate the peak current and its corresponding angle of the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle based on the reference current waveform obtained by the phase overlap calculation module 203; when the zero current angle calculated by the dynamic modeling and tracking module 202 is earlier than the angle corresponding to the peak current, the reference current is immediately reduced to zero after the zero current angle; when the zero current angle obtained by the dynamic modeling and tracking module 202 is later than the angle corresponding to the peak current, the reference current is maintained at the value of the peak current in the interval from the angle corresponding to the peak current to the zero current angle, and is reduced to zero after the zero current angle, so as to adjust and obtain the final optimized reference current waveform.

[0044] The specific details of the above system have been described in detail in the implementation method part. For undisclosed details, please refer to the implementation method part, and thus will not be repeated here.

[0045] This system effectively improves the accuracy and traceability of current instructions by constructing a dynamic model of the motor, combining it with a torque-current-angle lookup table, and adopting a four-stage reference current generation and correction strategy. This method fully considers the nonlinear magnetic flux characteristics and dynamic response process of the motor in the power generation state, and can significantly reduce torque pulsation, improve the stability of the average torque output and the power generation efficiency of the system. Compared with the existing technology, the present invention avoids the dependence on fixed current templates in traditional TSF methods, has higher flexibility and adaptability, and can be deployed in existing switched reluctance power generation control systems without changing the hardware structure. It has good engineering feasibility and promotion prospects. At the same time, the modular design structure of the present invention also facilitates system integration and function expansion, providing effective technical support for the precise control of SRM under complex working conditions.

[0046] The above figures are merely illustrative of the processes included in the methods according to exemplary embodiments of the present disclosure and are not intended to be limiting. It is readily understood that the processes illustrated in the above figures do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0047] It should be noted that although several modules or units of the system are mentioned in the detailed description above, this division is not mandatory. In fact, according to the exemplary embodiments of the present disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units to be embodied.

[0048] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and embodiments are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the claims.

[0049] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for suppressing motor torque pulsation, characterized in that: The method comprises steps S1-S4: S1: Determine the conduction start angle and turn-off angle of each phase, and generate the initial reference current waveform under the conditions of no phase overlap conduction and no positive torque output; S2: Inputting the obtained reference current waveform into a dynamic model of the motor drive and tracking it by a current controller to obtain a response of the actual phase current, determining the angle at which the phase current rises to the reference current, defining the phase current within the angle as the magnetizing current, using the magnetizing current to update the reference current waveform in the portion between the conduction start angle and the angle, and calculating the zero current angle at which the phase current decays to zero; S3: Based on step S2, phase overlapping conduction is allowed, and the torque required to be provided by the previous phase in the interval from the conduction start angle to the phase current rising to the reference current angle is calculated as the reference torque minus the torque provided by the newly-conducted phase in the interval, and the torque is converted into the current required by the previous phase through a torque-current-angle characteristic table lookup; the obtained curve of the previous phase current is angularly shifted according to the phase offset angle to extend the conduction of the previous phase to the ideal turn-off angle, and the ideal zero current angle of the previous phase is obtained after the phase offset angle; Based on this, the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle is incorporated into the reference current waveform updated in step S2 to obtain the further updated reference current waveform; S4: Based on the reference current waveform obtained in step S3, calculate the peak current and its corresponding angle of the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle; when the zero current angle calculated in step S2 is earlier than the angle corresponding to the peak current, immediately reduce the reference current to zero after the zero current angle; when the zero current angle obtained in step S2 is later than the angle corresponding to the peak current, maintain the reference current at the value of the peak current in the interval from the angle corresponding to the peak current to the zero current angle, and reduce it to zero after the zero current angle, so as to adjust and obtain the final optimized reference current waveform.

2. The motor torque pulsation suppression method according to claim 1, characterized in that: In step S1, the turn-on start angle and the turn-off angle are obtained by iterative calculation through genetic algorithm optimization. The optimization process aims to maximize the average torque and minimize the torque pulsation. In each iteration, the turn-on start angle and the turn-off angle are adjusted and a corresponding reference current waveform is generated. The waveform is input into the motor dynamic model for simulation to obtain the torque response, and the optimized population is updated according to the torque average value and pulsation evaluation results. When the torque pulsation drops to a preset threshold and the average torque meets the requirements, the optimal turn-on start angle, turn-off angle and corresponding reference current waveform are output.

3. The motor torque pulsation suppression method according to claim 1, characterized in that: In step S2, the reference current waveform obtained in step S1 is used as a target input into the dynamic model of the motor, and the reference current is tracked and simulated by a current controller to determine the rotation angle corresponding to the reference current value reached by the actual phase current; The phase current at the angle when the phase current reaches the reference value is defined as the magnetizing current, and the portion of the reference current waveform in step S1 within the angle interval from the conduction start angle to the reference current waveform is replaced with the magnetizing current to complete the waveform update; and the rotation angle corresponding to the actual phase current dropping to zero is obtained as the zero current angle.

4. The motor torque pulsation suppression method according to claim 1, characterized in that: In step S3, phase overlapping conduction is introduced on the basis of the reference current waveform to allow the previous phase to continue to conduct and provide torque after the new phase is conducted; the torque required by the previous phase in the angle interval from the conduction start angle to the actual phase current rising to the reference value is calculated, and its value is equal to the reference torque minus the torque generated by the new conduction phase in the interval; the reference current required by the previous phase is obtained through the torque-current-angle lookup table according to the torque of the previous phase, and the obtained reference current curve of the previous phase is angularly shifted according to the phase offset angle to determine the ideal turn-off angle and the ideal zero current angle of the previous phase, the ideal turn-off angle is equal to the current phase conduction start angle plus the phase offset angle, and the ideal zero current angle is equal to the angle at which the actual phase current rises to the reference value plus the phase offset angle; the reference current segment of the previous phase between the ideal turn-off angle and the ideal zero current angle is incorporated into the reference current waveform updated in step S2 to obtain a reference current waveform including the phase overlapping conduction part.

5. The motor torque pulsation suppression method according to claim 1, characterized in that: In step S4, further optimization is performed based on the reference current waveform to calculate the peak current and its corresponding angle in the reference current curve of the previous phase within the interval between the ideal turn-off angle and the ideal zero current angle; when the zero current angle obtained in step S2 occurs before the angle corresponding to the peak current, the reference current is immediately reduced to zero after the zero current angle; when the zero current angle obtained in step S2 lags behind the angle corresponding to the peak current, the reference current is maintained at the value of the peak current between the angle corresponding to the peak current and the zero current angle, and then the reference current is reduced to zero after the zero current angle; The reference current waveform is adjusted to obtain the reference current waveform of the final optimized phase.

6. The motor torque pulsation suppression method according to claim 1, characterized in that: The reference current waveform obtained in step S4 is input as the current command, and hysteresis current control is implemented for the switched reluctance motor in the generating mode to track the reference current waveform, wherein at the beginning of each electrical cycle, a positive DC voltage is applied to initially excite the phase winding to establish a magnetic field, and during the generating stage, the actual phase current is controlled within the hysteresis band above and below the reference current by alternately applying zero voltage and reverse DC voltage at both ends of the phase winding, when the phase current exceeds the upper threshold, a reverse DC voltage is applied to reduce the current, and when the phase current is lower than the lower threshold, a zero voltage is applied to increase the current, so that the actual phase current fluctuates around the reference current waveform, thereby achieving effective tracking control of the reference current.

7. The motor torque pulsation suppression method according to claim 6, characterized in that: In the hysteresis current control process, when the phase current is within the set hysteresis band threshold range, the phase voltage state of the previous control cycle is maintained to achieve soft switching control, thereby reducing device switching losses and ensuring smooth current transition.

8. A motor torque pulsation suppression system, the system comprising: The conduction angle determination module is used to determine the conduction start angle and turn-off angle of each phase, and generate an initial reference current waveform under the conditions of no phase overlap conduction and no positive torque output; a dynamic modeling and tracking module, configured to input the obtained reference current waveform into a dynamic model of the motor drive and track the waveform by a current controller to obtain a response of an actual phase current, determine an angle at which the phase current rises to the reference current, define the phase current within the angle as a magnetizing current, use the magnetizing current to update the reference current waveform in the range from the conduction start angle to the angle, and calculate a zero current angle at which the phase current decays to zero; a phase overlap calculation module, configured to allow phase overlap conduction based on the dynamic modeling and tracking module, calculate the torque required by the previous phase within the interval from the conduction start angle to the phase current rising to the reference current angle as the reference torque minus the torque provided by the newly-conducted phase within the interval, and convert the torque into the current required by the previous phase by looking up a torque-current-angle characteristic table; perform an angular shift on the obtained curve of the previous phase current according to the phase offset angle to extend the conduction of the previous phase to the ideal turn-off angle, and obtain the ideal zero current angle of the previous phase after the phase offset angle; Based on this, the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle is incorporated into the reference current waveform updated by the dynamic modeling and tracking module to obtain a further updated reference current waveform; A current waveform optimization module is used to calculate the peak current and its corresponding angle of the reference current of the previous phase between the ideal turn-off angle and the ideal zero current angle based on the reference current waveform obtained by the phase overlap calculation module; when the zero current angle calculated by the dynamic modeling and tracking module is earlier than the angle corresponding to the peak current, the reference current is immediately reduced to zero after the zero current angle; when the zero current angle obtained by the dynamic modeling and tracking module is later than the angle corresponding to the peak current, the reference current is maintained at the value of the peak current in the interval from the angle corresponding to the peak current to the zero current angle, and is reduced to zero after the zero current angle, so as to adjust and obtain the final optimized reference current waveform.

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