A distributed control method for a multiphase permanent magnet motor

Abstract

The application discloses a kind of multiphase permanent magnet motor distributed control method, belong to motor control technical field, including the dq axis inductance calculation of multiphase permanent magnet synchronous motor, specifically including the following steps: step one: according to the structure of multiple sets of windings of multiphase motor, establish multiphase permanent magnet synchronous motor mathematical model;Step two: according to the mathematical model of multiphase permanent magnet synchronous motor, establish coupled inductance equivalent incremental relationship, for calculating mutual inductance compensation amount of multiple sets of windings;Step three: complete calculation, obtain total inductance on each set of windings.This method reveals the equivalent effect mechanism of mutual inductance on d-q axis inductance from voltage equation level, and accordingly proposes compensation control strategy, which has important theoretical significance and engineering application value for improving the control accuracy and operation reliability of multiphase permanent magnet synchronous motor under complex working conditions.

Description

Technical Field

[0001] This invention belongs to the field of motor control technology, and in particular relates to a distributed control method for a multiphase permanent magnet motor. Background Technology

[0002] Multiphase permanent magnet synchronous motors are mainly used in fields with extremely high requirements for power density, reliability, and fault tolerance, such as ship electric propulsion, aerospace, electric vehicles, and wind power generation. Compared with traditional three-phase motors, multiphase motors, with their multi-channel redundancy design, can achieve controllable derating in fault conditions rather than hard shutdown, and also have significant advantages such as low torque ripple and high power output at low voltage. However, the increase in the number of phases also brings serious challenges: the mathematical model of a multiphase motor is represented as a high-order inductance matrix in the natural coordinate system, and the self-inductance and mutual inductance between each phase winding exhibit strong nonlinear coupling characteristics. Especially in sensorless control, the mutual inductance between phases can seriously interfere with the position estimation accuracy of the position observer, leading to a deterioration in control performance.

[0003] Currently, although existing distributed motor drive control systems at home and abroad have achieved multi-phase and multi-group independent drive control, there is a lack of a collaborative compensation mechanism that takes into account mutual inductance coupling between the distributed control units. Summary of the Invention

[0004] To address the shortcomings and deficiencies of existing technologies, this invention proposes a distributed control method for multiphase permanent magnet motors. This method reveals the equivalent effect mechanism of mutual inductance on the dq-axis inductance at the voltage equation level, and based on this, proposes a compensation control strategy. This has significant theoretical and engineering application value for improving the control accuracy and operational reliability of multiphase permanent magnet synchronous motors under complex operating conditions.

[0005] The technical problem solved by this invention is addressed by the following technical solution: A distributed control method for a multiphase permanent magnet synchronous motor, including the calculation of the dq-axis inductance of the multiphase permanent magnet synchronous motor, specifically includes the following steps: Step 1: Based on the multi-winding structure of the multi-phase motor, establish a mathematical model of the multi-phase permanent magnet synchronous motor; Step 2: Based on the mathematical model of the multiphase permanent magnet synchronous motor, establish the equivalent incremental relationship of the coupled inductance, which is used to calculate the mutual inductance compensation of multiple windings; Step 3: Complete the calculation to obtain the total inductance on each winding.

[0006] Furthermore, the mathematical model of the multiphase permanent magnet synchronous motor includes voltage equations and flux linkage equations. The voltage equation: , The magnetic flux linkage equation: , In the formula, Rs Indicates stator resistance. U dq This represents the voltage across the dq axis. I dq This represents the current in the dq axis system. ψ dq Indicates the magnetic flux linkage of the dq axis system. ψ f Indicates permanent magnet flux linkage. The cross-coupling matrix of the dq axis system. For the dq axis inductance matrix, It represents electric angular velocity.

[0007] Furthermore, based on the voltage equation and the flux linkage equation, the first set of steady-state voltage equations for the winding is established: , In the formula, u d1 Indicates the first set of windings d Axis voltage, u q1 This represents the q-axis voltage of the first winding. i d1 、i q1 These represent the d-axis current and q-axis current of the first winding, respectively. i d2 、i d3 、i d4 These represent the d-axis currents of the second, third, and fourth windings, respectively. i q2 、i q3 、i q4 These represent the q-axis currents of the second, third, and fourth windings, respectively. R s L represents the stator resistance. d This indicates the self-inductance along the d-axis of a single winding. L q This indicates the self-inductance of a single winding along its own q-axis. L d12 、L d13 、L d14 These represent the d-axis mutual inductance between the first winding and the second, third, and fourth windings, respectively. Lq12 、L q13 、L q14 These represent the q-axis mutual inductance between the first winding and the second, third, and fourth windings, respectively.

[0008] Furthermore, in the mathematical model of the multiphase permanent magnet synchronous motor, the spatial arrangement of the multiphase motor windings, with each set of windings differing from the others... x °, each winding generates mutual inductance with adjacent windings, and the magnitude of the mutual inductance depends on the spatial angle between each winding.

[0009] Furthermore, the equivalent incremental relationship of the coupled inductance is as follows: The equivalent mutual inductance of the other windings on the first winding is: , , L d1m， L q1m These are the mutual inductances of all other windings superimposed on the dq axis of the first winding, respectively. L d21， L q21 These are the mutual inductances of the second set of windings on the dq axis of the first set of windings. L d31， L q31 The mutual inductance of the third set of windings on the dq axis of the first set of windings... L d21， L q21 These are the mutual inductances of the nth winding on the dq axis of the first winding, respectively. K 1 - K n The weighting coefficient has a value of (0 - 1) and can be used to adjust the current of each winding when they are different in distributed control. n is the number of windings.

[0010] Furthermore, the total inductance is: , , In the formula, L dtotal ，L qtotal These are the total inductances of the first winding on the dq axis. L d1m， L q1mThese represent the mutual inductance of all other windings superimposed on the dq axis of the first winding. L d， L q This refers to the dq-axis inductance of this winding.

[0011] A distributed control system for a multiphase permanent magnet motor, characterized in that, for implementing any of the methods described above, it specifically includes: The modeling module is used to establish a mathematical model of a multiphase permanent magnet synchronous motor based on the structure of the multiple windings of the multiphase motor. The mutual inductance compensation calculation module is used to establish the equivalent incremental relationship of coupled inductance based on the mathematical model of the multiphase permanent magnet synchronous motor, and to calculate the mutual inductance compensation of multiple windings. The inductance calculation module is used to calculate the mutual inductance compensation amount and obtain the total inductance of each winding.

[0012] An electronic device includes at least one processor and at least one memory, wherein the processor may include one or more processing cores, the processor executes instructions, programs, code sets or instruction sets stored in the memory, and calls data stored in the memory to perform any of the methods described above.

[0013] A computer-readable storage device, wherein computer program instructions are permanently stored therein, and when the computer program instructions are invoked and loaded by a processor and executed, the method described in any of the preceding claims is performed.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Applicable to accurate dq axis inductance calculation of multiphase permanent magnet synchronous motors; 2. Compensate for mutual inductance according to the windings of the multiphase motor to make the model more accurate; 3. It can be used to adjust the mutual inductance when the currents of each winding are different in distributed control, making the model more accurate; 4. Applicable to modules that use dq axis inductors of multiphase permanent magnet synchronous motors, such as MTPA, position observers, etc. Attached Figure Description

[0015] Figure 1 Spatial arrangement of windings for multiphase motors.

[0016] Figure 2 This is a schematic diagram of the rotational speed error without mutual inductance compensation, with an observer error of 12°.

[0017] Figure 3 A schematic diagram of the rotational speed error when mutual inductance compensation is added, with an observer error of 3°. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] A distributed control method for a multiphase permanent magnet motor includes the following steps: Step 1: Establish the mathematical model of the multiphase permanent magnet synchronous motor. This embodiment uses a twelve-phase motor as an example. The mathematical model of the multiphase permanent magnet synchronous motor includes voltage equations and flux linkage equations, as follows: Voltage equation: , Magnetic flux linkage equation: , In the formula, R s Indicates stator resistance. This represents the voltage across the dq axis. This represents the current in the dq axis system. Indicates the magnetic flux linkage of the dq axis system. Indicates permanent magnet flux linkage. The cross-coupling matrix of the dq axis system. For the dq axis inductance matrix, Indicates electric angular velocity; Taking a motor model with one set of windings as an example, the steady-state voltage equation is established: , In the formula, u d1 Indicates the first set of windings d Axis voltage, u q1 This represents the q-axis voltage of the first winding. i d1 、i q1 These represent the d-axis current and q-axis current of the first winding, respectively. i d2 、i d3 、i d4 These represent the d-axis currents of the second, third, and fourth windings, respectively. i q2 、i q3 、i q4These represent the q-axis currents of the second, third, and fourth windings, respectively. R s L represents the stator resistance. d This indicates the self-inductance along the d-axis of a single winding. L q This indicates the self-inductance of a single winding along its own q-axis. L d12 、L d13 、L d14 These represent the d-axis mutual inductance between the first winding and the second, third, and fourth windings, respectively. L q12 、L q13 、L q14 These represent the q-axis mutual inductance between the first winding and the second, third, and fourth windings, respectively.

[0020] Since the dq current of each winding can be approximated as equal in actual control, the steady-state voltage equation can be rewritten as: As can be seen from the above formula, after considering the coupled inductance, the coupled inductance can be equivalent to increasing the dq axis inductance.

[0021] Step 2: Calculate the mutual inductance compensation amount The fundamental reason for mutual inductance in multiphase motors lies in the fact that the magnetic fields of all windings are established within the same common magnetic circuit (i.e., the motor core). When a phase winding is energized, the magnetic flux it generates not only passes through its own coil (forming self-inductance) but also partially passes through the windings of other phases. This physical phenomenon, where the magnetic field of one coil induces magnetic flux in another coil, generates mutual inductance. The more phases a motor has, the more potential magnetic coupling paths it has. Studies have shown that the number of magnetic couplings between phases increases rapidly with the number of phases. Furthermore, the specific structure of the motor also affects mutual inductance.

[0022] For example, changes in rotor position alter the magnetic reluctance of the magnetic circuit, thus changing the mutual inductance value; and different winding methods directly affect the distribution of the magnetic field and the coupling strength, making the influence of mutual inductance significant.

[0023] See appendix Figure 1 The diagram shows the spatial arrangement of the multiphase motor windings, with each set of windings having a phase difference. x ° As shown in the figure, each winding will generate mutual inductance to the adjacent windings, and the magnitude of the influence depends on the spatial angle between each winding. Therefore, this method uses the equivalent incremental relationship of coupled inductance to superimpose the mutual inductance.

[0024] Taking the first winding as an example, the equivalent mutual inductance of the other windings on the first winding is as follows: L d1m， L q1m This refers to the total mutual inductance of all other windings superimposed on the dq axis of the first winding. L d21， L q21 These are the mutual inductances of the second set of windings on the dq axis of the first set of windings. L d31， L q31 The mutual inductance of the third set of windings on the dq axis of the first set of windings... L d21， L q21 These are the mutual inductances of the nth winding on the dq axis of the first winding, respectively. K 1 - K n The weighting coefficient has a value of (0 - 1) and can be used to adjust the current of each winding when they are different in distributed control. n is the number of windings.

[0025] The final total inductance of the first winding is: The total inductance of the other windings can be deduced from that of the first winding. L d， L q This refers to the dq-axis inductance of this winding.

[0026] At this point, the total inductance on each winding can be... L dtotal ，L qtotal They are used separately in the independent control of each winding, and in modules that require precise inductance parameters, such as MTPA, MTPV, position observer and other calculation modules.

[0027] Combined with appendix Figure 2 , 3 As shown, the method of this embodiment is verified: see Appendix Figure 2 As shown, without mutual inductance compensation, the observer error is 12°; (See attached image) Figure 3As shown, with mutual inductance compensation, the observer error is 3°, demonstrating the effectiveness of the method in this embodiment.

[0028] A distributed control system for a multiphase permanent magnet motor includes: The modeling module is used to establish a mathematical model of a multiphase permanent magnet synchronous motor based on the structure of the multiple windings of the multiphase motor. The mutual inductance compensation calculation module is used to establish the equivalent incremental relationship of coupled inductance based on the mathematical model of the multiphase permanent magnet synchronous motor, and to calculate the mutual inductance compensation of multiple windings. The inductance calculation module is used to calculate the mutual inductance compensation amount and obtain the total inductance of each winding.

[0029] The serial numbers in the above embodiments are for descriptive purposes only and do not represent the chronological order of assembly or use of the components. Those skilled in the art will understand that the embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0030] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0031] Unless otherwise specifically stated, the relative steps, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0032] This application also provides an electronic device, which may include at least one processor and at least one memory. The processor may include one or more processing cores. The processor connects to various parts of the server using various interfaces and lines, and performs various functions of the server and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory, and by calling data stored in the memory.

[0033] This application also provides a computer-readable storage medium storing instructions. When executed by one or more processors, these instructions cause an electronic device to perform one or more of the methods described in the above embodiments.

[0034] Furthermore, the functional units in this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0035] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and the disclosure of practical truth. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure. The specification and embodiments are considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

Claims

1. A distributed control method for a multiphase permanent magnet motor, characterized in that, This includes the calculation of the dq axis inductance of a multiphase permanent magnet synchronous motor, specifically comprising the following steps: Step 1: Based on the multi-winding structure of the multi-phase motor, establish a mathematical model of the multi-phase permanent magnet synchronous motor; Step 2: Based on the mathematical model of the multiphase permanent magnet synchronous motor, establish the equivalent incremental relationship of the coupled inductance, which is used to calculate the mutual inductance compensation of multiple windings; Step 3: Complete the calculation to obtain the total inductance on each winding.

2. The distributed control method for a multiphase permanent magnet motor according to claim 1, characterized in that, The mathematical model of the multiphase permanent magnet synchronous motor includes voltage equations and flux linkage equations. The voltage equation: , The magnetic flux linkage equation: , In the formula, R s Indicates stator resistance. U dq This represents the voltage across the dq axis. I dq This represents the current in the dq axis system. ψ dq Indicates the magnetic flux linkage of the dq axis system. ψ f Indicates permanent magnet flux linkage. The cross-coupling matrix of the dq axis system. For the dq axis inductance matrix, It represents electric angular velocity.

3. The distributed control method for a multiphase permanent magnet motor according to claim 2, characterized in that, Based on the voltage equation and the flux linkage equation, establish the first set of steady-state voltage equations for the winding: ， In the formula, u d1 Indicates the first set of windings d Axis voltage, u q1 This represents the q-axis voltage of the first winding. i d1 、i q1 These represent the d-axis current and q-axis current of the first winding, respectively. i d2 、i d3 、i d4 These represent the d-axis currents of the second, third, and fourth windings, respectively. i q2 、i q3 、i q4 These represent the q-axis currents of the second, third, and fourth windings, respectively. R s L represents the stator resistance. d This indicates the self-inductance along the d-axis of a single winding. L q This indicates the self-inductance of a single winding along its q-axis. L d12 、L d13 、L d14 These represent the d-axis mutual inductance between the first winding and the second, third, and fourth windings, respectively. L q12 、L q13 、L q14 These represent the q-axis mutual inductance between the first winding and the second, third, and fourth windings, respectively.

4. The distributed control method for a multiphase permanent magnet motor according to claim 3, characterized in that, The mathematical model of the multiphase permanent magnet synchronous motor describes the spatial arrangement of the multiphase motor windings, with each set of windings having mutual differences. x °, each winding generates mutual inductance with adjacent windings, and the magnitude of the mutual inductance depends on the spatial angle between each winding.

5. The distributed control method for a multiphase permanent magnet motor according to claim 4, characterized in that, The equivalent incremental relationship of the coupled inductance is as follows: The equivalent mutual inductance of the other windings on the first winding is: ， ， L d1m， L q1m These are the mutual inductances of all other windings superimposed on the dq axis of the first winding, respectively. L d21， L q21 These are the mutual inductances of the second set of windings on the dq axis of the first set of windings. L d31， L q31 The mutual inductance of the third set of windings on the dq axis of the first set of windings... L d21， L q21 These are the mutual inductances of the nth winding on the dq axis of the first winding, respectively. K 1 - K n The weighting coefficient has a value of (0 - 1) and can be used to adjust the current of each winding when they are different in distributed control. n is the number of windings.

6. The distributed control method for a multiphase permanent magnet motor according to claim 5, characterized in that, The total inductance is: ， ， In the formula, L dtotal ，L qtotal These represent the total inductance of all other windings on the dq axis of the first winding. L d1m， L q1m These represent the total superimposed mutual inductance of the first set of windings on the dq axis. L d， L q This refers to the dq-axis inductance of this winding.

7. A distributed control system for a multiphase permanent magnet motor, characterized in that, To implement the method as described in any one of claims 1 to 6, specifically comprising: The modeling module is used to establish a mathematical model of a multiphase permanent magnet synchronous motor based on the structure of the multiple windings of the multiphase motor. The mutual inductance compensation calculation module is used to establish the equivalent incremental relationship of coupled inductance based on the mathematical model of the multiphase permanent magnet synchronous motor, and to calculate the mutual inductance compensation of multiple windings. The inductance calculation module is used to calculate the mutual inductance compensation amount and obtain the total inductance of each winding.

8. An electronic device, characterized in that, It includes at least one processor and at least one memory, wherein the processor may include one or more processing cores, the processor executes instructions, programs, code sets or instruction sets stored in the memory, and calls data stored in the memory to perform the method as described in any one of claims 1 to 6.

9. A computer-readable storage device, characterized in that, The storage device contains computer program instructions, which are invoked and loaded by the processor and executed to perform the method as described in any one of claims 1 to 6.

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