A multi-mode switching control method for an axial flux double-stator motor

Abstract

The application discloses a kind of axial flux double-stator motor multi-mode switching control methods.Motor motion state and double-stator state are collected, mode determination data is generated;From single-stator energy-saving mode, double-stator collaborative mode, double-stator differentiation mode and fault degradation mode, determine target operating mode and switching type;According to current and target torque distribution state, the switching torque is divided into continuous retention torque and migration torque, and the state preset is executed to the pipe side;Continuous retention torque is maintained, and migration torque is gradually transferred from the release side to the pipe side;According to the transfer rate and torque command of migration torque, the target torque distribution state is formed and verified according to the synthesis torque deviation and tracking error correction;When verification fails, re-determine the mode, isolate the fault side when fault occurs and perform degradation switching by the healthy side.The application can reduce the torque fluctuation and tracking error caused by mode switching, and consider light-load energy saving, dynamic response, precision control and fault tolerance.

Description

Technical Field

[0001] This invention relates to the field of special motor control technology, specifically to a multi-mode switching control method for an axial flux dual-stator motor. Background Technology

[0002] Axial flux motors are characterized by short axial dimensions, high torque density, and compact structure, making them suitable for servo drive equipment with limited installation space and requiring rapid response. Dual-stator axial flux motors improve output capacity by having two stators work together on the rotor assembly, and the operating mode of the two stators can be adjusted according to the load conditions.

[0003] Existing dual-stator motor control typically employs simultaneous operation of both stators or starting and stopping one stator according to a load threshold. When both stators are running continuously, under light load conditions, both windings still need to be energized and driven, increasing copper losses and drive losses. While directly shutting down one stator can reduce energy consumption, when the motion state or load changes, the shut-down stator needs to be reactivated, which can easily lead to combined torque fluctuations due to asynchronous current establishment and sudden changes in torque sharing.

[0004] When switching between operating conditions such as low-speed tracking, high-speed rotation, precision compensation, and fault operation, the target torque distribution relationship between the two stators differs. Existing control methods often directly switch operating modes based on torque, speed, or fault signals, without distinguishing between the torque that maintains its original load distribution before and after the switch and the torque that needs to be changed for the stator. This leads to short-term torque drops, excessive superposition, and increased position tracking errors during stator engagement, disengagement, or dual-sided torque redistribution. Furthermore, the lack of coordination between fault switching and normal mode switching means that after the fault side is isolated, the healthy side may exceed the usable output range due to a sudden increase in torque command, affecting the stable operation of the system.

[0005] Therefore, a multi-mode switching control method for axial flux dual-stator motors is needed to select the appropriate operating mode based on the motion state and the operating state of the dual stators, and to maintain continuous synthetic torque during mode switching, thereby reducing the impact of mode switching on servo control accuracy and operational stability. Summary of the Invention

[0006] This invention provides a multi-mode switching control method for an axial flux dual-stator motor, comprising: S10. Collect the motion state and operating state of the axial flux dual-stator motor and generate mode determination data; S20. Based on the mode determination data, determine the target operating mode from the single stator energy-saving mode, dual stator collaborative mode, dual stator differentiated mode and fault degradation mode, and determine the switching type from the current operating mode to the target operating mode. S30. Based on the torque distribution state corresponding to the current operating mode and the target operating mode, divide the switching torque into continuous holding torque and migration torque that changes the stator bearing the load, and preset the execution state of the takeover side of the migration torque. S40. Maintain continuous holding torque, gradually transfer the transfer torque from the release side to the control side, so that the combined torque of the two stators remains continuous; S50. Based on the synthetic torque deviation and tracking error during mode switching, the transfer process of the migration torque is corrected to form the target torque distribution state. S60. Verify the target torque distribution status. If the verification passes, lock the target operating mode. If the verification fails or a fault occurs, re-execute the mode determination and switching.

[0007] The above-described method for multi-mode switching control of an axial flux dual-stator motor includes a first stator and a second stator arranged axially, and a rotor assembly forming an axial air gap with the first stator and the second stator. The first stator and the second stator are respectively connected to independent drive units.

[0008] The multi-mode switching control method for an axial flux dual-stator motor described above includes acquiring the motion state and dual-stator operating state of the axial flux dual-stator motor, and generating mode determination data, including: S101. Determine the motion stage, target torque, and tracking error based on motion commands, position feedback, and speed feedback; S102. Determine the corresponding available torque and thermal margin based on the current, temperature and driving state of the first stator and the second stator, and form mode determination data.

[0009] The multi-mode switching control method for an axial flux dual-stator motor, as described above, involves determining a target operating mode from single-stator energy-saving mode, dual-stator cooperative mode, dual-stator differentiated mode, and fault degradation mode based on mode determination data, and determining the switching type from the current operating mode to the target operating mode, including: S201. Determine the target operating mode based on the target torque, tracking error, speed change, and the available status of the dual stators; S202. Determine whether to switch to increased or decreased power supply, redistribution, or fault-crossing based on the difference between the current operating mode and the target operating mode.

[0010] The multi-mode switching control method for an axial flux dual-stator motor, as described above, includes dividing the switching torque into continuous holding torque and shifting torque that changes the load on the stator, based on the torque distribution state corresponding to the current operating mode and the target operating mode, and presetting the execution state of the shifting torque on the control side, including: S301. Compare the current torque distribution state with the target torque distribution state to determine the continuous holding torque, the transfer torque, the control side, and the release side. S302. Check the driving status and remaining output of the connecting pipe side, and initialize the current control status of the connecting pipe side according to the rotor angular position.

[0011] The multi-mode switching control method for an axial flux dual-stator motor described above, wherein maintaining continuous holding torque and gradually transferring the migrating torque from the release side to the control side to keep the combined torque of the dual stators continuous, includes: S401, Maintain continuous holding torque and gradually increase the migration torque borne by the control side; S402. Reduce the migration torque borne by the release side based on the migration torque generated on the control side, and correct the torque command on both sides.

[0012] The multi-mode switching control method for an axial flux dual-stator motor described above includes a process for correcting the transfer torque based on the synthetic torque deviation and tracking error during mode switching to form a target torque distribution state, comprising: S501. Adjust the transfer rate of the migrating torque according to the combined torque deviation and tracking error; S502. When the combined torque deviation and tracking error meet the allowable conditions, the transfer of migration torque is completed, and the target torque distribution state is formed.

[0013] The multi-mode switching control method for an axial flux dual-stator motor described above includes verifying the target torque distribution state, locking the target operating mode when the verification passes, and re-executing mode determination and switching when the verification fails or a fault occurs. This includes: S601. Verify the target torque distribution status and lock the target operating mode based on the position response, speed response and dual stator operating status. S602. If the verification fails, the target operating mode is redefined. If a fault occurs, the faulty side is isolated and the healthy side performs a fault degradation switch within the available torque range.

[0014] The beneficial effects achieved by this invention are as follows: Based on the motor's motion state and the dual-stator operating state, this invention switches between single-stator energy-saving mode, dual-stator collaborative mode, dual-stator differentiated mode, and fault degradation mode, adapting to different operating conditions such as light-load tracking, rapid rotation, precision compensation, and fault operation. By dividing the switching torque into continuous holding torque and transfer torque, while maintaining the continuous holding torque, the transfer torque is gradually transferred from the release side to the takeover side, reducing the combined torque fluctuations and position tracking errors caused by stator engagement, disengagement, and torque redistribution. By correcting the transfer process of the transfer torque based on the combined torque deviation and tracking error, and verifying the switching results, the smoothness and reliability of mode switching are improved. In the event of a fault, the faulty side is isolated, and the healthy side performs a degradation switch within the available torque range, thus balancing the requirements of light-load energy saving, dynamic response, precision control, and fault-tolerant operation. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0016] Figure 1 This is a flowchart of a multi-mode switching control method for an axial flux dual-stator motor provided in Embodiment 1 of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 like Figure 1 As shown, Embodiment 1 of this application provides a multi-mode switching control method for an axial flux dual-stator motor, including: S10. Collect the motion state and operating status of the axial flux dual-stator motor and generate mode determination data.

[0019] Specifically, the axial flux dual-stator motor includes a first stator, a second stator, and a rotor assembly. The first and second stators are respectively connected to independent drive units. The controller synchronously acquires motion commands, position feedback, speed feedback, and the current, temperature, and drive status of the two stators to form mode determination data corresponding to the current control cycle, including the following sub-steps: S101. Determine the motion stage, target torque, and tracking error based on motion commands, position feedback, and speed feedback.

[0020] Specifically, the controller receives the target position, target speed, and direction of motion from the servo system, and obtains the actual position of the rotor assembly through the position sensor, determining the actual angular position of the rotor assembly as the rotor angular position. The actual speed is determined based on the actual position at adjacent sampling times, and the motion command, actual position, rotor angular position, and actual speed are aligned according to a unified sampling time.

[0021] The controller determines the position tracking error based on the difference between the target position and the actual position, and the speed tracking error based on the difference between the target speed and the actual speed. It also reads the target torque generated by the servo control loop based on motion commands and feedback data. The target torque represents the combined torque that the first and second stators need to produce together within the current control cycle.

[0022] The current motion stage is determined based on the changes in the target speed, actual speed, and target torque. When the target speed is in the low-speed range and the position tracking error remains stable, it is determined to be the low-speed tracking stage; when the target speed or target torque continues to increase, it is determined to be the acceleration stage; when the target speed or target torque continues to decrease, it is determined to be the deceleration stage; when the changes in both the target speed and target torque are within a stable range, it is determined to be the stable operation stage; when the target speed is zero and the actual position remains within the allowable range of the target position, it is determined to be the stationary holding stage.

[0023] To prevent the motion phase from changing repeatedly in the critical state, the controller sets entry and exit conditions for each motion phase. The motion phase is updated only after the preset confirmation time is met continuously in the corresponding state, and the motion phase, target torque, position tracking error and speed tracking error are recorded.

[0024] S102. Determine the corresponding available torque and thermal margin based on the current, temperature and driving state of the first stator and the second stator, and form mode determination data.

[0025] Specifically, the controller reads the phase current, winding temperature, driver temperature, and drive fault flag of the first and second stators, respectively. Based on the phase current and rotor angular position, it queries the pre-calibrated stator torque characteristics to determine the current output torque of the two stators; based on the allowable current range of the independent drive unit and the corresponding stator torque characteristics, it determines the available torque of the first and second stators.

[0026] The controller determines the remaining temperature rise margin between the winding temperature and the winding protection temperature, and the remaining temperature rise margin between the driver temperature and the driver protection temperature, and determines the smaller of the two remaining temperature rise margins as the thermal margin of the corresponding stator. When the winding temperature or driver temperature reaches the warning condition, the allowable current and available torque of the corresponding stator are reduced according to the degree to which the temperature approaches the protection temperature; when the protection condition is reached, the corresponding stator is marked as unusable.

[0027] When an independent drive unit has no fault indication and the current and temperature of the corresponding stator are within the rated operating range, the stator is determined to be in normal condition; when the temperature reaches the warning condition but still has limited output capability, it is determined to be in a limited load state; when a short circuit, overcurrent, power device failure, or communication interruption fault indication occurs, it is determined to be in a fault state, and the fault type and trigger time are recorded.

[0028] The controller correlates the motion stage, target torque, position tracking error, and speed tracking error determined in S101 with the current output torque, available torque, thermal margin, and status flags of the first and second stators to generate mode determination data for the current control cycle. This mode determination data is updated synchronously with motion feedback and the operating parameters of the two stators.

[0029] S20. Based on the mode determination data, determine the target operating mode from the single stator energy-saving mode, dual stator collaborative mode, dual stator differentiated mode and fault degradation mode, and determine the switching type from the current operating mode to the target operating mode.

[0030] Specifically, the controller reads the mode determination data generated by S10, determines the target operating mode based on the motion stage, target torque, tracking error, and the available torque, thermal margin, and status flags of the first and second stators, and determines the switching type based on the difference between the target operating mode and the current operating mode, including the following sub-steps: S201. Determine the target operating mode based on the target torque, tracking error, speed change, and the availability of the dual stators.

[0031] Specifically, when the motor is in a stationary holding, low-speed tracking, or stable operation phase, the target torque is within the available torque range of any stator, and the position tracking error and speed tracking error remain stable, the controller determines the single stator energy-saving mode and selects the stator with larger thermal margin and normal driving state from the first stator and the second stator to bear the target torque, while the other stator remains in synchronous standby.

[0032] When the motor is in the acceleration or deceleration phase, or when the target torque exceeds the available torque of any single stator, the controller determines the dual-stator cooperative mode. In dual-stator cooperative mode, both the first and second stators bear continuous output torque, and the torque-bearing ratio is determined according to their respective available torque and thermal margin.

[0033] When the motor is in a low-speed tracking or stable operation phase, and the target torque remains within a preset stable range, but the position tracking error, speed tracking error, or actual output torque fluctuates continuously, the controller determines the dual-stator differentiation mode. In the dual-stator differentiation mode, the stator with a larger thermal margin and stable output state is designated as the base side, which bears the base torque; the other normal stator is designated as the compensation side, which bears the compensation torque generated according to the tracking error and output torque fluctuations.

[0034] When the first stator, second stator, or corresponding independent drive unit generates a fault indication, the controller determines the fault degradation mode, isolates the faulty side, and determines the degradation output range based on the available torque on the healthy side. When both stators are in a faulty state, torque output is stopped and a shutdown protection command is generated. When multiple mode conditions are met simultaneously, the target operating mode is determined sequentially according to the fault degradation mode, dual-stator collaborative mode, dual-stator differentiated mode, and single-stator energy-saving mode.

[0035] S202. Determine whether to switch to increased or decreased power supply, redistribution, or fault-crossing based on the difference between the current operating mode and the target operating mode.

[0036] Specifically, the controller reads the current operating mode and the corresponding torque distribution status, and compares it with the target operating mode determined in S201. When the current operating mode is the single stator energy-saving mode and the target operating mode is the dual stator collaborative mode or the dual stator differentiated mode, this switch is determined as an additional switching, and the stator currently in synchronous standby state is determined as the stator to be added.

[0037] When the current operating mode is dual-stator collaborative mode or dual-stator differentiated mode, and the target operating mode is single-stator energy-saving mode, this switch is determined as a reduction switch, and the stator to be retained and the stator to be withdrawn are determined according to the thermal margin, available torque and drive status of the first stator and the second stator.

[0038] When both the first and second stators are running and it is necessary to change the torque sharing ratio on both sides, or when it is necessary to exchange the stators bearing the target torque in single-stator energy-saving mode, this switching is defined as a redistribution switching. The redistribution switching also includes switching between dual-stator cooperative mode and dual-stator differentiated mode, as well as the exchange between the base side and the compensation side in dual-stator differentiated mode.

[0039] When a fault is detected in the first stator, second stator, or corresponding independent drive unit, this switchover is identified as a fault-level skip switchover, and the waiting time for the normal mode confirmation period is canceled. For increase-input switchover, decrease-input switchover, and redistribution switchover, a mode switchover command is generated after the judgment conditions corresponding to the target operating mode are continuously met for a preset confirmation period; if the judgment conditions disappear within the confirmation period, the current operating mode is maintained. The mode switchover command records the current operating mode, the target operating mode, the switchover type, and the current torque distribution status.

[0040] S30. Based on the torque distribution state corresponding to the current operating mode and the target operating mode, the switching torque is divided into continuous holding torque and migration torque that changes the stator bearing the load, and the execution state of the takeover side of the migration torque is preset.

[0041] Specifically, the controller reads the current operating mode, target operating mode, and switching type determined in S20, and determines the current torque load of the first stator and the second stator at the start of the switching, as well as the target torque load in the target operating mode. By comparing the torque load relationship between the two sides, it determines the continuous holding torque, the transfer torque, the takeover side, and the release side, including the following sub-steps: S301. Compare the current torque distribution state with the target torque distribution state to determine the continuous holding torque, the transfer torque, the control side, and the release side.

[0042] Specifically, the controller determines the target torque at the start of mode switching as the switching reference torque, uses the actual output torques of the first and second stators at that moment to form the current torque distribution state, and determines the target torque distribution state of the switching reference torque under the target operating mode based on the target operating mode, the available torque on both sides, and the thermal margin. In single-stator energy-saving mode, the switching reference torque is allocated to the selected operating stator; in dual-stator collaborative mode, the switching reference torque is allocated according to the available torque on both sides and the thermal margin; in dual-stator differentiated mode, the basic torque in the switching reference torque is allocated to the basic side, and the compensation torque is allocated to the compensation side; in fault degradation mode, the switching reference torque is limited to the available torque range of the healthy side.

[0043] For the first and second stators, their current torque load is compared with the target torque load. The portion of the shared torque that the stator maintains load in the same direction before and after the switch is determined as the continuous holding torque; the portion of the current torque load that needs to be reduced from the original load stator and taken over by another corresponding stator is determined as the transfer torque. When the target torque direction is opposite to the current torque direction, no continuous holding torque is set, and the process of reducing the original torque and establishing the target torque is included in the transfer torque. When the target torque changes relative to the switching reference torque during mode switching, the difference between the two is determined as the dynamic compensation torque. The dynamic compensation torque does not change the already determined continuous holding torque and transfer torque, and is distributed according to the remaining output of the first and second stators.

[0044] In the process of adding new stators, the stator to be added is designated as the takeover side, and the side of the currently running stator that bears the torque to be transferred is designated as the release side. In the process of reducing new stators, the stator that remains in operation is designated as the takeover side, and the stator to be withdrawn is designated as the release side. In the process of redistribution switching, the stator with the increased target torque is designated as the takeover side, and the stator with the decreased target torque is designated as the release side.

[0045] In fault-level handover, the torque currently borne by the faulty side and that can be taken over by the healthy side is determined as the transfer torque, the healthy side is determined as the takeover side, and the transfer torque is limited to the remaining output range of the healthy side; the portion exceeding the available torque of the healthy side is not included in the transfer torque, and the total output torque of the target torque distribution state is reduced accordingly.

[0046] S302. Check the driving status and remaining output of the connecting pipe side, and initialize the current control status of the connecting pipe side according to the rotor angular position.

[0047] Specifically, the controller reads the drive fault flag, actual current, winding temperature, and driver temperature on the control side to confirm that there are no protection faults on the control side and that it is within the allowable operating range. It determines the remaining output power based on the difference between the available torque on the control side and the current output torque, and compares the remaining output power with the torque to be transferred. If the remaining output power is insufficient, the transfer amount is limited to the corresponding remaining output power range, and the target torque distribution state is adjusted.

[0048] When the feeder side is in synchronous standby mode, the controller determines the target current control phase based on the rotor angular position, the mounting angular position of the feeder side winding, and the pre-calibrated torque characteristics, keeps the torque current command at zero, and initializes the coordinate transformation angle and current regulator state of the corresponding independent drive unit. When the feeder side is already in operation, it maintains the current current control state and sets the allowable increase range of the migration torque according to the target torque load.

[0049] After the state preset is completed, the controller checks the electrical angle synchronization status, current regulator status, and drive permission status of the takeover side. When all statuses meet the takeover conditions, the takeover side is marked as allowable to takeover; if any status does not meet the takeover conditions, the increase of torque current on the takeover side is prohibited, and the torque is continuously maintained at the current bearing state.

[0050] S40. Maintain continuous holding torque, gradually transfer the transfer torque from the release side to the control side, so that the combined torque of the two stators remains continuous.

[0051] Specifically, the controller reads the continuous holding torque, transfer torque, takeover side, release side, and target torque distribution status determined by S30, maintains the continuous holding torque bearing relationship unchanged, and controls the transfer torque to gradually transfer between the first stator and the second stator, including the following sub-steps: S401, maintain continuous holding torque and gradually increase the migration torque borne by the control side.

[0052] Specifically, the controller generates a holding torque command based on the continuous holding torque and the stator it supports, ensuring that the corresponding stator continues to support the continuous holding torque during mode switching. When the target torque of the stator supporting the continuous holding torque changes, the holding torque command is adjusted within its available torque range to prevent the motion command from ceasing to update during mode switching.

[0053] When the takeover side is marked as allowable for takeover, the controller determines the torque increase rate based on the transfer torque, the remaining output of the takeover side, and the corresponding switching type, and gradually increases the transfer torque borne by the takeover side from zero. During the increase-in switching, the controller controls the synchronous standby stator to establish the transfer torque; during the decrease-in switching, the controller controls the stator that remains in operation to increase the transfer torque; during the redistribution switching, the controller controls the stator with the increased target torque borne to establish the transfer torque.

[0054] The controller queries the corresponding stator torque characteristics based on the actual current and rotor angular position on the receiving side to determine the actual new torque already formed on the receiving side, and identifies the portion used to replace the torque on the release side as the transfer torque receiving amount. When the actual current, winding temperature, or driver temperature on the receiving side approaches the allowable operating boundary, the torque increase rate is reduced; when the protection condition is met, the increase of torque on the receiving side is stopped.

[0055] When the target torque changes during the switching period relative to the start of the switching, the controller determines the torque corresponding to the change as the dynamic compensation torque and distributes it within the remaining output range of the first stator and the second stator, so that the migration torque transfer process is consistent with the real-time motion command.

[0056] S402. Reduce the migration torque borne by the release side based on the migration torque generated on the control side, and correct the torque command on both sides.

[0057] Specifically, based on the migration torque takeover amount determined by S401, the controller reduces the migration torque borne by the release side according to the corresponding takeover amount, so that the increased migration torque on the takeover side corresponds to the decreased migration torque on the release side. The torque reduction on the release side must not exceed the actual new torque already generated on the takeover side. When the takeover side has not yet formed a stable output, the current torque on the release side is maintained.

[0058] In each switching control cycle, the controller summarizes the actual output torques of the first and second stators and compares them with the current target torque. When the combined torque of the two stators is lower than the current target torque, the torque reduction on the release side is reduced, or the torque command on the control side is increased within the remaining output range. When the combined torque of the two stators is higher than the current target torque, the torque increase on the control side is reduced, or the torque reduction on the release side is appropriately increased.

[0059] When the target torque direction is opposite to the torque direction at the start of the switching, the controller first gradually reduces the original torque on the release side to the allowable commutation range, then controls the control side to establish torque along the target direction, and coordinates the original torque reduction rate and the target torque establishment rate according to the torque deviation of the two stators to avoid the two stators forming excessive reverse torque at the same time.

[0060] Once the transfer torque borne by the takeover side reaches the transfer torque requirement for this transfer, the corresponding transfer torque on the release side drops to zero. When the release side still bears the continuous holding torque, it maintains the corresponding torque command; when the release side no longer bears torque under the target torque distribution state, its torque current is gradually reduced to zero and it remains in synchronous standby.

[0061] S50. Based on the synthetic torque deviation and tracking error during mode switching, the transfer process of the migration torque is corrected to form the target torque distribution state.

[0062] Specifically, during the torque transfer, the controller continuously acquires the actual output torque, position feedback, speed feedback, and operating status of the first and second stators, compares the combined torque of the two stators with the current target torque, and adjusts the transfer rate of the torque transfer and the torque commands on both sides based on the comparison results, including the following sub-steps: S501. Adjust the transfer rate of the migrating torque according to the combined torque deviation and tracking error.

[0063] Specifically, the controller determines the actual output torque on both sides based on the actual current of the first and second stators, the rotor angular position, and the corresponding stator torque characteristics, and then combines the two to obtain the actual composite torque. The difference between the current target torque and the actual composite torque is determined as the composite torque deviation. At the same time, the position tracking error and speed tracking error are updated based on the target position, actual position, target speed, and actual speed.

[0064] When both the combined torque deviation and the tracking error are within the allowable range, maintain the current transfer torque rate. When the combined torque is insufficient and the tracking error increases in the direction of deviation from the target, reduce the torque reduction rate on the release side and increase its torque increase rate within the allowable range of the remaining output on the control side. When the combined torque is too large and the actual motion state exceeds the target state, reduce the torque increase rate on the control side and adjust the torque reduction amount on the release side according to the formed transfer torque.

[0065] When the position tracking error or speed tracking error exceeds the corresponding switching limit, the torque reduction on the release side is paused, the current torque command on both the takeover and release sides is maintained, and the remaining output on both sides is used to correct the composite torque. After the tracking error recovers to the allowable range, the transfer torque is resumed at a rate lower than that before the pause to avoid the transfer process causing another sudden increase in tracking error.

[0066] The controller synchronously monitors the actual current, winding temperature, and driver temperature on both the take-up and release sides. When the operating parameters on the take-up side approach the allowable limits, its take-up torque transfer rate is reduced; when the release side reaches overheating conditions, its torque release deceleration rate is increased within the allowable range of the combined torque deviation; when protection conditions are triggered on either side, the normal take-up torque transfer is stopped and the corresponding faulty side is isolated.

[0067] S502. When the combined torque deviation and tracking error meet the allowable conditions, the transfer of migration torque is completed, and the target torque distribution state is formed.

[0068] Specifically, the controller compares the transfer torque already borne by the takeover side with the transfer torque determined in S30, and checks the remaining amount of the corresponding transfer torque on the release side. When the takeover side reaches the target amount, the release side completes the corresponding torque reduction, and the combined torque deviation, position tracking error, and speed tracking error are all continuously within the allowable range, the transfer torque transfer is determined to be complete.

[0069] When the target operating mode is the single-stator energy-saving mode, the operating stator bears the current target torque, while the torque current of the other stator drops to zero and remains in synchronous standby mode; when the target operating mode is the dual-stator cooperative mode, the first stator and the second stator respectively reach the torque bearing capacity determined according to the available torque and thermal margin, and together form the current target torque.

[0070] When the target operating mode is the dual-stator differentiated mode, the base side bears the base torque determined according to the stable target torque, and the compensation side bears the compensation torque according to the position tracking error, speed tracking error and output torque fluctuation. When the target operating mode is the fault degradation mode, the fault side remains isolated, and the healthy side bears the degraded target torque within its available torque range.

[0071] When the receiving side fails to reach the target torque capacity, or when the combined torque deviation and tracking error do not continuously meet the allowable conditions, the mode switching state is maintained and the torque commands on both sides are continuously corrected. After reaching the corresponding target torque distribution state, the actual torque capacity, operating status, and mode switching completion time of the first and second stators are recorded.

[0072] S60. Verify the target torque distribution status. If the verification passes, lock the target operating mode. If the verification fails or a fault occurs, re-execute the mode determination and switching.

[0073] Specifically, after the controller establishes the target torque distribution state in S50, it continuously monitors the position response, speed response, actual torque of the dual stators, and operating status to determine whether the mode switching result meets the stability conditions of the target operating mode. Based on the verification result, it locks the operating mode or redetermines the switching state, including the following sub-steps: S601. Verify the target torque distribution status and lock the target operating mode based on the position response, speed response and dual stator operating status.

[0074] Specifically, the controller continuously collects actual position, actual speed, actual torque of the first stator, actual torque of the second stator, dual-side current, winding temperature and driver temperature during the preset verification period, and determines the position tracking error, speed fluctuation, combined torque deviation and dual-side torque distribution deviation respectively.

[0075] When the position tracking error, speed fluctuation, and combined torque deviation are all within their respective allowable ranges, the actual torque distribution relationship between the first and second stators conforms to the target torque allocation state, and the dual-side current, temperature, and drive status meet the operating conditions of the target operating mode, the mode switching verification is considered successful. If any parameter exceeds its corresponding allowable range during the verification period, the continuous stabilization time is recalculated.

[0076] After successful verification, the controller registers the target operating mode as the current operating mode, locks the corresponding torque distribution relationship, and records the mode type, actual torque on both sides, available torque, thermal margin, and switching completion time. In single-stator energy-saving mode, the standby stator and rotor angular positions are kept synchronized; in dual-stator collaborative mode, continuous torque distribution on both sides is maintained; in dual-stator differentiated mode, the responsibilities of the basic side and the compensation side are maintained; in fault degradation mode, the faulty side is isolated and the healthy side has limited output.

[0077] During mode lock, the controller continues to update the motion status and dual-stator operating status. When the target torque, tracking error, speed change, or dual-stator availability status meets the criteria for other operating modes and the corresponding confirmation duration is met continuously, the current mode lock is released and the switching type is redefined.

[0078] S602. If the verification fails, the target operating mode is redefined. If a fault occurs, the faulty side is isolated and the healthy side performs a fault degradation switch within the available torque range.

[0079] Specifically, when the target torque distribution state fails to meet the stability conditions within the preset verification time limit, the controller regenerates the mode determination data based on the current motion stage, target torque, tracking error, and dual stator operating state. If the original target operating mode still meets the operating conditions, the continuous holding torque and transfer torque are re-determined based on the current actual torque distribution state, and the transfer torque transfer rate is reduced; if the original target operating mode no longer meets the operating conditions, the target operating mode and switching type are re-determined.

[0080] When a fault occurs in the first stator, second stator, or corresponding independent drive unit during mode determination, state preset, torque transfer, or switching verification, the controller immediately blocks the drive pulses on the faulty side and stops sending torque commands to the faulty side, determining the actual torque borne by the faulty side before the fault occurred as the torque to be taken over. The healthy side maintains its current output and determines the range of torque that can be taken over based on its available torque and thermal margin.

[0081] When the torque to be taken over does not exceed the remaining output of the healthy side, the controller increases the torque command of the healthy side to compensate for the loss of the combined torque caused by the failure of the faulty side. When the torque to be taken over exceeds the remaining output of the healthy side, the torque of the healthy side is limited to the corresponding available torque range, the system target torque is reduced, and a degraded operation flag is generated. During the takeover process of the healthy side, the torque increase rate is adjusted according to the combined torque deviation and tracking error to avoid secondary impact caused by the simultaneous occurrence of fault isolation and torque takeover.

[0082] Once a stable output is established on the healthy side, the operating mode is set to fault degradation mode, and the current, winding temperature, and driver temperature on the healthy side are continuously monitored. Torque output is stopped when the healthy side meets the protection conditions; the faulty side remains isolated and does not participate in the operating mode switching until maintenance is completed and the status verification is passed.

[0083] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-mode switching control method for an axial flux dual-stator motor, characterized in that, Includes the following steps: S10. Collect the motion state and operating state of the axial flux dual-stator motor and generate mode determination data; S20. Based on the mode determination data, determine the target operating mode from the single stator energy-saving mode, dual stator collaborative mode, dual stator differentiated mode and fault degradation mode, and determine the switching type from the current operating mode to the target operating mode. S30. Based on the torque distribution state corresponding to the current operating mode and the target operating mode, divide the switching torque into continuous holding torque and migration torque that changes the stator bearing the load, and preset the execution state of the takeover side of the migration torque. S40. Maintain continuous holding torque, gradually transfer the transfer torque from the release side to the control side, so that the combined torque of the two stators remains continuous; S50. Based on the synthetic torque deviation and tracking error during mode switching, the transfer process of the migration torque is corrected to form the target torque distribution state. S60. Verify the target torque distribution status. If the verification passes, lock the target operating mode. If the verification fails or a fault occurs, re-execute the mode determination and switching.

2. The multi-mode switching control method for an axial flux dual-stator motor according to claim 1, characterized in that, The axial flux dual-stator motor includes a first stator and a second stator arranged along the axial direction, and a rotor assembly forming an axial air gap with the first stator and the second stator. The first stator and the second stator are respectively connected to independent drive units.

3. The multi-mode switching control method for an axial flux dual-stator motor according to claim 1, characterized in that, The motion state and operating state of the axial flux dual-stator motor are collected to generate mode determination data, including the following sub-steps: S101. Determine the motion stage, target torque, and tracking error based on motion commands, position feedback, and speed feedback; S102. Determine the corresponding available torque and thermal margin based on the current, temperature and driving state of the first stator and the second stator, and form mode determination data.

4. The multi-mode switching control method for an axial flux dual-stator motor according to claim 1, characterized in that, Based on the mode determination data, the target operating mode is determined from the single-stator energy-saving mode, dual-stator collaborative mode, dual-stator differentiated mode, and fault degradation mode, and the switching type from the current operating mode to the target operating mode is determined, including the following sub-steps: S201. Determine the target operating mode based on the target torque, tracking error, speed change, and the available status of the dual stators; S202. Determine whether to switch to increased or decreased power supply, redistribution, or fault-crossing based on the difference between the current operating mode and the target operating mode.

5. The multi-mode switching control method for an axial flux dual-stator motor according to claim 1, characterized in that, Based on the torque distribution state corresponding to the current operating mode and the target operating mode, the switching torque is divided into continuous holding torque and migrating torque that changes the stator load, and the execution state of the migrating torque takeover side is preset, including the following sub-steps: S301. Compare the current torque distribution state with the target torque distribution state to determine the continuous holding torque, the transfer torque, the control side, and the release side. S302. Check the driving status and remaining output of the connecting pipe side, and initialize the current control status of the connecting pipe side according to the rotor angular position.

6. The multi-mode switching control method for an axial flux dual-stator motor according to claim 1, characterized in that, Maintaining continuous holding torque involves gradually transferring the transfer torque from the release side to the control side, ensuring the continuous synthesis torque of the dual stators. This includes the following sub-steps: S401, Maintain continuous holding torque and gradually increase the migration torque borne by the control side; S402. Reduce the migration torque borne by the release side based on the migration torque generated on the control side, and correct the torque command on both sides.

7. The multi-mode switching control method for an axial flux dual-stator motor according to claim 1, characterized in that, The process of correcting the transfer torque based on the synthetic torque deviation and tracking error during mode switching forms the target torque distribution state, including the following sub-steps: S501. Adjust the transfer rate of the migrating torque according to the combined torque deviation and tracking error; S502. When the combined torque deviation and tracking error meet the allowable conditions, the transfer of migration torque is completed, and the target torque distribution state is formed.

8. The multi-mode switching control method for an axial flux dual-stator motor according to claim 1, characterized in that, Verify the target torque distribution status. If the verification passes, lock the target operating mode. If the verification fails or a fault occurs, re-execute the mode determination and switching, including the following sub-steps: S601. Verify the target torque distribution status and lock the target operating mode based on the position response, speed response and dual stator operating status. S602. If the verification fails, the target operating mode is redefined. If a fault occurs, the faulty side is isolated and the healthy side performs a fault degradation switch within the available torque range.

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