A position sensorless control method for a dual-winding permanent magnet synchronous motor

Abstract

The present application discloses a method for controlling a dual-winding permanent magnet synchronous motor without position sensors, the method comprising: when the motor is started from zero speed, one set of windings is dragged by rotating the external synchronous open-loop rotor angle magnetomotive force; a discrete mathematical equation of a Lumberg observer is established, and a reduced-order decoupling process is performed to observe the motor rotor position in real time, and the rotor position angle required for the motor operation is output; when the drag speed frequency is higher than a preset speed frequency threshold, one set of windings is switched from open-loop dragging to Lumberg closed-loop control state; the torque required for the motor is calculated according to the target speed command; a two-dimensional system model of torque distribution of a dual-winding motor under motor power limit and fault state is established, and the torque required for the operation of each set of windings is obtained. The present application can realize the control of dual-winding permanent magnet synchronous motor without position sensors, reduce costs and solve the problem of torque distribution.

Description

Technical Field

[0001] The present application relates to the technical field of dual-winding motor control, and in particular to a position sensorless control method for a dual-winding permanent magnet synchronous motor. Background Art

[0002] Compared with traditional permanent magnet motors, dual-winding permanent magnet synchronous motors have many advantages, such as high power density, high energy conversion efficiency, high safety redundancy, and low power requirements for drive controllers. Therefore, they are widely used in aviation electric propulsion, new energy vehicles and other fields.

[0003] However, the control of dual-winding motors has problems with uniform torque distribution, as well as how to reasonably distribute torque after a fault occurs to ensure the motor continues to work reliably. In addition, the commonly used dual-winding motor control method relies on position sensors to obtain the motor rotor position signal, which not only increases the number of wiring harnesses, but also the sensor has strict environmental requirements and is not suitable for special occasions such as the aviation field. Therefore, it is particularly important to develop a position sensor-free dual-winding permanent magnet synchronous motor control method. Summary of the invention

[0004] In order to achieve position sensorless control of a dual-winding permanent magnet synchronous motor, reduce costs and solve the torque distribution problem, the present application provides a position sensorless control method for a dual-winding permanent magnet synchronous motor.

[0005] In a first aspect, the present application provides a position sensorless control method for a dual-winding permanent magnet synchronous motor, comprising the following steps:

[0006] S1. When the motor starts from zero speed, one set of windings is driven by rotating the rotor angle magnetomotive force using an external synchronous open-loop;

[0007] S2, establish a discrete mathematical equation of the Lumberg observer, and perform a reduced-order decoupling process; use the processed Lumberg observer to perform real-time state observation of the motor rotor position, and output the rotor position angle required for the motor operation;

[0008] S3, when the drag speed frequency is higher than the preset speed frequency threshold, a set of windings is switched from open-loop drag to the Lumberg closed-loop control state;

[0009] S4, calculating the torque required by the motor according to the target speed command;

[0010] S5, establishing a two-dimensional system model of torque distribution of a dual-winding motor under motor power limit and fault state, inputting the calculated torque required for the motor into the two-dimensional system model of torque distribution of the dual-winding motor, and obtaining the output torque required for each set of windings to operate;

[0011] S6. Obtain the mapping current corresponding to the torque required for the operation of each set of windings by querying the torque-current data table; input the queried currents into the two sets of windings respectively to realize the control of the dual-winding motor.

[0012] By adopting the above scheme and a position sensorless control method, the cost is reduced and the structural space required for installing the sensor is saved. When one of the windings fails, the torque can be reasonably and dynamically distributed according to the fault condition and the current allowable operating conditions, thereby reducing the risk of motor system failure shutdown.

[0013] Preferably, the relationship between the external synchronous open-loop rotor angle applied to one set of windings and the start-up time in step S1 is:

[0014] In the formula, is the external synchronous open-loop rotor angle at the current moment, is the external synchronous open-loop rotor angle at the previous moment, is the start time, is the switching cycle, is the set acceleration step; where, and It is 0 at the initial startup time.

[0015] By adopting the above scheme, according to the set acceleration step amount, a certain time is taken when the motor starts to reach a stable working state, thereby ensuring the stability and accuracy of the external synchronization signal.

[0016] Preferably, the discrete mathematical equation of the Lumberg observer in step S2 is:

[0017] In the formula, The motor is in the stationary coordinate system during the current operation cycle. Estimated axis current, The motor is in the stationary coordinate system during the previous operation cycle. Estimated axis current, is the resistance value of the motor stator winding, is the switching cycle, is the motor stator inductance, Estimate the back EMF value of the motor for the previous operation cycle, Estimate the back EMF value of the motor in the current operation cycle, The motor is in the stationary coordinate system The actual voltage value of the shaft, The motor is in the stationary coordinate system The actual current value of the axis, is the motor angular velocity, are observer gains, specifically:

[0018] In the formula, is the resistance value of the motor stator winding, is the switching cycle, is the motor stator inductance, k is the adjustment coefficient;

[0019] The calculation formula of the rotor position angle required for the motor to run in step S2 is:

[0020] in, The output of the observer is the motor rotor position angle, To estimate the back EMF value, is the proportional gain, is the integral gain, It is a continuous domain operator, and A and B are both used as intermediate transition operation identifiers of the function.

[0021] By adopting the above scheme, a Lumberg observer is designed to estimate the speed and rotor position. The back-EMF value is used as a feedback signal to improve the estimation accuracy of the speed and position. The observer gain is designed in combination with the specific parameters of the motor to optimize the estimation of the back-EMF value, thereby improving the estimation accuracy of the observer.

[0022] Preferably, in step S2, the discrete mathematical equation of the Lumberg observer is subjected to order reduction and decoupling processing, and the formula is:

[0023] .

[0024] By adopting the above scheme, the observer is reduced in order and decoupled, and the observer model is simplified, thereby improving the computational efficiency, improving the system stability and enhancing the robustness of the system.

[0025] Preferably, when the drag speed frequency is higher than a preset speed frequency threshold, a set of windings is switched from open-loop drag to a Lumberg closed-loop control state in step S3, specifically including:

[0026] When the speed frequency is higher than the preset speed frequency threshold, the external synchronous open-loop rotor angle is compared with the observer output motor rotor position angle. When the difference is less than the preset angle, the external synchronous open-loop rotor angle is gradually approached to the observer output motor rotor position angle, and finally the observer output motor rotor position angle is cut into the motor decoupling operation.

[0027] The difference err The calculation formula is:

[0028] In the formula, Output the motor rotor position angle for the observer; is the external synchronous open-loop rotor angle.

[0029] By adopting the above scheme and comparing the angle difference, the open-loop dragging of the given angle gradually approaches the observer output angle until the two finally coincide and the open-loop angle dragging is completed and the observer output angle enters the closed-loop control state, thereby ensuring the subsequent accurate calculation of the torque required to be applied by the motor.

[0030] Preferably, the formula for calculating the torque required to be applied by the motor according to the target speed instruction in step S4 is:

[0031] In the formula, is the total required torque of the dual-winding motor, is the target speed, v is the motor running feedback speed, is the proportional gain, is the integral gain, and s is the continuous domain operator.

[0032] By adopting the above solution, since it has switched to a closed-loop control state, the feedback speed and the target speed can be calculated to obtain calculation parameters for subsequent torque distribution.

[0033] Preferably, the two-dimensional system model of torque distribution of the dual-winding motor in step S5 is:

[0034] In the formula, is the total required torque of the dual-winding motor, are the torques distributed to the two sets of windings, is the torque distribution coefficient; is the redundancy coefficient at the last operation cycle i, j is the redundancy factor; is the redundancy coefficient at the current operation cycle i+1, j is the redundancy factor.

[0035] By adopting the above scheme and introducing a redundancy factor, the failure or malfunction of certain components in the system can be tolerated to a certain extent, thereby ensuring that the entire motor system can continue to operate in the event of a partial failure, thereby improving the reliability and stability of the system; and after considering the redundancy factor, the torque of the two windings can be more reasonably distributed according to the actual operating conditions and load requirements of the motor, thereby achieving more efficient energy conversion and smoother operation.

[0036] Preferably, the step S6 of querying the torque-current data table to obtain the mapping current corresponding to the torque required for each set of windings to run; inputting the queried currents into the two sets of windings respectively to realize the control of the dual-winding motor specifically includes:

[0037] The torque-current data table is formed by bench motor calibration, and the torque required for each set of windings is input. The binary method is used to look up the table to determine the interval of the torque required for each set of windings. The forward and backward interpolation linear fitting is performed to obtain the mapping current, that is, the mapping current corresponding to the torque required for each set of windings is obtained;

[0038] The queried current is input into the two sets of windings respectively, and the control of the dual-winding motor is realized through current closed-loop compensation calculation, Park transformation and space vector pulse width modulation.

[0039] By adopting the above solution and using the torque-current data table, the most suitable current value can be quickly found to match the current torque demand, thereby achieving precise motor control with high efficiency and fast response speed, and avoiding the motor from operating under adverse conditions such as overload or overcurrent, thereby protecting the motor from damage.

[0040] In a second aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the method as described above.

[0041] In a third aspect, the present application provides a computer device, comprising a memory, a processor, and a program stored and executable on the memory, wherein the program implements the steps of the above method when executed by the processor.

[0042] In summary, this application has the following beneficial effects:

[0043] 1. The sensorless control method is adopted to reduce costs and save the structural space required for installing sensors;

[0044] 2. When one of the windings fails or fails continuously, the torque can be reasonably and dynamically distributed according to the fault characteristics and the current allowable operating conditions to reduce the risk of motor system failure and shutdown. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of the position sensorless control method of the dual-winding permanent magnet synchronous motor described in a specific embodiment;

[0046] Figure 2 It is a schematic diagram of switching between the external synchronous open-loop rotor angle and the observer output motor rotor position angle in the position sensorless control method of the dual-winding permanent magnet synchronous motor described in the specific embodiment;

[0047] Figure 3 It is a waveform diagram of the external synchronous open-loop rotor angle and the observer output motor rotor position angle switching measured in the position sensorless control method of the dual-winding permanent magnet synchronous motor described in the specific embodiment;

[0048] Figure 4 It is a diagram of the motor torque distribution in the position sensorless control method of the dual-winding permanent magnet synchronous motor described in the specific embodiment. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0050] like Figure 1 As shown, the embodiment of the present application discloses a position sensorless control method for a dual-winding permanent magnet synchronous motor, and the specific steps are as follows:

[0051] S1. When the motor starts from zero speed, one set of windings is driven by rotating the rotor angle magnetomotive force using an external synchronous open-loop.

[0052] Specifically, when the motor starts from zero speed, one of the windings is dragged by rotating it using an external synchronous open-loop rotor angle magnetomotive force. That is, through external signal synchronization, open-loop control of the rotor angle, and use of magnetomotive force to generate rotational force and other control technologies, a set of windings in the motor is given an external synchronous open-loop rotor angle (abbreviated as: open-loop angle) for dragging control.

[0053] Among them, the relationship between the rotor angle and the starting time of applying an external synchronous open loop to one set of windings is as follows:

[0054] In the formula, is the external synchronous open-loop rotor angle at the current moment, is the external synchronous open-loop rotor angle at the previous moment, is the start time, is the switching cycle, is the set acceleration step; where, and It is 0 at the initial startup time.

[0055] S2. Establish the discrete equation of the Lumberg observer, perform order reduction and decoupling processing, observe the motor rotor position in real time, and output the rotor position angle required for the motor operation.

[0056] Specifically, a Lumberg observer discrete equation is established in advance, and the Lumberg observer discrete equation is specifically:

[0057] In the formula, The motor is in the stationary coordinate system during the current operation cycle. Estimated axis current, The motor is in the stationary coordinate system during the previous operation cycle. Estimated axis current, is the resistance value of the motor stator winding, is the switching cycle, is the motor stator inductance, Estimate the back EMF value of the motor for the previous operation cycle, Estimate the back EMF value of the motor in the current operation cycle, The motor is in the stationary coordinate system The actual voltage value of the shaft, The motor is in the stationary coordinate system The actual current value of the axis, is the motor angular velocity, are observer gains, specifically:

[0058] In the formula, is the resistance value of the motor stator winding, is the switching cycle, is the motor stator inductance, and k is the adjustment coefficient.

[0059] The pre-established Lumberg observer discrete equation is subjected to order reduction and decoupling processing, and the Lumberg observer discrete equation after processing is:

[0060]

[0061] The processed Lumberg observer is used to observe the motor rotor position in real time and output the rotor position angle required for the motor to run. The calculation formula for the rotor position angle required for the motor to run is:

[0062] in, The output of the observer is the motor rotor position angle, To estimate the back EMF value, is the proportional gain, is the integral gain, It is a continuous domain operator, and A and B are both used as intermediate transition operation identifiers of the function.

[0063] S3: When the drag speed frequency is higher than the preset speed frequency threshold, the open-loop drag is switched to the Lumberg closed-loop control state.

[0064] Specifically, the preset speed frequency threshold is 10% of the motor base frequency; the method of dragging a set of windings in the motor from the external synchronous open-loop rotor angle to the observer output motor rotor position angle to enter the closed-loop control state specifically includes:

[0065] When the speed frequency is 10% higher than the motor base frequency, Figure 2As shown, the difference between the external synchronous open-loop rotor angle and the observer output motor rotor position angle is compared. When the difference is less than the preset angle (which can be a manually set value), the external synchronous open-loop rotor angle is gradually approached to the observer output motor rotor position angle, and finally the observer output motor rotor position angle is cut into the motor decoupling operation; Figure 3 As shown in the figure, it can be seen that when the cut-in is performed, the open-loop dragging given angle begins to gradually approach the observer output angle until the two finally coincide and completely cut into the decoupling operation performed by the observer angle.

[0066] In order to approximate smoothly, the adaptive control method is started to gradually adjust the system angle according to the observer feedback. During the approximation process, the control parameters are dynamically adjusted according to the real-time data fed back by the observer to ensure that the system can approach the target angle smoothly and quickly. When the system reaches or approaches the target angle, the approximation process is stopped and the current state is maintained. In addition, once the output of the observer fluctuates abnormally, that is, the observed value exceeds the threshold range, compensation measures are triggered, such as suspending the approximation process or using alternative observation data to ensure the stability and accuracy of the approximation process.

[0067] Among them, the difference err The calculation formula is:

[0068] In the formula, Output the motor rotor position angle for the observer; is the external synchronous open-loop rotor angle.

[0069] S4. Calculate the torque required by the motor according to the target speed command.

[0070] Specifically, since the motor winding enters a closed-loop control state, the motor running feedback speed is obtained, such as Figure 4 As shown, the torque required by the motor is calculated in combination with the target speed command; the specific formula is:

[0071] In the formula, is the total required torque of the dual-winding motor, is the target speed, v is the motor running feedback speed, is the proportional gain, is the integral gain, and s is the continuous domain operator.

[0072] S5. Establish a two-dimensional system model of torque distribution of a dual-winding motor under motor power limit and fault conditions, and calculate the output torque required for each set of windings to operate.

[0073] Specifically, the two-dimensional system model of torque distribution of dual-winding motor is established as:

[0074] In the formula, is the total required torque of the dual-winding motor, are the torques distributed to the two sets of windings, is the torque distribution coefficient; is the redundancy coefficient at the last operation cycle i, j is the redundancy factor; is the redundancy coefficient at the current operation cycle i+1, j is the redundancy factor.

[0075] The torque distribution coefficient is obtained according to the state of the two windings, and a torque distribution coefficient table is pre-set according to the historical fault state, and the torque distribution coefficient is obtained by looking up the table by detecting the fault state during operation; wherein, a torque distribution coefficient table is pre-set according to the historical fault state. An experimental measurement method can be used to measure the motor performance under different redundancy coefficients under different fault states, and then determine the most appropriate redundancy coefficient; or a simulation method can be used to simulate the operation of the motor under different redundancy coefficients under different states, so as to determine the most appropriate redundancy coefficient; or a deep learning model is trained based on the evaluation results of experts under different redundancy coefficients under different fault states, so as to complete the determination of the most appropriate redundancy coefficient.

[0076] For example: if it is detected that both windings are normal, the coefficient is 0.5, which means that they work together; if one of the windings fails, the corresponding torque distribution coefficient is obtained according to the detected fault level.

[0077] According to the required applied torque of the motor calculated in step S4, the dual-winding motor torque distribution two-dimensional system model is input, and the output torque required for each set of windings to operate is obtained according to the above formula.

[0078] In addition, if the detection result shows that a continuous fault has occurred, even if the next cycle state is normal, it does not mean that it can fully meet the requirements. Therefore, when a continuous fault occurs, the torque distribution of the next cycle can be predicted based on the fault state of the previous and next cycles, avoiding the intermittent recovery of the fault causing the torque distribution to fluctuate and cause the motor control to oscillate, and has the characteristics of smooth torque output.

[0079] For example, if a fault is detected for three consecutive cycles, the coefficient for predicting the next (fourth) cycle is , thus predicting the torque distribution value of the next cycle.

[0080] S6. The calculated torque is obtained by looking up the table and the current is input into the two sets of windings respectively to realize the control of the dual-winding motor.

[0081] Specifically, a torque-current (T,i) data table is formed through bench motor calibration, the torque required for each set of windings is input, and the binary method is used to look up the table to determine the interval of the torque required for each set of windings. The forward and backward interpolation linear fitting is performed to obtain the mapping current, that is, the mapping current corresponding to the torque required for each set of windings is obtained.

[0082] like Figure 4 As shown, the queried current is respectively input into the two sets of windings, and the control of the dual-winding motor is realized through current closed-loop compensation calculation, Park transformation and space vector pulse width modulation; wherein, when the input current is subjected to PARK transformation, the angle difference between the external synchronous open-loop rotor angle and the observer output motor rotor position angle is also compensated.

[0083] The embodiment of the present application also discloses a computer-readable storage medium.

[0084] Specifically, the computer-readable storage medium stores a computer program that can be loaded by a processor and executed such as the above-mentioned dual-winding permanent magnet synchronous motor position sensorless control method. The computer-readable storage medium includes, for example: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0085] The embodiment of the present application also discloses a computer device.

[0086] Specifically, the computer device includes a memory and a processor, and the memory stores a computer program that can be loaded by the processor and execute the above-mentioned dual-winding permanent magnet synchronous motor position sensorless control method.

[0087] The above are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Any feature disclosed in this specification (including the abstract and drawings), unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

Claims

1. A position sensorless control method for a dual-winding permanent magnet synchronous motor, characterized in that: include: S1. When the motor starts from zero speed, one set of windings is driven by rotating the rotor angle magnetomotive force using an external synchronous open-loop; S2, establish a discrete mathematical equation of the Lumberg observer, and perform a reduced-order decoupling process; use the processed Lumberg observer to perform real-time state observation of the motor rotor position, and output the rotor position angle required for the motor operation; S3, when the drag speed frequency is higher than the preset speed frequency threshold, a set of windings is switched from open-loop drag to the Lumberg closed-loop control state; S4, calculating the torque required by the motor according to the target speed command; S5, establishing a two-dimensional system model of torque distribution of a dual-winding motor under motor power limit and fault state, inputting the calculated torque required for the motor into the two-dimensional system model of torque distribution of the dual-winding motor, and obtaining the output torque required for each set of windings to operate; S6. Obtain the mapping current corresponding to the torque required for each set of windings to run by querying the torque-current data table; input the queried currents into the two sets of windings respectively to realize the control of the dual-winding motor; The discrete mathematical equation of the Lumberg observer in step S2 is: In the formula, The motor is in the stationary coordinate system during the current operation cycle. Estimated axis current, The motor is in the stationary coordinate system during the previous operation cycle. Estimated axis current, is the resistance value of the motor stator winding, is the switching cycle, is the motor stator inductance, Estimate the back EMF value of the motor for the previous operation cycle, Estimate the back EMF value of the motor in the current operation cycle, The motor is in the stationary coordinate system The actual voltage value of the shaft, The motor is in the stationary coordinate system The actual current value of the axis, is the motor angular velocity, are observer gains, specifically: In the formula, is the resistance value of the motor stator winding, is the switching cycle, is the motor stator inductance, k is the adjustment coefficient; The calculation formula of the rotor position angle required for the motor to run in step S2 is: in, The output of the observer is the motor rotor position angle, To estimate the back EMF value, is the proportional gain, is the integral gain, It is a continuous domain operator, and A and B are both used as the intermediate transition operation identifiers of the function; The formula for calculating the torque required by the motor according to the target speed instruction in step S4 is: In the formula, is the total required torque of the dual-winding motor, is the target speed, v is the motor running feedback speed, is the proportional gain, is the integral gain, s is the continuous domain operator; The two-dimensional system model of the dual-winding motor torque distribution in step S5 is: In the formula, is the total required torque of the dual-winding motor, are the torques distributed to the two sets of windings, is the torque distribution coefficient; is the redundancy coefficient at the last operation cycle i, j is the redundancy factor; is the redundancy coefficient at the current operation cycle i+1, j is the redundancy factor.

2. The position sensorless control method for a dual-winding permanent magnet synchronous motor according to claim 1, characterized in that: The relationship between the external synchronous open-loop rotor angle and the start time applied to one set of windings in step S1 is: In the formula, is the external synchronous open-loop rotor angle at the current moment, is the external synchronous open-loop rotor angle at the previous moment, is the start time, is the switching cycle, is the set acceleration step; where, and It is 0 at the initial startup time.

3. The position sensorless control method for a dual-winding permanent magnet synchronous motor according to claim 1, characterized in that: In the step S2, the discrete mathematical equation of the Lumberg observer is subjected to order reduction and decoupling processing, and the formula is: 。 4. The position sensorless control method for a dual-winding permanent magnet synchronous motor according to claim 1, characterized in that: When the drag speed frequency is higher than the preset speed frequency threshold, a set of windings is switched from open-loop drag to Lumberg closed-loop control state, which specifically includes: When the speed frequency is higher than the preset speed frequency threshold, the external synchronous open-loop rotor angle is compared with the observer output motor rotor position angle. When the difference is less than the preset angle, the external synchronous open-loop rotor angle is gradually approached to the observer output motor rotor position angle, and finally the observer output motor rotor position angle is cut into the motor decoupling operation; the difference err The calculation formula is: In the formula, Output the motor rotor position angle to the observer; is the external synchronous open loop rotor angle.

5. The position sensorless control method for a dual-winding permanent magnet synchronous motor according to claim 1, characterized in that: Step S6, by querying the torque-current data table, obtaining the mapping current corresponding to the torque required for each set of windings to run; inputting the queried currents into the two sets of windings respectively, to achieve control of the dual-winding motor, specifically includes: The torque-current data table is formed by bench motor calibration, and the torque required for each set of windings is input. The binary method is used to look up the table to determine the interval of the torque required for each set of windings. The forward and backward interpolation linear fitting is performed to obtain the mapping current, that is, the mapping current corresponding to the torque required for each set of windings is obtained; The queried current is input into the two sets of windings respectively, and the control of the dual-winding motor is realized through current closed-loop compensation calculation, Park transformation and space vector pulse width modulation.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 5.

7. A computer device, characterized in that: The computer device comprises a memory, a processor and a program stored and executable on the memory, and the program implements the steps of the method according to any one of claims 1 to 5 when executed by the processor.

Images