Control method and device of permanent magnet synchronous motor, control equipment and storage medium

Abstract

The invention is suitable for the technical field of motors, and provides a control method and device of a permanent magnet synchronous motor, control equipment and a storage medium. The control method of the permanent magnet synchronous motor is applied to control equipment of the permanent magnet synchronous motor, and the control equipment is connected with an expansion state observer. The control method of the permanent magnet synchronous motor comprises the following steps: after the permanent magnet synchronous motor enters a constant-speed operation state, inputting a two-phase static current value and a two-phase static voltage value of the permanent magnet synchronous motor into an extended state observer, and obtaining a back electromotive force and a rotor flux linkage output by the extended state observer; according to the back electromotive force and the rotor flux linkage, determining the observation rotating speed and the rotor position of the permanent magnet synchronous motor; and determining whether the rotating speed of the permanent magnet synchronous motor is stable according to the observed rotating speed, and performing vector control on the permanent magnet synchronous motor according to the observed rotating speed and the rotor position after determining that the rotating speed of the permanent magnet synchronous motor is stable. Through the control method provided by the embodiment of the invention, the rotor position of the permanent magnet synchronous motor can be accurately determined, vector control can be accurately performed on the permanent magnet synchronous motor, and the control accuracy of the permanent magnet synchronous motor is improved.

Description

Technical Field

[0001] The present application belongs to the field of motor technology, and in particular, relates to a control method, device, control equipment and storage medium for a permanent magnet synchronous motor. Background Art

[0002] With the increasing application of new energy electric vehicles, the demand for high-quality control of permanent magnet synchronous motors is increasing.

[0003] At present, a permanent magnet synchronous motor is usually controlled by outputting three high and low level waveforms with a phase difference of 120 degrees in each electrical angle cycle of a three-phase mounted latch type Hall sensor.

[0004] However, only six 60-degree electrical angle regions can be obtained through these three high and low level waveforms, and the existing electrical angle estimation methods all rely on the speed calculated in the previous angle interval. Therefore, the delay is relatively large and the estimated angle error is large at low speed, high carrier ratio and rapid speed changes. The above problems lead to the low control accuracy of existing permanent magnet synchronous motors. Summary of the invention

[0005] In view of this, the embodiments of the present application provide a control method, device and storage medium for a permanent magnet synchronous motor to solve the technical problem of low control accuracy of existing permanent magnet synchronous motors.

[0006] In a first aspect, an embodiment of the present application provides a control method for a permanent magnet synchronous motor, which is applied to a control device of the permanent magnet synchronous motor, wherein the control device is connected to an extended state observer; the control method for the permanent magnet synchronous motor comprises: After the permanent magnet synchronous motor enters a constant speed running state, inputting two-phase static current values ​​and two-phase static voltage values ​​of the permanent magnet synchronous motor into the extended state observer, and obtaining back electromotive force and rotor flux output by the extended state observer; Determining the observed speed and rotor position of the permanent magnet synchronous motor according to the back electromotive force and the rotor flux; According to the observed rotational speed, it is determined whether the rotational speed of the permanent magnet synchronous motor is stable. After determining that the rotational speed of the permanent magnet synchronous motor is stable, vector control is performed on the permanent magnet synchronous motor according to the observed rotational speed and the rotor position.

[0007] Optionally, before the permanent magnet synchronous motor enters the constant speed running state, the method further includes: When the permanent magnet synchronous motor is stationary, the permanent magnet synchronous motor is controlled to rotate with a preset dq-axis current through a preset current-to-frequency ratio control strategy until the permanent magnet synchronous motor enters the constant speed operation state.

[0008] Optionally, controlling the rotation of the permanent magnet synchronous motor with a preset dq axis current by using a preset current-to-frequency ratio control strategy includes: Controlling the rotor of the permanent magnet synchronous motor to rotate to a target angle according to the dq-axis current; Controlling the rotor of the permanent magnet synchronous motor to accelerate and rotate at a preset acceleration; After the rotation speed of the rotor of the permanent magnet synchronous motor reaches a preset rotation speed, the rotor of the permanent magnet synchronous motor is controlled to rotate at a constant speed at the preset rotation speed, so that the permanent magnet synchronous motor enters the constant speed operation state.

[0009] Optionally, determining whether the speed of the permanent magnet synchronous motor is stable according to the observed speed includes: Obtaining a preset deviation coefficient and a preset duration threshold; Determining a target speed range according to the preset speed and the deviation coefficient; If the duration that the observed speed is within the target speed range is greater than the duration threshold, it is determined that the speed of the permanent magnet synchronous motor is stable.

[0010] Optionally, the control device is also connected to the current loop; the two-phase static current value and the two-phase static voltage value are determined by: Acquire the three-phase current value of the permanent magnet synchronous motor, and convert the three-phase current value into the two-phase static current value; The two-phase static current value is used as the current input of the extended state observer, and two voltage components of the dq coordinate system output by the current loop are obtained, and the two voltage components are converted into the two-phase static voltage value.

[0011] Optionally, after acquiring the back electromotive force and rotor flux output by the extended state observer, the method further includes: Determine the air gap flux in the αβ coordinate system according to the rotor flux; According to the integrated rotor flux and a preset current model formula, the air gap flux in the αβ coordinate system is transformed into the air gap flux in the dq coordinate system; After subtracting the preset rotor flux constant from the air gap flux in the dq coordinate system, a first current component in the α coordinate system and a second current component in the β coordinate system are obtained by inverse transformation; Determining a first correction compensation item in an α coordinate system and a second correction compensation item in a β coordinate system according to the first current component and the second current component; The back electromotive force is corrected according to the first correction compensation term and the second correction compensation term.

[0012] Optionally, determining the observed speed and rotor position of the permanent magnet synchronous motor according to the back electromotive force and the rotor flux includes: An orthogonal phase-locked loop structure is constructed according to the back electromotive force and the rotor flux, and the observed rotation speed and the rotor position are determined according to the orthogonal phase-locked loop structure.

[0013] In a second aspect, an embodiment of the present application provides a control device for a permanent magnet synchronous motor, which is applied to a control device for a permanent magnet synchronous motor, wherein the control device is connected to an extended state observer; the control device for the permanent magnet synchronous motor includes: a data acquisition unit, configured to input two-phase static current values ​​and two-phase static voltage values ​​of the permanent magnet synchronous motor into the extended state observer after the permanent magnet synchronous motor enters a constant speed operation state, and to acquire back electromotive force and rotor flux output by the extended state observer; A data determination unit, configured to determine an observed speed and a rotor position of the permanent magnet synchronous motor according to the back electromotive force and the rotor flux; A control unit is used to determine whether the speed of the permanent magnet synchronous motor is stable according to the observed speed, and after determining that the speed of the permanent magnet synchronous motor is stable, perform vector control on the permanent magnet synchronous motor according to the observed speed and the rotor position.

[0014] In a third aspect, an embodiment of the present application provides a control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, each step in the control method of a permanent magnet synchronous motor as described in any one of the first aspects above is implemented.

[0015] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, each step in the control method of a permanent magnet synchronous motor as described in any one of the above-mentioned first aspects is implemented.

[0016] In a fifth aspect, an embodiment of the present application provides a computer program product. When the computer program product runs on a control device, the control device executes each step in the control method of a permanent magnet synchronous motor as described in any one of the first aspects above.

[0017] The control method, device and storage medium of the permanent magnet synchronous motor provided by the embodiments of the present application have the following beneficial effects: In the control method of the permanent magnet synchronous motor provided in the embodiment of the present application, after the permanent magnet synchronous motor enters the constant speed running state, the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor are input into the extended state observer, and the back electromotive force and the rotor flux output by the extended state observer are obtained; according to the back electromotive force and the rotor flux, the observed speed and the rotor position of the permanent magnet synchronous motor are determined; according to the observed speed, it is determined whether the speed of the permanent magnet synchronous motor is stable, and after determining that the speed of the permanent magnet synchronous motor is stable, the permanent magnet synchronous motor is vector controlled according to the observed speed and the rotor position. Through the control method provided in the embodiment of the present application, the rotor position of the permanent magnet synchronous motor can be accurately determined, and then the permanent magnet synchronous motor can be accurately vector controlled, thereby improving the control accuracy of the permanent magnet synchronous motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 A flowchart of a control method for a permanent magnet synchronous motor provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of a control device for a permanent magnet synchronous motor provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of a control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0020] It should be noted that the terms used in the embodiments of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. In the description of the embodiments of the present application, unless otherwise specified, "multiple" refers to two or more than two, and "at least one", "one or more" refers to one, two or more. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, it is defined that the "first" and "second" features can explicitly or implicitly include one or more of the features.

[0021] References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0022] The control method of the permanent magnet synchronous motor provided in the embodiment of the present application can be applied to the control device of the permanent magnet synchronous motor.

[0023] The control method of the permanent magnet synchronous motor provided in the embodiment of the present application can be applied to various scenarios where the permanent magnet synchronous motor needs to be controlled. Specifically, when the permanent magnet synchronous motor needs to be controlled, the various steps of the control method of the permanent magnet synchronous motor provided in the embodiment of the present application can be executed by a control device including an extended state observer, so that the control device can accurately determine the rotor position of the permanent magnet synchronous motor, and then accurately perform vector control on the permanent magnet synchronous motor.

[0024] See also Figure 1 , Figure 1 A flow chart for implementing a control method for a permanent magnet synchronous motor provided in an embodiment of the present application. The control method for a permanent magnet synchronous motor can be applied to a control device of a permanent magnet synchronous motor, wherein the control device of the permanent magnet synchronous motor can be connected to an extended state observer. The control method for a permanent magnet synchronous motor provided in an embodiment of the present application may include S101 to S103, which are described in detail as follows: In S101, after the permanent magnet synchronous motor enters the constant speed running state, the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor are input into the extended state observer, and the back electromotive force and the rotor flux output by the extended state observer are obtained.

[0025] In an embodiment of the present application, the control device can control the rotation of the permanent magnet synchronous motor with a preset dq-axis current through a preset current-frequency ratio control strategy (IF control strategy) when the permanent magnet synchronous motor is stationary, until the permanent magnet synchronous motor enters a constant speed operation state, thereby enabling the permanent magnet synchronous motor to enter a constant speed operation state.

[0026] Specifically, the control device can realize the control of the permanent magnet synchronous motor rotation by using the preset dq axis current through the preset current-to-frequency ratio control strategy through steps a to c. The details are as follows: In step a, the rotor of the permanent magnet synchronous motor is controlled to rotate to a target angle according to the dq axis current.

[0027] In this implementation, the control device can control the rotor of the permanent magnet synchronous motor to rotate to a target angle according to the preset dq axis current.

[0028] Step a is the rotor pre-positioning stage in the flow-frequency ratio control strategy. In this stage, the initial position of the rotor of the permanent magnet synchronous motor is uncertain, but since the d-axis direction of the dq-axis coordinate system on the rotor is always along the direction of the rotor magnetic flux, in practical applications, the d-axis current can be given as 0 in the virtual dq-axis coordinate system in the flow-frequency ratio control strategy, and the q-axis current can be given as a preset constant in the virtual dq-axis coordinate system in the flow-frequency ratio control strategy. The generated electromagnetic torque rotates the rotor of the permanent magnet synchronous motor to a known target angle, thereby achieving rotor pre-positioning. At this time, the difference angle between the virtual dq-axis coordinate system and the real dq-axis coordinate system is 90 degrees.

[0029] In step b, the rotor of the permanent magnet synchronous motor is controlled to accelerate and rotate at a fixed acceleration.

[0030] In this implementation, after controlling the rotor of the permanent magnet synchronous motor to rotate to the target angle, the control device may control the rotor of the permanent magnet synchronous motor to accelerate the rotation at a fixed acceleration, wherein the fixed acceleration may be set according to actual needs.

[0031] Step b is the constant acceleration acceleration stage in the flow-frequency ratio control strategy. In this stage, the control device can increase the angle based on the target angle determined in step a, and the difference angle between the virtual dq-axis coordinate system and the real dq-axis coordinate system will decrease. According to the torque-power angle self-balancing principle, the electromagnetic torque gradually increases until the rotor of the permanent magnet synchronous motor overcomes the load and viscous friction, and the rotor of the permanent magnet synchronous motor will start to rotate synchronously.

[0032] In practical applications, during the constant acceleration stage, the speed calculation formula, electromagnetic torque formula and torque balance equation given below can be used.

[0033] The speed calculation formula can be:

[0034] in, is the angular velocity, They are the self-increment angle and FOC operation interruption time respectively.

[0035] The electromagnetic torque formula can be: =1.5 . cosθref in, is the motor electromagnetic torque, is the number of motor pole pairs, is the motor rotor flux, is the q-axis current given in the virtual dq-axis coordinate system, and is the difference angle between the virtual dq-axis coordinate system and the real dq-axis coordinate system.

[0036] The torque balance equation can be:

[0037] in, is the motor electromagnetic torque, is the load torque, is the motor mechanical angular velocity.

[0038] In step c, after the rotation speed of the rotor of the permanent magnet synchronous motor reaches a preset rotation speed, the rotor of the permanent magnet synchronous motor is controlled to rotate at a constant speed at the preset rotation speed.

[0039] Since the observation angle of the expanded state observer is constantly approaching the precise angle as the speed of the permanent magnet synchronous motor's rotor increases, after the speed of the permanent magnet synchronous motor's rotor reaches a preset speed, it can be considered that the observation angle of the expanded state observer is relatively accurate. At this time, the permanent magnet synchronous motor's rotor can be controlled to rotate at a preset speed, so that the permanent magnet synchronous motor can enter a constant speed operation state. The preset speed can be set according to actual needs and is not limited here.

[0040] After determining that the permanent magnet synchronous motor enters the constant speed operation state, the control device can control the permanent magnet synchronous motor through the extended state observer.

[0041] Specifically, in the process of controlling the rotation of the permanent magnet synchronous motor, the control device can obtain the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor in real time. After determining that the permanent magnet synchronous motor enters the constant speed operation state, the control device can input the current two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor into the extended state observer, thereby obtaining the back electromotive force and the rotor flux from the extended state observer.

[0042] In a possible implementation, the control device may obtain the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor through steps d to e, as described in detail as follows: In step d, the three-phase current values ​​of the permanent magnet synchronous motor are obtained, and the three-phase current values ​​are converted into two-phase static current values.

[0043] In this implementation, the control device can obtain the three-phase current value of the permanent magnet synchronous motor through the current value acquisition device, and then convert the three-phase current value into a two-phase static current value through a first preset transformation. Wherein, as an example but not a limitation, the first preset transformation can be a Clark transformation.

[0044] In step e, the two-phase static current values ​​are used as current inputs of the extended state observer, and two voltage components of the dq coordinate system of the current loop output are obtained, and the two voltage components are converted into two-phase static voltage values.

[0045] In this implementation, after obtaining the two-phase static current value of the permanent magnet synchronous motor, the control device can use the two-phase static current value as the current input of the extended state observer. After using the two-phase static current value as the current input of the extended state observer, the current loop connected to the control device will output two voltage components of the dq coordinate system. Based on this, the control device can obtain the two voltage components of the dq coordinate system output by the current loop, and convert the two voltage components into two-phase static voltage values ​​through a second preset transformation, so that the control device can obtain the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor. Wherein, as an example but not a limitation, the second preset transformation can be a Park transformation.

[0046] After obtaining the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor, the control device can input the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor into the extended state observer, so as to obtain the back electromotive force and rotor flux output by the extended state observer.

[0047] In S102, the observed speed and rotor position of the permanent magnet synchronous motor are determined according to the back electromotive force and the rotor flux.

[0048] Since the back EMF output by the traditional extended state observer is affected by parameter mismatch, DC component and high-frequency noise, the αβ-axis back EMF waveform has a relatively large jitter, which in turn causes severe jitter in the observed speed and a relatively large observation angle error. Although the high-frequency noise can be suppressed by inputting the rotor flux obtained by integrating the back EMF into the phase-locked loop, the DC component in the back EMF will also cause a DC bias.

[0049] Based on this, in the embodiment of the present application, after the control device obtains the back electromotive force and the rotor flux output by the extended state observer, the back electromotive force can be corrected through steps f to j, as described in detail as follows: In step f, the air gap flux in the αβ coordinate system is determined based on the rotor flux.

[0050] In this implementation, the control device can determine the air gap flux in the αβ coordinate system according to the rotor flux output by the extended state observer. The specific determination method can be set according to actual needs and is not limited here.

[0051] In step g, the air gap flux in the αβ coordinate system is transformed into the air gap flux in the dq coordinate system according to the integrated rotor flux and the preset current model formula.

[0052] In this implementation, after determining the air gap flux of the αβ coordinate system, the control device can transform the obtained air gap flux of the αβ coordinate system into the air gap flux of the dq coordinate system through a preset third transformation according to the integrated rotor flux and the preset current model formula. Wherein, as an example but not a limitation, the third preset transformation can be a Park transformation.

[0053] In step h, after subtracting the preset rotor flux constant from the air gap flux in the dq coordinate system, an inverse transformation is performed to obtain a first current component in the α coordinate system and a second current component in the β coordinate system.

[0054] In this implementation, after the air gap flux in the dq coordinate system is transformed, the control device can subtract a preset rotor flux constant from the obtained air gap flux in the dq coordinate system, and then transform the result of subtracting the preset rotor flux constant from the air gap flux in the dq coordinate system through a reverse preset third transformation to obtain the first current component in the α coordinate system and the second current component in the β coordinate system.

[0055] In step i, a first correction compensation term in the α coordinate system and a second correction compensation term in the β coordinate system are determined according to the first current component and the second current component.

[0056] In this implementation, after obtaining the first current component and the second current component, the control device may determine a first correction compensation item in the α coordinate system and a second correction compensation item in the β coordinate system according to the first current component and the second current component.

[0057] Since the obtained first current component and the second current component are the observation values ​​of the expanded state observer, and the two current components included in the two-phase static current value previously input into the expanded state observer are actual values, the deviation value can be calculated based on the obtained first current component and the second current component, and the two-phase static current value, and then the first correction compensation item in the α coordinate system and the second correction compensation item in the β coordinate system can be obtained according to the deviation value.

[0058] Exemplarily, the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system may be determined according to the first current component and the second current component by the following formula:

[0059] in, is the air gap flux component in the α coordinate system, is the air gap flux component in the β coordinate system, is the inductance in the α coordinate system, is the inductance in the β coordinate system, is the first current component in the α coordinate system, is the second current component in the β coordinate system, is the rotor flux component in the α coordinate system, is the rotor flux component in the β coordinate system.

[0060] In the above formula, , It can be determined by the air gap flux linkage of the αβ coordinate system obtained by the control device, and It can be obtained by measurement, so it can be obtained by the above formula and , and then according to the obtained and A first correction compensation item in the α coordinate system and a second correction compensation item in the β coordinate system are determined.

[0061] In step j, the back electromotive force is corrected according to the first correction compensation term and the second correction compensation term.

[0062] In this implementation, after obtaining the first correction compensation item in the α coordinate system and the second correction compensation item in the β coordinate system, the control device can compensate for the parameter mismatch item and DC component in the back electromotive force according to the first correction compensation item and the second correction compensation item, thereby correcting the back electromotive force.

[0063] After the back electromotive force is corrected, the control device can determine the rotor position of the permanent magnet synchronous motor according to the corrected back electromotive force and the rotor flux.

[0064] Exemplarily, the control device may construct an orthogonal phase-locked loop structure according to the corrected back electromotive force and rotor flux through the following formula.

[0065] - =

[0066] in, is the rotor flux difference, Estimated rotor position for the extended state observer.

[0067] After the orthogonal phase-locked loop structure is obtained, the control device can determine the observed speed and rotor position of the permanent magnet synchronous motor according to the orthogonal phase-locked loop structure.

[0068] In S103, it is determined whether the speed of the permanent magnet synchronous motor is stable according to the observed speed. After it is determined that the speed of the permanent magnet synchronous motor is stable, vector control is performed on the permanent magnet synchronous motor according to the observed speed and the rotor position.

[0069] After determining the observed speed, the control device can determine whether the speed of the permanent magnet synchronous motor is stable according to the observed speed. Specifically, the control device can determine whether the speed of the permanent magnet synchronous motor is stable in the following manner: First, the control device can obtain a preset deviation coefficient and a preset duration threshold, wherein the preset deviation coefficient and the preset duration threshold can be set according to actual needs. After obtaining the deviation coefficient and the duration threshold, the control device can determine the target speed range according to the preset speed and deviation coefficient of the permanent magnet synchronous motor. After that, the control device can determine whether the observed speed of the permanent magnet synchronous motor is within the target speed range. If it is determined that the duration of the observed speed of the permanent magnet synchronous motor in the target speed range is greater than the duration threshold, the control device can determine that the speed of the permanent magnet synchronous motor is stable.

[0070] In practical applications, the specific values ​​of the preset deviation coefficient and the preset duration threshold can be adjusted to achieve smooth switching from the flow-to-frequency ratio control strategy to the extended state observer control strategy.

[0071] After determining that the speed of the permanent magnet synchronous motor is stable, the control device can perform vector control on the permanent magnet synchronous motor based on the observed speed and rotor position.

[0072] It can be seen from the above that in the control method of the permanent magnet synchronous motor provided in the embodiment of the present application, after the permanent magnet synchronous motor enters the constant speed running state, the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor are input into the extended state observer, and the back electromotive force and the rotor flux output by the extended state observer are obtained; according to the back electromotive force and the rotor flux, the observed speed and the rotor position of the permanent magnet synchronous motor are determined; according to the observed speed, it is determined whether the speed of the permanent magnet synchronous motor is stable, and after determining that the speed of the permanent magnet synchronous motor is stable, the permanent magnet synchronous motor is vector controlled according to the observed speed and the rotor position. Through the control method provided in the embodiment of the present application, the rotor position of the permanent magnet synchronous motor can be accurately determined, and then the permanent magnet synchronous motor can be accurately vector controlled, thereby improving the control accuracy of the permanent magnet synchronous motor.

[0073] Based on the control method of the permanent magnet synchronous motor provided in the above embodiment, the present application further provides a control device for the permanent magnet synchronous motor that implements the above method embodiment. Figure 2 , Figure 2 The structure diagram of a control device for a permanent magnet synchronous motor provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the control device 20 of the permanent magnet synchronous motor may include: a data acquisition unit 21, a data determination unit 22 and a control unit 23. Among them: The data acquisition unit 21 is used to input the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor into the extended state observer after the permanent magnet synchronous motor enters the constant speed operation state, and obtain the back electromotive force and rotor flux output by the extended state observer.

[0074] The data determination unit 22 is used to determine the observed speed and rotor position of the permanent magnet synchronous motor according to the back electromotive force and the rotor flux.

[0075] The control unit 23 is used to determine whether the speed of the permanent magnet synchronous motor is stable according to the observed speed, and after determining that the speed of the permanent magnet synchronous motor is stable, perform vector control on the permanent magnet synchronous motor according to the observed speed and the rotor position.

[0076] Optionally, the control device 20 of the permanent magnet synchronous motor may further include a current-frequency ratio strategy control unit, wherein: The flow-frequency ratio policy control unit is used to: When the permanent magnet synchronous motor is stationary, the permanent magnet synchronous motor is controlled to rotate with a preset dq-axis current through a preset current-to-frequency ratio control strategy until the permanent magnet synchronous motor enters the constant speed operation state.

[0077] Optionally, the flow-frequency ratio policy control unit is specifically used for: Controlling the rotor of the permanent magnet synchronous motor to rotate to a target angle according to the dq-axis current; Controlling the rotor of the permanent magnet synchronous motor to accelerate and rotate at a preset acceleration; After the rotation speed of the rotor of the permanent magnet synchronous motor reaches a preset rotation speed, the rotor of the permanent magnet synchronous motor is controlled to rotate at a constant speed at the preset rotation speed, so that the permanent magnet synchronous motor enters the constant speed operation state.

[0078] Optionally, the control unit 23 is specifically configured to: Obtaining a preset deviation coefficient and a preset duration threshold; Determining a target speed range according to the preset speed and the deviation coefficient; If the duration that the observed speed is within the target speed range is greater than the duration threshold, it is determined that the speed of the permanent magnet synchronous motor is stable.

[0079] Optionally, the data acquisition unit may be further configured to: Acquire the three-phase current value of the permanent magnet synchronous motor, and convert the three-phase current value into the two-phase static current value; The two-phase static current value is used as the current input of the extended state observer, and two voltage components of the dq coordinate system output by the current loop are obtained, and the two voltage components are converted into the two-phase static voltage value.

[0080] Optionally, the control device 20 of the permanent magnet synchronous motor may further include a correction unit, wherein: The correction unit is specifically used for: According to the rotor flux, determine the air gap flux in the αβ coordinate system; According to the integrated rotor flux and the preset current model formula, the air gap flux in the αβ coordinate system is transformed into the air gap flux in the dq coordinate system; After subtracting the preset rotor flux constant from the air gap flux in the dq coordinate system, the first current component in the α coordinate system and the second current component in the β coordinate system are obtained by inverse transformation; Determining a first correction compensation item in an α coordinate system and a second correction compensation item in a β coordinate system according to the first current component and the second current component; The back electromotive force is corrected according to the first correction compensation term and the second correction compensation term.

[0081] Optionally, the control unit 23 is specifically configured to: An orthogonal phase-locked loop structure is constructed according to the back electromotive force and the rotor flux, and the observed rotation speed and the rotor position are determined according to the orthogonal phase-locked loop structure.

[0082] It should be noted that the information interaction, execution process and other contents between the above-mentioned units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be specifically referred to the method embodiment part and will not be repeated here.

[0083] See also Figure 3 , Figure 3 This is a schematic diagram of the structure of a control device provided in an embodiment of the present application. Figure 3As shown, the control device 3 provided in this embodiment may include: a processor 30, a memory 31, and a computer program 32 stored in the memory 31 and executable on the processor 30, such as a program corresponding to the control method of a permanent magnet synchronous motor. When the processor 30 executes the computer program 32, the steps in the control method embodiment applied to the permanent magnet synchronous motor are implemented, such as Figure 1 Alternatively, when the processor 30 executes the computer program 32, the functions of each module / unit in the above-mentioned control device for permanent magnet synchronous motor are realized, for example Figure 2 The functions of units 21 to 23 are shown.

[0084] Exemplarily, the computer program 32 may be divided into one or more modules / units, one or more modules / units are stored in the memory 31 and executed by the processor 30 to complete the present application. One or more modules / units may be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program 32 in the control device 3. For example, the computer program 32 may be divided into a data determination unit and a control unit. The specific functions of each unit can be referred to in Figure 2 The relevant descriptions in the corresponding embodiments are not repeated here.

[0085] Those skilled in the art will understand that Figure 3 This is only an example of the control device 3 and does not constitute a limitation on the control device 3 , which may include more or less components than shown in the figure, or a combination of certain components, or different components.

[0086] The processor 30 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0087] The memory 31 may be an internal storage unit of the control device 3, such as a hard disk or memory of the control device 3. The memory 31 may also be an external storage device of the control device 3, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, or a flash card, etc., equipped on the control device 3. Further, the memory 31 may also include both an internal storage unit and an external storage device of the control device 3. The memory 31 is used to store computer programs and other programs and data required by the control device. The memory 31 may also be used to temporarily store data that has been output or is to be output.

[0088] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units is used as an example. In practical applications, the above-mentioned function allocation can be completed by different functional units as needed, that is, the internal structure of the control device of the permanent magnet synchronous motor is divided into different functional units to complete all or part of the functions described above. The functional units in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the unit in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0089] An embodiment of the present application further provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0090] An embodiment of the present application provides a computer program product. When the computer program product is executed on a terminal device, the terminal device implements the steps in the above-mentioned various method embodiments.

[0091] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0092] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0093] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A control method for a permanent magnet synchronous motor, characterized in that: A control device applied to a permanent magnet synchronous motor, wherein the control device is connected to an extended state observer; and a control method for the permanent magnet synchronous motor comprises: After the permanent magnet synchronous motor enters a constant speed running state, inputting two-phase static current values ​​and two-phase static voltage values ​​of the permanent magnet synchronous motor into the extended state observer, and obtaining back electromotive force and rotor flux output by the extended state observer; Determining the observed speed and rotor position of the permanent magnet synchronous motor according to the back electromotive force and the rotor flux; According to the observed rotational speed, it is determined whether the rotational speed of the permanent magnet synchronous motor is stable. After determining that the rotational speed of the permanent magnet synchronous motor is stable, vector control is performed on the permanent magnet synchronous motor according to the observed rotational speed and the rotor position.

2. The method according to claim 1, characterized in that Before the permanent magnet synchronous motor enters the constant speed running state, the method further includes: When the permanent magnet synchronous motor is stationary, the permanent magnet synchronous motor is controlled to rotate with a preset dq-axis current through a preset current-to-frequency ratio control strategy until the permanent magnet synchronous motor enters the constant speed operation state.

3. The method according to claim 2, characterized in that The method of controlling the rotation of the permanent magnet synchronous motor with a preset dq axis current by using a preset current-to-frequency ratio control strategy comprises: Controlling the rotor of the permanent magnet synchronous motor to rotate to a target angle according to the dq-axis current; Controlling the rotor of the permanent magnet synchronous motor to accelerate and rotate at a preset acceleration; After the rotation speed of the rotor of the permanent magnet synchronous motor reaches a preset rotation speed, the rotor of the permanent magnet synchronous motor is controlled to rotate at a constant speed at the preset rotation speed, so that the permanent magnet synchronous motor enters the constant speed operation state.

4. The method according to claim 3, characterized in that Determining whether the speed of the permanent magnet synchronous motor is stable according to the observed speed includes: Obtaining a preset deviation coefficient and a preset duration threshold; Determining a target speed range according to the preset speed and the deviation coefficient; If the duration that the observed speed is within the target speed range is greater than the duration threshold, it is determined that the speed of the permanent magnet synchronous motor is stable.

5. The method according to claim 1, characterized in that The control device is also connected to the current loop; the two-phase static current value and the two-phase static voltage value are determined by: Acquire the three-phase current value of the permanent magnet synchronous motor, and convert the three-phase current value into the two-phase static current value; The two-phase static current value is used as the current input of the extended state observer, and two voltage components of the dq coordinate system output by the current loop are obtained, and the two voltage components are converted into the two-phase static voltage value.

6. The method according to claim 1, characterized in that After acquiring the back electromotive force and rotor flux output by the extended state observer, the method further includes: Determine the air gap flux in the αβ coordinate system according to the rotor flux; According to the integrated rotor flux and a preset current model formula, the air gap flux in the αβ coordinate system is transformed into the air gap flux in the dq coordinate system; After subtracting the preset rotor flux constant from the air gap flux in the dq coordinate system, a first current component in the α coordinate system and a second current component in the β coordinate system are obtained by inverse transformation; Determining a first correction compensation item in an α coordinate system and a second correction compensation item in a β coordinate system according to the first current component and the second current component; The back electromotive force is corrected according to the first correction compensation term and the second correction compensation term.

7. The method according to any one of claims 1 to 6, characterized in that: Determining the observed speed and rotor position of the permanent magnet synchronous motor according to the back electromotive force and the rotor flux includes: An orthogonal phase-locked loop structure is constructed according to the back electromotive force and the rotor flux, and the observed rotation speed and the rotor position are determined according to the orthogonal phase-locked loop structure.

8. A control device for a permanent magnet synchronous motor, characterized in that: A control device applied to a permanent magnet synchronous motor, wherein the control device is connected to an extended state observer; the control device of the permanent magnet synchronous motor comprises: a data acquisition unit, configured to input two-phase static current values ​​and two-phase static voltage values ​​of the permanent magnet synchronous motor into the extended state observer after the permanent magnet synchronous motor enters a constant speed operation state, and to acquire back electromotive force and rotor flux output by the extended state observer; A data determination unit, configured to determine an observed speed and a rotor position of the permanent magnet synchronous motor according to the back electromotive force and the rotor flux; A control unit is used to determine whether the speed of the permanent magnet synchronous motor is stable according to the observed speed, and after determining that the speed of the permanent magnet synchronous motor is stable, perform vector control on the permanent magnet synchronous motor according to the observed speed and the rotor position.

9. A control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, each step in the control method of the permanent magnet synchronous motor according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, each step of the control method of the permanent magnet synchronous motor as claimed in any one of claims 1 to 7 is implemented.

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