Dual-winding reconfigurable permanent magnet synchronous motor smooth switching control method and device

Abstract

This invention discloses a smooth switching control method and device for a dual-winding reconfigurable permanent magnet synchronous motor, relating to the field of motor control technology. The invention effectively divides the dual-winding reconfigurable permanent magnet synchronous motor into multiple unit motors, converting the system current loop controlled variable into unit motor currents through variable gain. When the motor winding state switches, the PWM duty cycle signal is controlled by adjusting the variable gain: when the winding state switches from parallel to series, the terminal voltage of the original motor after the switch is increased to n times that in parallel; when the winding state switches from series to parallel, the terminal voltage of the original motor after the switch is reduced to 1 / n of that in series. This control process strictly maintains the direct and quadrature axis currents of the unit motors before and after the switching when the windings switch between series and parallel, thereby keeping the total output torque of the original motor constant, completely eliminating system speed fluctuations, and achieving smooth and seamless switching of the dual-winding reconfigurable permanent magnet synchronous motor.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a smooth switching control method, device, equipment and medium for a dual-winding reconfigurable permanent magnet synchronous motor. Background Technology

[0002] A dual-winding reconfigurable permanent magnet synchronous motor (PMSM) refers to a PSM whose stator consists of two sets of windings with identical phases and turns. The series-parallel topology switching of these windings can be achieved through electronic switching devices. Through its reconfigurable winding design, the motor can flexibly adjust its operating mode under different conditions. In low-speed, high-torque scenarios, a series mode is used to improve flux linkage utilization and increase the motor's maximum torque. In high-speed, high-efficiency operating scenarios, switching to a parallel mode reduces back electromotive force, significantly expanding the motor's speed range. Furthermore, the dual-winding design possesses excellent fault tolerance. When one winding fails, the faulty winding can be quickly isolated via an electronic switch, and the system can switch to a single-winding operating mode, ensuring continuous operation under derating conditions. Simultaneously, software control enables efficiency-optimized operation, thereby improving the motor's overall efficiency. With its flexible operating modes, excellent speed regulation capabilities, and superior fault tolerance, the dual-winding reconfigurable PSM demonstrates significant application potential in fields such as new energy vehicles and low-altitude aircraft, and is receiving widespread attention and in-depth research.

[0003] However, due to the sudden change in motor parameters caused by the reshaping process of the motor windings, the speed of the motor windings fluctuates drastically during the reshaping process. Scholars at home and abroad have conducted extensive research on smooth switching of multiple windings. At present, variable parameter PI control, sliding film variable structure controller and fuzzy adaptive control strategy are used in dual-winding permanent magnet motors to improve the dynamic response capability of the motor and effectively reduce the torque and speed fluctuation amplitude generated during the winding reshaping process.

[0004] Although the above methods reduce fluctuations to some extent, these control strategies usually take the overall motor current as the control object. Due to the sudden change in the overall parameters of the motor (such as resistance and inductance) caused by winding switching, the control target of the overall current changes significantly under the same output torque. The controller response speed and internal control algorithm are difficult to follow this parameter change, resulting in significant speed and torque fluctuations in the system during the switching process, making it difficult to achieve smooth switching of dual-winding reconfigurable permanent magnet synchronous motors. Summary of the Invention

[0005] This invention provides a smooth switching control method and apparatus for a dual-winding reconfigurable permanent magnet synchronous motor. This method addresses the problem in the prior art where current control strategies typically focus on the overall motor current. Due to the abrupt changes in overall motor parameters caused by winding switching, the control target for the overall current changes significantly under the same output torque. The controller's response speed and internal control algorithm struggle to keep up with these parameter changes, leading to significant speed and torque fluctuations during switching, making it difficult to achieve smooth switching of the dual-winding reconfigurable permanent magnet synchronous motor.

[0006] This invention provides a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor, comprising the following steps: The dual-winding reconfigurable permanent magnet synchronous motor is divided into multiple unit motors, and the three-phase windings of each unit motor are composed of one branch winding from each phase winding of the original motor. Using the current of the unit motor as the controlled variable, the three-phase current of the unit motor is collected and converted into AC and DC axis currents; A variable gain is set in the PWM duty cycle signal of the space vector pulse width modulation (SVPWM) in the control system of a dual-winding reconfigurable permanent magnet synchronous motor. By adjusting the variable gain control PWM duty cycle signal, when the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from parallel to series, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after the switch is increased to n times that in parallel, so as to keep the direct and quadrature axis currents of the unit motor unchanged before and after the winding switch; when the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from series to parallel, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after the switch is reduced to 1 / n of that in series, so as to keep the direct and quadrature axis currents of the unit motor unchanged before and after the winding switch; where n represents the number of parallel branches of the original motor windings.

[0007] Preferably, the step of adjusting the variable gain to control the PWM duty cycle signal to keep the direct and quadrature axis currents of the unit motor constant before and after winding switching includes: A variable gain is set in the PWM duty cycle signal of the space vector pulse width modulation (SVPWM) in the control system of a dual-winding reconfigurable permanent magnet synchronous motor. V g ( s The variable gain V g ( s ) is represented as: ; in: s This indicates the winding state; s=1 indicates the windings are connected in series, and s=0 indicates the windings are connected in parallel. n Indicates the number of parallel branches of the original motor winding; When the winding state of the dual-winding reconfigurable permanent magnet synchronous motor is switched from parallel to series, the variable gain control PWM duty cycle signal is adjusted to be n times that in parallel. After the switch, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor is increased to n times that in parallel, so as to keep the AC and DC axis currents of the unit motor unchanged before and after the winding switch. When the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from series to parallel, the variable gain control PWM duty cycle signal is adjusted to become 1 / n of the series state. After the switch, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor decreases to 1 / n of the series state, which is expressed as: This is to keep the AC and DC axis currents of the unit motor constant before and after the winding switching.

[0008] Preferably, when the in-phase windings of n unit motors are connected in parallel, the number of parallel branches of the original dual-winding permanent magnet synchronous motor windings is n. At this time, the end voltage of each unit motor is the same as the end voltage of the original dual-winding permanent magnet synchronous motor, and the current in the original dual-winding permanent magnet synchronous motor is the sum of the currents of all n in-phase windings of the unit motors. When the number of parallel branches of the original dual-winding permanent magnet synchronous motor is 1, the windings of the same phase in the n unit motors are connected in series. At this time, the current in each unit motor is the same as the current in the original dual-winding permanent magnet synchronous motor, and the terminal voltage of the original dual-winding permanent magnet synchronous motor is the sum of the voltages of the windings of the same phase in the n unit motors.

[0009] Preferably, the sum of the torques of the multiple unit motors is the total electromagnetic torque of the original motor; The resistance, inductance, and back EMF parameters of the unit motor remain unchanged during the winding switching process.

[0010] This invention also provides a smooth switching control device for a dual-winding reconfigurable permanent magnet synchronous motor, comprising: The partitioning module is used to divide the dual-winding reconfigurable permanent magnet synchronous motor into multiple unit motors. The three-phase windings of each unit motor are composed of one branch winding from each phase winding of the original motor. The control module is used to collect the three-phase current of the unit motor with the current of the unit motor as the controlled variable, and convert the three-phase current into AC and DC axis current. A variable gain is set in the PWM duty cycle signal of the space vector pulse width modulation (SVPWM) in the control system of a dual-winding reconfigurable permanent magnet synchronous motor. By adjusting the variable gain control PWM duty cycle signal, when the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from parallel to series, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after the switch is increased to n times that in parallel, so as to keep the direct and quadrature axis currents of the unit motor unchanged before and after the winding switch; when the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from series to parallel, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after the switch is reduced to 1 / n of that in series, so as to keep the direct and quadrature axis currents of the unit motor unchanged before and after the winding switch; where n represents the number of parallel branches of the original motor windings.

[0011] This invention also provides an electronic device, including a memory and a processor; The memory is used to store computer programs; When the processor executes the computer program stored in the memory, it implements the steps of the smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor as described above.

[0012] This invention also provides a computer-readable storage medium for storing a computer program, which, when executed by a processor, implements the steps of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor as described above.

[0013] This invention provides a smooth switching control method and apparatus for a dual-winding reconfigurable permanent magnet synchronous motor, which has the following advantages compared with the prior art: This invention divides a dual-winding reconfigurable permanent magnet synchronous motor into multiple unit motors, making each unit motor an electrically independent controllable object. The controlled variable of the system current loop is converted into the unit motor current, which is then used as the controlled variable. A variable gain is set in the PWM duty cycle signal of the space vector pulse width modulation (SVPWM) of the dual-winding reconfigurable permanent magnet synchronous motor control system. When the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches, the variable gain controls the PWM duty cycle signal. This is achieved when the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from parallel to parallel. When connected in series, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after switching is increased to n times that when connected in parallel. When the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from series to parallel, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after switching is reduced to 1 / n of that when connected in series. This control process keeps the direct and quadrature axis currents of the unit motor unchanged before and after the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches between series and parallel, thus keeping the torque output of the original motor unchanged, thereby eliminating the speed fluctuation of the system and achieving smooth switching of the dual-winding reconfigurable permanent magnet synchronous motor. Attached Figure Description

[0014] Figure 1This is a control block diagram of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor provided in an embodiment of the present invention; Figure 2 A schematic diagram of the overall waveform of the unit motor constant current control strategy (UMCCS) in a steady-state switching experiment of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor provided in an embodiment of the present invention. Figure 3 A partially enlarged schematic diagram of the transition from series mode to parallel mode of the unit motor constant current control strategy (UMCCS) in a steady-state switching experiment of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor provided in an embodiment of the present invention. Figure 4 A partially enlarged schematic diagram of the transition from parallel mode to series mode of the unit motor constant current control strategy (UMCCS) in a steady-state switching experiment of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of the overall waveform of the conventional Overall Motor Current Control Strategy (OMCCS) in a steady-state switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with embodiments of the present invention. Figure 6 This is a partially enlarged schematic diagram showing the transition from series mode to parallel mode of the conventional Overall Motor Current Control Strategy (OMCCS) in a steady-state switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with embodiments of the present invention. Figure 7 This is a partially enlarged schematic diagram showing the transition from parallel mode to series mode of the conventional Overall Motor Current Control Strategy (OMCCS) in a steady-state switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with embodiments of the present invention. Figure 8 A schematic diagram of the overall waveform of the constant current control strategy (UMCCS) of a dual-winding reconfigurable permanent magnet synchronous motor under single-phase zero crossing and simultaneous three-phase switching in a speed dynamic switching experiment provided by an embodiment of the present invention. Figure 9 A partially enlarged schematic diagram of the transition from series mode to parallel mode of the unit motor constant current control strategy (UMCCS) under single-phase zero crossing and simultaneous three-phase switching in a speed dynamic switching experiment of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor provided in an embodiment of the present invention; Figure 10 This is a partially enlarged schematic diagram showing the transition of the unit motor constant current control strategy (UMCCS) from parallel mode to series mode in a speed dynamic switching experiment of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor under single-phase zero crossing and simultaneous three-phase switching, as provided in an embodiment of the present invention. Figure 11This is a schematic diagram of the overall waveform of the traditional overall motor current control strategy (OMCCS) under single-phase zero crossing and simultaneous three-phase switching in a speed dynamic switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with the embodiments of the present invention. Figure 12 This is a partially enlarged schematic diagram showing the transition from series mode to parallel mode of the traditional overall motor current control strategy (OMCCS) under single-phase zero crossing and simultaneous three-phase switching in a speed dynamic switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with embodiments of the present invention. Figure 13 This is a partially enlarged schematic diagram showing the transition from parallel mode to series mode of the traditional overall motor current control strategy (OMCCS) under single-phase zero crossing and simultaneous three-phase switching in a speed dynamic switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with embodiments of the present invention. Figure 14 A schematic diagram of the overall waveform of the constant current control strategy (UMCCS) of a dual-winding reconfigurable permanent magnet synchronous motor under single-phase zero crossing and simultaneous three-phase switching in a torque dynamic switching experiment provided by an embodiment of the present invention. Figure 15 This is a partially enlarged schematic diagram showing the transition of the unit motor constant current control strategy (UMCCS) from series mode to parallel mode in a torque dynamic switching experiment of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor under single-phase zero crossing and simultaneous three-phase switching, as provided in an embodiment of the present invention. Figure 16 This is a partially enlarged schematic diagram showing the transition of the unit motor constant current control strategy (UMCCS) from parallel mode to series mode in a torque dynamic switching experiment of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor under single-phase zero crossing and simultaneous three-phase switching, as provided in an embodiment of the present invention. Figure 17 This is a schematic diagram of the overall waveform of the conventional overall motor current control strategy (OMCCS) under single-phase zero crossing and simultaneous three-phase switching in a torque dynamic switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with the embodiments of the present invention. Figure 18 This is a partially enlarged schematic diagram showing the transition from series mode to parallel mode of the traditional overall motor current control strategy (OMCCS) under single-phase zero crossing and simultaneous three-phase switching in a torque dynamic switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with embodiments of the present invention. Figure 19 This is a partially enlarged schematic diagram showing the transition from parallel mode to series mode of the traditional Overall Motor Current Control Strategy (OMCCS) under single-phase zero crossing and simultaneous three-phase switching in a torque dynamic switching experiment of a dual-winding reconfigurable permanent magnet synchronous motor used for comparison with embodiments of the present invention. Detailed Implementation

[0015] In this specification, unless otherwise stated, the relevant terms used are defined as follows: * **This motor / Original motor:** Both refer to a dual-winding reconfigurable permanent magnet synchronous motor (DWR-PMSM), referring to the overall operating state of the motor as observed from the outside, including macroscopic performance indicators such as total current, total voltage, and total output torque. * **Unit motor:** This refers to a motor divided into several subsystems. Each unit motor consists of a branch winding of each phase winding of the original motor and has independent electrical characteristics. The electromagnetic torques of multiple unit motors are superimposed to form the overall output torque of the original motor.

[0016] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0017] See Figure 1 This invention provides a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor. Currently, the following are the main drawbacks in the multi-winding switching process of dual-winding reconfigurable permanent magnet synchronous motors: ① Speed ​​and torque fluctuations: Traditional control strategies take the overall motor current as the control object. Due to the drastic change in the parameters of the overall motor when the motor windings switch, the control target of the overall current will inevitably change significantly under the same output torque. The controller cannot ideally follow the control requirements, which will inevitably lead to significant speed and torque fluctuations in the system during the switching process. Traditional control strategies can improve the system response speed to some extent through this control algorithm, but cannot fundamentally eliminate the above-mentioned speed and torque fluctuations. These fluctuations will affect the stability and performance of the system, and ultimately affect the product experience, limiting the application scenarios of dual-winding motors.

[0018] ② Current surge: During the switching process, due to the sudden change in motor parameters and the inertial effect of the current loop integrator, the current will experience a large surge; this current surge not only affects the operating stability of the motor, but may also damage the motor and controller.

[0019] ③ Long transition time: Traditional control strategies cannot effectively reduce transient response during multi-winding switching, resulting in a long transition period for the motor during switching. The changes in speed and torque are not smooth, affecting the speed range and system efficiency. The long transition time not only affects thermal management, but also reduces the product's response speed and operating accuracy. Especially in high dynamic demand scenarios such as new energy vehicles and drones, it limits the application of dual-winding motors.

[0020] ④ High control complexity: In order to improve the response speed of the controller, more complex control algorithms are often adopted under traditional control strategies, which increases the difficulty of system design and implementation; complex control strategies also increase the computational burden of the system and affect real-time performance.

[0021] To address the problems existing in current control strategies, the control strategy proposed in this invention is as follows: I. Mathematical Model of Motor

[0022] From the perspective of motor design, when a motor can be connected in multiple parallel circuits, the back EMF, resistance, inductance, and various harmonic distributions of the windings in the parallel branches must be completely consistent. Once the motor (hereinafter referred to as the original motor, i.e., the complete motor directly observed from the outside) has the ability to be connected in multiple parallel circuits, the original motor can be divided into multiple unit motors. The three-phase windings of each unit motor are composed of one branch winding from each phase winding of the original motor. The torque vectors generated by multiple unit motors are superimposed to form the electromagnetic torque of the original motor. During the operation of the original motor, regardless of the circuit connection method, the resistance, inductance, back EMF, and harmonic distribution of the unit motor will not change. The torque generated by the unit motor is only related to the current vector and rotor flux vector of that unit motor. This means that changing the external connection method of the original motor only changes the voltage across the windings of the unit motor, and the other properties of the unit motor remain unchanged.

[0023] According to the two-reaction theory, the voltage equation of the stator winding of the unit motor in the dq coordinate system is: .

[0024] in: u d-ato and u q-ato Indicates the AC / DC voltage of the unit motor; i d-ato and i q-ato Indicates the AC / DC current of the unit motor; L d-ato and L q-ato Indicates the AC / DC inductance of the unit motor; R ato Indicates the phase resistance of the unit motor; ψ f-ato This indicates the magnetic flux linkage of the permanent magnet in the unit motor; ω e This represents the electromagnetic angular velocity of the motor (rad / s).

[0025] The electromagnetic torque generated by the unit motor is expressed as: .

[0026] in: T ato This indicates the output torque of the unit motor (N·m); p n This indicates the number of pole pairs of the original motor.

[0027] When the number of parallel branches of the primary motor winding is 1, all unit motors have the same phase winding connected in series. At this time, the current in the unit motor is the same as the current in the primary motor, and the terminal voltage of the motor is equal to the voltage of all... n The sum of the voltages of the in-phase windings of each unit motor; expressed as: .

[0028] .

[0029] in: and These represent the direct-axis and quadrature-axis voltages of the original motor in series configuration, respectively.

[0030] When the number of parallel branches of the original motor winding is n At this time, all the in-phase windings in the unit are connected in parallel. The voltage at the end of the unit motor is the same as the voltage at the end of the original motor, and the current in the original motor is the same as the voltage across all the units. n The sum of the currents in the same phase windings of each unit motor; expressed as: .

[0031] .

[0032] in: and These represent the direct-axis and quadrature-axis voltages of the original motor in parallel operation, respectively.

[0033] The relationship between the phase voltage and phase current of a permanent magnet synchronous motor in the ABC coordinate system and the direct-axis voltage and current in the dq coordinate system is as follows: .

[0034] .

[0035] .

[0036] .

[0037] .

[0038] .

[0039] in: and These represent the voltage vector and current vector in the ABC coordinate system, respectively. and These represent the voltage vector and current vector in the dq coordinate system, respectively. This indicates the electrical angle of the motor.

[0040] The voltage and current relationship between the original motor and the unit motor under the ABC coordinate system can be obtained from the above formula, expressed as: .

[0041] .

[0042] .

[0043] .

[0044] Regardless of the connection type of the original motor, the electromagnetic torque output by the original motor is always the same for all... n The sum of the electromagnetic torques of each unit motor; expressed as: .

[0045] The mechanical equation of its variant permanent magnet motor is expressed as: .

[0046] in: ω m This represents the mechanical angular velocity of the motor (rad / s); J Indicates the moment of inertia (kg·m2); B Indicates the damping coefficient; T L This represents the load torque (N·m).

[0047] For a dual-winding permanent magnet motor control system, to ensure the motor speed remains constant before and after the switch when the load torque is constant, the current in the motor windings must remain constant before and after the switch, thus requiring the voltage at the motor winding terminals to remain constant. To ensure the voltage at the motor winding terminals remains constant before and after the switch, it is necessary to ensure... That is, when the motor switches from a series connection to a parallel connection, the phase voltage of the original motor should instantly drop to its original value. Conversely, the original motor phase voltage should instantly rise to its original value. times.

[0048] II. Specific control strategies.

[0049] Traditional motor vector control algorithms use the original motor (the overall motor) as the controlled object, typically including a speed loop and a current loop. The current loop uses the motor's dq-axis currents id and iq as controlled variables. Therefore, the phase currents iA and iB of the motor are collected from the inverter output for coordinate transformation. This invention refers to the above control strategy as the Overall Motor Current Control Strategy (OMCCS). When the motor windings are reconfigured (taking the series-to-parallel switch as an example), to keep the motor speed constant, the total current after the winding switch must be n times that before the switch to ensure that the current of each winding is consistent with the original. However, the reference value input of the current loop PI controller depends on the accumulation of speed error and is continuous. It cannot instantly follow the step change of the feedback current. The current loop reference value only starts to increase when the speed drops. Therefore, the traditional control strategy cannot eliminate the torque and speed fluctuations caused by the winding switching of a dual-winding reconfigurable permanent magnet synchronous motor.

[0050] To address the aforementioned problems, this invention takes the unchanged internal physical structure of the motor before and after winding switching as its starting point and the unchanged current within the motor windings before and after switching as its control objective. It improves the traditional motor vector control block diagram and proposes a smooth switching control strategy based on "Unit Motor Constant Current Control Strategy" (UMCCS). This strategy aims to eliminate speed and torque fluctuations during motor remodeling. The improved control block diagram is shown below. Figure 1 As shown.

[0051] Unlike traditional field-oriented control strategies, the "smooth switching control strategy for a dual-winding reconfigurable permanent magnet synchronous motor based on constant current control of a unit motor" treats the unit motor as the controlled object and uses the unit motor current as the controlled variable; therefore, the system collects the phase current of the unit motor... i a-ato and i b-ato By performing coordinate transformation, the dq-axis current of the unit motor can be obtained. i d-ato and i q-ato To ensure consistency of the unit motor current before and after winding switching, a variable gain is introduced into the PWM duty cycle signal output by the SVPWM module in the control system. V g ( s The variable gain V g ( s The value of ) must satisfy the following formula: .

[0052] Where: s represents the winding state.

[0053] The value of s is 1 when the windings of a dual-winding reconfigurable permanent magnet synchronous motor are connected in series, and the value of s is 0 when the windings are connected in parallel. Taking the switching of the winding state of a dual-winding reconfigurable permanent magnet synchronous motor from series to parallel as an example, due to the introduction of variable gain... V g ( s At the instant the winding switches, the PWM duty cycle signal becomes 1 / 3 of the series signal. n This causes the original motor phase voltage to drop instantaneously to its original value. ,Right now This ensures that the unit motor current remains unchanged before and after the winding switching, thus keeping the original motor output torque constant and eliminating speed fluctuations in the system. Similarly, this control strategy can also ensure the consistency of the unit motor current when the motor winding state switches from parallel to series.

[0054] 7. Experiment.

[0055] In the actual operation of a dual-winding motor, winding reconfiguration typically includes three switching modes: random three-phase simultaneous switching, single-phase zero-crossing simultaneous three-phase switching, and independent three-phase zero-crossing switching. Experimental verification shows that the 'Unit Motor Constant Current Control Strategy (UMCCS)' proposed in this invention can achieve a smooth switching effect that completely eliminates speed and torque fluctuations in all three switching modes. To keep the description concise and avoid overly redundant experimental diagrams, the waveform displays for the following steady-state and dynamic switching experiments will use the most representative 'single-phase zero-crossing simultaneous three-phase switching' mode as an example for detailed explanation. The control effects of other switching modes are similar, and will not be elaborated further.

[0056] 1. Steady-state switching experiment.

[0057] First, a steady-state switching experiment is conducted, which involves switching the windings when the motor reaches a steady state; the load torque is then set. T L =1.65 N·m, desired rotational speed ω ref = 200 rpm, V g (0) = 0.52. It should be noted that theoretically, when the number of parallel branches of the original motor winding is n = 2, the variable gain in the parallel state should be 0.5. However, in actual physical hardware systems, considering the inverter dead-time effect and the on-state voltage drop of the switching circuit devices, the actual output voltage will be attenuated to some extent. Therefore, in order to ensure strict consistency between the unit motor terminal voltage and current before and after winding switching on the physical test bench, engineering compensation is performed in the actual control. The actual value is set to 0.52; after the motor speed stabilizes at the desired speed, the windings are switched, and during this process, the original motor current is monitored using an oscilloscope. i A Phase A current of unit motor i a-ato motor speed ω and output torque T e Monitoring was conducted; the experimental results were as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown.

[0058] In the comparison of waveforms during steady-state switching, Figure 2 The waveform diagram shows the overall constant current control strategy for the unit motor. Figure 3 This is a magnified view of the transition from series mode to parallel mode under the constant current control strategy for a single motor. Figure 4 This is a magnified view of the transition from parallel mode to series mode under the constant current control strategy for unit motors; Figure 5 This is the overall waveform diagram for comparison under the traditional overall motor current control strategy. Figure 6 This is a magnified view of the transition from series mode to parallel mode under the traditional overall motor current control strategy. Figure 7 This is a magnified view of the transition from parallel mode to series mode under the traditional overall motor current control strategy.

[0059] As can be seen from the comparison charts above, during steady-state switching, the traditional "overall motor current control strategy" exhibits significant current surges and drastic fluctuations in speed and torque at the switching moment. Specifically, when the winding state switches between series and parallel connections, the overall phase current, speed, and torque all experience severe abrupt overshoots, and only slowly approach a new steady-state value after multiple oscillations; among them, the unit motor phase current ( This also caused violent fluctuations.

[0060] In stark contrast, when using the "unit motor constant current control strategy" proposed in this invention for steady-state switching, regardless of the switching direction, the speed and torque before and after the switching point remain constant without fluctuation. Unit motor phase current ( The amplitude of the current remains strictly unchanged before and after the switching and the waveform transition is smooth. The overall phase current of the motor completes a multiple conversion of amplitude at the moment of switching. The entire switching process is smooth and without current impact, which verifies the excellent performance of the control strategy of this invention.

[0061] Experimental results show that when a dual-winding reconfigurable permanent magnet synchronous motor is reconfigured, the use of a 'unit motor constant current control strategy' can effectively eliminate speed and torque fluctuations caused by winding switching, significantly reduce current surges during the switching process, thereby improving the stability of motor operation and enhancing the robustness and response speed of the control system.

[0062] 2. Dynamic speed switching experiment and dynamic torque switching experiment.

[0063] To verify the performance of different control strategies under dynamic operating conditions, speed dynamic switching experiments and torque dynamic switching experiments were designed to evaluate the stability and responsiveness of the "unit motor constant current control strategy" and the "overall motor current control strategy" in response to speed and torque changes during winding switching in the dynamic operation of the motor. In order to avoid frequent switching of motor winding states, this invention sets a buffer zone during the speed and load torque changes, that is, the switching point speed or torque value is different during the rising process and the falling process, so as to reduce the impact of frequent switching on the system.

[0064] ① Dynamic speed switching experiment.

[0065] In the dynamic speed switching experiment, the motor windings were first set to series mode, and the load torque was set. T L =1.65 N·m, desired rotational speed ω ref = 200 rpm; After starting the motor, it accelerates in series mode. When the speed ω>150 rpm, the windings are switched from series mode to parallel mode, and the motor continues to accelerate until the speed reaches the set value. After reaching the desired speed, it steadily decreases through program settings. ω ref This allows the motor speed to decrease smoothly; when the speed ω < 100 rpm, the motor windings are switched back from parallel mode to series mode; during the experiment, the original motor current is monitored using an oscilloscope. i A Phase A current of unit motor Motor speed ω and output torque T e Monitoring was conducted. Experimental results are as follows: Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 As shown.

[0066] To facilitate a direct comparison of the waveform performance under single-phase zero-crossing and simultaneous three-phase switching conditions, Figure 8 The overall waveform under the unit motor constant current control strategy (UMCCS) of the present invention is shown. Figure 9This is a partially enlarged schematic diagram showing the transition of UMCCS from series mode to parallel mode. Figure 10 A partially enlarged schematic diagram of the transition of UMCCS from parallel mode to series mode; Figure 11 The waveform is shown for comparison under the traditional Overall Motor Current Control Strategy (OMCCS). Figure 12 This is a partially enlarged schematic diagram showing the transition of traditional OMCCS from series mode to parallel mode. Figure 13 This is a partially enlarged schematic diagram showing the transition of traditional OMCCS from parallel mode to series mode.

[0067] The performance differences between the two control strategies in the speed dynamic switching experiment are analyzed as follows: Regarding current waveform stability, when employing the UMCCS strategy of this invention, the phase current of the unit motor is... The amplitude remains constant before and after the switching, and the overall motor phase current The multiplier jump is completed smoothly without any obvious fluctuations or oscillations throughout the process; however, when using the traditional OMCCS strategy, both the overall motor phase current and the unit motor phase current exhibit violent amplitude oscillations at the moment of switching, showing a huge current surge.

[0068] Regarding the smoothness of speed and torque curves, when using the UMCCS strategy of this invention, the speed and torque waveforms maintain a smooth rise and fall throughout the entire dynamic switching process, with no significant change in the waveform slope before and after the switching point, achieving a seamless and smooth transition. In contrast, the traditional OMCCS strategy causes a sudden increase in torque at the switching point during the speed rise process (series to parallel), resulting in a fluctuating acceleration in speed; and a sudden drop in torque at the switching point during the speed fall process (parallel to series), resulting in an accelerated drop in speed.

[0069] ② Torque dynamic switching experiment.

[0070] In the torque dynamic switching experiment, the motor windings were initially set to series mode, and the desired speed was set. Start the motor under no-load conditions. Once the motor stabilizes at the set speed, gradually increase the load torque to... When the load torque reaches At this time, switch the motor windings from series mode to parallel mode; then, steadily reduce the load torque until the torque drops below [a certain value]. Then, the motor winding state was switched back to series mode. Throughout the experiment, an oscilloscope was used to monitor the original motor phase currents. Unit motor A-phase current Motor speed and output torque Real-time monitoring was conducted. Experimental results are as follows: Figures 14 to 19 As shown.

[0071] To facilitate a direct comparison of the waveform performance under single-phase zero-crossing and simultaneous three-phase switching conditions, Figure 14 The overall waveform under the unit motor constant current control strategy (UMCCS) of the present invention is shown. Figure 15 This is a partially enlarged schematic diagram showing the transition of UMCCS from series mode to parallel mode. Figure 16 A partially enlarged schematic diagram of the transition of UMCCS from parallel mode to series mode; Figure 17 The waveform is shown for comparison under the traditional Overall Motor Current Control Strategy (OMCCS). Figure 18 This is a partially enlarged schematic diagram showing the transition of traditional OMCCS from series mode to parallel mode. Figure 19 This is a partially enlarged schematic diagram showing the transition of traditional OMCCS from parallel mode to series mode.

[0072] Comparing the performance of the two control strategies in the torque dynamic switching experiment, it was found that, similar to the speed dynamic switching experiment, under the traditional OMCCS strategy, the current, speed, and torque curves all exhibited severe oscillations near the switching point. Particularly during the first switch from series to parallel, an extremely severe sudden increase in torque occurred, followed by a rapid and significant drop to less than [a certain value] under the control system's action. This could even lead to system misjudgment, causing the motor windings to switch unexpectedly again. In contrast, the UMCCS strategy proposed in this invention has significantly better stability of current, speed and torque during winding switching than traditional control strategies. There are no fluctuations or shocks before and after the entire switching process, and the transition is extremely smooth.

[0073] In summary, this invention addresses the speed and torque fluctuation issues encountered during topology switching in dual-winding reconfigurable permanent magnet synchronous motors by proposing a smooth switching strategy based on Unit Motor Constant Current Control (UMCCS). Unlike traditional control strategies that rely on overall motor current (OMCCS), this invention introduces a variable gain... This control strategy overcomes the adverse effects of sudden changes in motor parameters and the inertia effect of the current loop integrator, strictly ensuring the consistency of the unit motor current before and after winding switching. This control strategy not only fundamentally eliminates speed and torque fluctuations during switching and significantly reduces current surges, but also significantly shortens the transition time. Its simple and efficient control architecture reduces the difficulty of system design and implementation, greatly improving the system's response speed and robustness under dynamic operating conditions, and has extremely high application value in high-dynamic demand fields such as new energy vehicles and low-altitude aircraft.

[0074] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor, characterized in that, Includes the following steps: The dual-winding reconfigurable permanent magnet synchronous motor is divided into multiple unit motors, and the three-phase windings of each unit motor are composed of one branch winding from each phase winding of the original motor. Using the current of the unit motor as the controlled variable, the three-phase current of the unit motor is collected and converted into AC and DC axis currents; A variable gain is set in the PWM duty cycle signal of the space vector pulse width modulation (SVPWM) in the control system of a dual-winding reconfigurable permanent magnet synchronous motor. By adjusting the variable gain control PWM duty cycle signal, when the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from parallel to series, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after the switch is increased to n times that when it is in parallel, so as to keep the AC and DC axis currents of the unit motor unchanged before and after the winding switch. When the winding state of a dual-winding reconfigurable permanent magnet synchronous motor is switched from series to parallel, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after the switch is reduced to 1 / n of that in series, so as to keep the direct and quadrature axis currents of the unit motor unchanged before and after the winding switch; where n represents the number of parallel branches of the original motor winding.

2. The smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor according to claim 1, characterized in that, The method of adjusting the variable gain to control the PWM duty cycle signal to keep the direct and quadrature axis currents of the unit motor constant before and after winding switching includes: A variable gain is set in the PWM duty cycle signal of the space vector pulse width modulation (SVPWM) in the control system of a dual-winding reconfigurable permanent magnet synchronous motor. V g ( s The variable gain V g ( s ) is represented as: ； in: s This indicates the winding state; s=1 indicates the windings are connected in series, and s=0 indicates the windings are connected in parallel. n Indicates the number of parallel branches of the original motor winding; When the winding state of the dual-winding reconfigurable permanent magnet synchronous motor is switched from parallel to series, the variable gain control PWM duty cycle signal is adjusted to be n times that in parallel. After the switch, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor is increased to n times that in parallel, so as to keep the AC and DC axis currents of the unit motor unchanged before and after the winding switch. When the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from series to parallel, the variable gain control PWM duty cycle signal is adjusted to become 1 / n of the series state. After the switch, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor decreases to 1 / n of the series state, which is expressed as: This is to keep the AC and DC axis currents of the unit motor constant before and after the winding switching.

3. The smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor according to claim 2, characterized in that, When n unit motors with the same phase windings are connected in parallel, the number of parallel branches of the original dual-winding permanent magnet synchronous motor windings is n. At this time, the voltage at the end of each unit motor is the same as the voltage at the end of the original dual-winding permanent magnet synchronous motor, and the current in the original dual-winding permanent magnet synchronous motor is the sum of the currents of all n unit motors with the same phase windings. When the number of parallel branches of the original dual-winding permanent magnet synchronous motor is 1, the windings of the same phase in the n unit motors are connected in series. At this time, the current in each unit motor is the same as the current in the original dual-winding permanent magnet synchronous motor, and the terminal voltage of the original dual-winding permanent magnet synchronous motor is the sum of the voltages of the windings of the same phase in the n unit motors.

4. The smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor according to claim 1, characterized in that, The sum of the torques of the multiple unit motors is the total electromagnetic torque of the original motor. The resistance, inductance, and back EMF parameters of the unit motor remain unchanged during the winding switching process.

5. A smooth switching control device for a dual-winding reconfigurable permanent magnet synchronous motor, characterized in that, include: The partitioning module is used to divide the dual-winding reconfigurable permanent magnet synchronous motor into multiple unit motors. The three-phase windings of each unit motor are composed of one branch winding from each phase winding of the original motor. The control module is used to collect the three-phase current of the unit motor with the current of the unit motor as the controlled variable, and convert the three-phase current into AC and DC axis current. A variable gain is set in the PWM duty cycle signal of the space vector pulse width modulation (SVPWM) in the control system of a dual-winding reconfigurable permanent magnet synchronous motor. By adjusting the variable gain control PWM duty cycle signal, when the winding state of the dual-winding reconfigurable permanent magnet synchronous motor switches from parallel to series, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after the switch is increased to n times that when it is in parallel, so as to keep the AC and DC axis currents of the unit motor unchanged before and after the winding switch. When the winding state of a dual-winding reconfigurable permanent magnet synchronous motor is switched from series to parallel, the voltage of the dual-winding reconfigurable permanent magnet synchronous motor after the switch is reduced to 1 / n of that in series, so as to keep the direct and quadrature axis currents of the unit motor unchanged before and after the winding switch; where n represents the number of parallel branches of the original motor winding.

6. An electronic device, characterized in that, include: Memory and processor; The memory is used to store computer programs; When the processor executes the computer program stored in the memory, it implements the steps of the smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, Used to store a computer program, which, when executed by a processor, implements the steps of a smooth switching control method for a dual-winding reconfigurable permanent magnet synchronous motor as described in any one of claims 1 to 4.

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