Motor control method and device

Abstract

The present invention provides a motor control method and device. The motor control method is applied to a permanent magnet synchronous motor (PMSM) based on a single resistor field oriented control (FOC), and the method includes the following steps: in the space vector modulation stage of the PMSM, detecting the time window of the non-zero voltage vector; judging whether the time window satisfies a preset minimum sampling window; and updating the non-zero voltage vector duty cycle in the space vector modulation stage when the time window satisfies the preset minimum sampling window. The technical solution of the embodiment of the present invention can reduce the motor working noise caused by the single resistor FOC phase shift, while also reducing the cost and improving the motor control effect.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a motor control method and device. Background Art

[0002] Permanent magnet synchronous motor (PMSM) is widely used in various drive fields due to its excellent performance. However, certain fields have certain requirements for noise. In order to control its working noise, the dual-resistance FOC solution or pseudo-sine (non-vector) solution is often used in related technologies. However, the dual-resistance FOC solution uses many components and is costly; and the pseudo-sine solution cannot control its dynamic response characteristics more stably like the FOC solution due to its chip characteristics. It can be seen that the existing PMSM control method needs to be improved. Summary of the invention

[0003] The embodiments of the present invention provide a motor control method and device to improve the control effect on a PMSM.

[0004] To solve the above problems, the present invention is achieved as follows:

[0005] In a first aspect, the present invention provides a motor control method, which is applied to a permanent magnet synchronous motor (PMSM) based on single resistor field oriented control (FOC), and the method comprises the following steps:

[0006] During the space vector modulation phase of the PMSM, detecting a time window in which a non-zero voltage vector acts;

[0007] Determine whether the time window meets the preset minimum sampling window;

[0008] When the time window satisfies a preset minimum sampling window, the non-zero voltage vector duty cycle of the space vector modulation stage is updated.

[0009] In some embodiments, before updating the non-zero voltage vector duty cycle in the space vector modulation stage, the method further includes:

[0010] Record the cumulative number of times that the time window does not meet the preset minimum sampling window;

[0011] When the accumulated number of times is less than a preset threshold, the non-zero voltage vector duty cycle in the space vector modulation stage is maintained.

[0012] In some embodiments, updating the non-zero voltage vector duty cycle in the space vector modulation stage includes:

[0013] When the accumulated number reaches a preset threshold, the non-zero voltage vector duty cycle in the space vector modulation stage is updated.

[0014] In some embodiments, updating the non-zero voltage vector duty cycle in the space vector modulation stage includes:

[0015] The time window of the non-zero voltage vector action is expanded so that the time window of the non-zero voltage vector action is not less than the minimum sampling time.

[0016] In some embodiments, the method further comprises:

[0017] When the time window meets the preset minimum sampling window, the FOC control strategy is executed.

[0018] In a second aspect, an embodiment of the present invention provides a motor control device, which is applied to a PMSM based on a single resistor FOC, and the device includes:

[0019] A detection module, used for detecting a time window of a non-zero voltage vector action during a space vector modulation phase of the PMSM;

[0020] A judging module, used to judge whether the time window satisfies a preset minimum sampling window;

[0021] An updating module is used to update the non-zero voltage vector duty cycle of the space vector modulation stage when the time window meets the preset minimum sampling window.

[0022] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the motor control method as described in any one of the first aspects.

[0023] In a fourth aspect, an embodiment of the present invention provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of the motor control method as described in any one of the first aspects are implemented.

[0024] The technical solution of the embodiment of the present invention can reduce the motor working noise caused by single-resistance FOC phase shifting, while also reducing costs and improving motor control effects by detecting the time window of action of a non-zero voltage vector in the space vector modulation stage of a PMSM; and updating the non-zero voltage vector duty cycle in the space vector modulation stage according to whether the time window satisfies the minimum sampling window. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0026] Figure 1 is a FOC vector control diagram of a motor control method in one embodiment of the present invention;

[0027] Figure 2a This is a waveform diagram of the PWM phase shift before the first sector low voltage modulation area in one embodiment of the present invention;

[0028] Figure 2b This is a waveform diagram of the PWM phase shifted in the first sector low voltage modulation area in one embodiment of the present invention.

[0029] Figure 3 is a flow chart of a motor control method in one embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The terms "first", "second" etc. in the embodiments of the present invention are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. In addition, the terms "include" and "have" and any variation thereof are intended to cover non-exclusive inclusions, for example, the process, method, system, product or equipment comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment. In addition, "and / or" is used in the present application to represent at least one of the connected objects, such as A and / or B and / or C, which represents 7 situations including single A, single B, single C, and A and B all exist, B and C all exist, A and C all exist, and A, B and C all exist.

[0032] An embodiment of the present invention provides a motor control method.

[0033] The motor control method of the embodiment of the present invention is applied to a permanent magnet synchronous motor (PMSM) based on single resistor field oriented control (FOC).

[0034] like Figure 1 As shown, Figure 1 A typical FOC vector control diagram of a PMSM is shown. The method includes six steps from Step#1 to Step#6.

[0035] Step #1, obtain the current IA, IB and IC of each phase of the PMSM.

[0036] Step #2, perform Clark transformation and Park transformation on the obtained currents IA, IB and IC of each phase.

[0037] Step #3, estimate the rotor position and rotor speed based on the transformation results.

[0038] In Step #4 and Step #5, proportional control and integral control are performed based on the estimated results.

[0039] Step #6, perform inverse Park transform and space vector modulation (SVPWM), and output control voltages UA, UB and UC to each phase of the PMSM according to the modulation results.

[0040] The traditional single-resistor FOC solution has high noise, especially electromagnetic noise at medium and low speeds, which is caused by its phase shift strategy.

[0041] The phase shift strategy method acts on the SVPWM part of Step #6 of the vector control diagram. Its essence is to expand the time window of non-zero voltage vector action to ensure that they are not less than the minimum sampling time Tmin.

[0042] In the non-observation area, the phase shift method will modify the modulation mode of SVPWM and adopt an asymmetric PWM output mode to ensure that the PWM waveform has enough sampling time in the second half of the cycle.

[0043] like Figure 2a As shown, during the vector synthesis in the low-voltage modulation area of ​​the first sector, the action times T1 and T2 of vectors V110 and V100 are too short and phase shifting is required.

[0044] like Figure 2b As shown, during implementation, PWM3H with the smallest duty cycle is shifted to the left by Δt1, and PWM1H with the largest duty cycle is shifted to the right by Δt2, thereby widening the action time of V110 and V100 in the second half of PWM, leaving enough time for ADC sampling.

[0045] Such a phase shift strategy will cause a △u between the real voltage and the Vs calculated by the FOC vector control block diagram, thus causing noise. Here, the variable Vs is the vector sum of the dq axis voltages Ud and Uq in Step #5, and its magnitude can be obtained by taking the square root of the sum of the squares of the two.

[0046] The present invention provides a motor control method, which is applied to a permanent magnet synchronous motor (PMSM) based on single-resistance field oriented control (FOC).

[0047] In one embodiment, the method comprises the following steps:

[0048] During the space vector modulation phase of the PMSM, detecting a time window in which a non-zero voltage vector acts;

[0049] Determine whether the time window meets the preset minimum sampling window;

[0050] When the time window satisfies a preset minimum sampling window, the non-zero voltage vector duty cycle of the space vector modulation stage is updated.

[0051] In the technical solution of this embodiment, in the space vector modulation stage, that is, Figure 1 The SVPWM of the illustrated embodiment detects the time window T of the non-zero voltage vector. After the time window T is determined, it is further determined whether the time window T satisfies the preset minimum sampling window Tmin.

[0052] When the time window T meets the preset minimum sampling window Tmin, that is, when the time window T is greater than the preset minimum sampling window Tmin, it is necessary to update the non-zero voltage vector duty cycle of the space vector modulation stage to meet the sampling requirements and avoid the noise generated by the original phase shift operation.

[0053] In some embodiments, before updating the non-zero voltage vector duty cycle in the space vector modulation stage, the method further includes:

[0054] Record the cumulative number of times that the time window does not meet the preset minimum sampling window;

[0055] When the accumulated number of times is less than a preset threshold, the non-zero voltage vector duty cycle in the space vector modulation stage is maintained.

[0056] In the technical solution of this embodiment, if it is detected that a time window T does not satisfy the preset minimum sampling window Tmin, the update record is not immediately executed, but recorded and maintained.

[0057] In some embodiments, updating the non-zero voltage vector duty cycle in the space vector modulation stage includes:

[0058] When the accumulated number reaches a preset threshold, the non-zero voltage vector duty cycle in the space vector modulation stage is updated.

[0059] When the recorded times do not meet the preset cumulative times, the original recording control mode is maintained. When the recorded times reach the preset cumulative times, the update operation is performed.

[0060] In this way, the effectiveness of current sampling can be guaranteed to prevent sudden changes, while the frequency of noise can be reduced, thereby improving the control effect on the motor.

[0061] In some embodiments, updating the non-zero voltage vector duty cycle in the space vector modulation stage includes:

[0062] The time window of the non-zero voltage vector action is expanded so that the time window of the non-zero voltage vector action is not less than the minimum sampling time.

[0063] like Figure 3 As shown, the technical solution of this embodiment can be summarized as follows: after the vector PWM waveform comes out, it is first determined whether the time window T satisfies the minimum sampling window Tmin.

[0064] If it is satisfied, there is no need for phase shifting, the SVPWM duty cycle is updated, and the FOC operation continues; if it is not satisfied, the number of times that the time window T does not meet the minimum sampling window Tmin is counted. In this embodiment, the preset cumulative number of 5 is used as an example. When the cumulative number n is less than 5 times, the flag DelayFlag = 0, and the calculation of Step#2 and Step#6 in the FOC block diagram is not performed, and the previous operating state is maintained.

[0065] When the cumulative number n reaches 5 times, the flag DelayFlag = 1, no phase shift is required, the SVPWM duty cycle is updated, and the FOC block diagram operation continues.

[0066] In some embodiments, the method further comprises:

[0067] When the time window meets the preset minimum sampling window, the FOC control strategy is executed.

[0068] It can be understood that, when the time window T satisfies the preset minimum sampling window Tmin, the time window T can meet the sampling requirement. At this time, the original FOC control strategy can still be referred to for execution.

[0069] The embodiment of the present invention further provides a motor control device, which is applied to a PMSM based on a single resistor FOC, and the device includes:

[0070] A detection module, used for detecting a time window of a non-zero voltage vector action during a space vector modulation phase of the PMSM;

[0071] A judging module, used to judge whether the time window satisfies a preset minimum sampling window;

[0072] An updating module is used to update the non-zero voltage vector duty cycle of the space vector modulation stage when the time window meets the preset minimum sampling window.

[0073] In some embodiments, it also includes:

[0074] A recording module, used to record the cumulative number of times the time window does not meet the preset minimum sampling window;

[0075] The maintaining module is used to maintain the non-zero voltage vector duty cycle in the space vector modulation stage when the accumulated number of times is less than a preset threshold.

[0076] In some embodiments, the update module is specifically used to:

[0077] When the accumulated number reaches a preset threshold, the non-zero voltage vector duty cycle in the space vector modulation stage is updated.

[0078] In some embodiments, the update module is specifically used to:

[0079] The time window of the non-zero voltage vector action is expanded so that the time window of the non-zero voltage vector action is not less than the minimum sampling time.

[0080] In some embodiments, it also includes:

[0081] The execution module is used to execute the FOC control strategy when the time window meets the preset minimum sampling window.

[0082] The motor control device of the embodiment of the present invention can implement each step of the above-mentioned motor control method embodiment and can achieve the same or similar technical effects, which will not be described in detail here.

[0083] An embodiment of the present application also provides an electronic device, including a processor, a memory, and a program or instruction stored in the memory and executable on the processor. When the program or instruction is executed by the processor, each process of the above-mentioned method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0084] It should be noted that the electronic devices in the embodiments of the present application include the mobile electronic devices and non-mobile electronic devices mentioned above.

[0085] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0086] The processor is a processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0087] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0088] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0089] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A motor control method, applied to a permanent magnet synchronous motor PMSM based on single resistor field oriented control FOC, characterized in that: The method comprises the following steps: During the space vector modulation phase of the PMSM, detecting a time window in which a non-zero voltage vector acts; Determine whether the time window meets the preset minimum sampling window; When the time window satisfies a preset minimum sampling window, the non-zero voltage vector duty cycle of the space vector modulation stage is updated.

2. The method according to claim 1, characterized in that Before updating the non-zero voltage vector duty cycle in the space vector modulation stage, the method further includes: Record the cumulative number of times that the time window does not meet the preset minimum sampling window; When the accumulated number of times is less than a preset threshold, the non-zero voltage vector duty cycle in the space vector modulation stage is maintained.

3. The method according to claim 2, characterized in that The updating of the non-zero voltage vector duty cycle in the space vector modulation stage comprises: When the accumulated number reaches a preset threshold, the non-zero voltage vector duty cycle in the space vector modulation stage is updated.

4. The method according to claim 4, characterized in that The updating of the non-zero voltage vector duty cycle in the space vector modulation stage comprises: The time window of the non-zero voltage vector action is expanded so that the time window of the non-zero voltage vector action is not less than the minimum sampling time.

5. The method according to any one of claims 1 to 4, characterized in that The method further comprises: When the time window meets the preset minimum sampling window, the FOC control strategy is executed.

6. A motor control device, applied to a PMSM based on a single resistor FOC, characterized in that: The device comprises: A detection module, used for detecting a time window of a non-zero voltage vector action during a space vector modulation phase of the PMSM; A judging module, used to judge whether the time window satisfies a preset minimum sampling window; An updating module is used to update the non-zero voltage vector duty cycle of the space vector modulation stage when the time window meets the preset minimum sampling window.

7. An electronic device, characterized in that: It comprises a processor, a memory and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the motor control method as described in any one of claims 1 to 5.

8. A readable storage medium, characterized in that: The readable storage medium stores a program or instruction, and when the program or instruction is executed by a processor, the steps of the motor control method according to any one of claims 1 to 5 are implemented.

Images