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

Abstract

The application is suitable for the technical field of electric machines, and provides a control method and device of a permanent magnet synchronous motor, a control equipment and a storage medium. The control method of the permanent magnet synchronous motor is applied to the control equipment of the permanent magnet synchronous motor, and the control equipment is connected with an extended 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 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 an observed rotating speed and a rotor position of the permanent magnet synchronous motor according to the back electromotive force and the rotor flux; determining whether the rotating speed of the permanent magnet synchronous motor is stable according to the observed rotating speed, and after determining that the rotating speed of the permanent magnet synchronous motor is stable, performing vector control on the permanent magnet synchronous motor according to the observed rotating speed and the rotor position. Through the control method provided in the application, the rotor position of the permanent magnet synchronous motor can be accurately determined, and then the vector control on the permanent magnet synchronous motor can be accurately performed, thereby improving the control accuracy of the permanent magnet synchronous motor.

Description

Technical Field

[0001] This 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 Technology

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

[0003] Currently, permanent magnet synchronous motors are typically controlled by outputting three high- and low-level waveforms with a phase difference of 120 degrees for each electrical angle cycle using a latching Hall sensor installed in three phases.

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

[0005] In view of this, embodiments of this 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, embodiments of this application provide a control method for a permanent magnet synchronous motor, applied to a control device for 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 includes:

[0007] After the permanent magnet synchronous motor enters the constant speed operation state, the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor are input to the extended state observer, and the back electromotive force and rotor flux output by the extended state observer are obtained.

[0008] Based on the back electromotive force and rotor flux linkage, the observed speed and rotor position of the permanent magnet synchronous motor are determined.

[0009] Based on 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 based on the observed rotational speed and the rotor position.

[0010] Optionally, before the permanent magnet synchronous motor enters the constant speed operation state, the following steps are also included:

[0011] When the permanent magnet synchronous motor is stationary, the motor is rotated by a preset current-frequency ratio control strategy with a preset dq axis current until the motor enters the constant speed operation state.

[0012] Optionally, controlling the rotation of the permanent magnet synchronous motor with a preset dq-axis current using a preset current-to-frequency ratio control strategy includes:

[0013] The rotor of the permanent magnet synchronous motor is controlled to rotate to the target angle based on the dq axis current;

[0014] The rotor of the permanent magnet synchronous motor is controlled to rotate at a preset acceleration.

[0015] After the rotor speed of the permanent magnet synchronous motor reaches the preset speed, the rotor of the permanent magnet synchronous motor is controlled to rotate at the preset speed to allow the permanent magnet synchronous motor to enter the constant speed operation state.

[0016] Optionally, determining whether the speed of the permanent magnet synchronous motor is stable based on the observed speed includes:

[0017] Obtain the preset deviation coefficient and the preset duration threshold;

[0018] The target speed range is determined based on the preset speed and the deviation coefficient;

[0019] If the duration for which the observed rotational speed is within the target rotational speed range is greater than the duration threshold, then the rotational speed of the permanent magnet synchronous motor is determined to be stable.

[0020] Optionally, the control device is also connected to a current loop; the two-phase quiescent current value and the two-phase quiescent voltage value are determined in the following manner:

[0021] Obtain the three-phase current values ​​of the permanent magnet synchronous motor and convert the three-phase current values ​​into the two-phase static current values;

[0022] The two-phase quiescent current values ​​are used as the current input of the extended state observer, and the two voltage components of the dq coordinate system output by the current loop are obtained and converted into the two-phase quiescent voltage values.

[0023] Optionally, after acquiring the back electromotive force and rotor flux output by the extended state observer, the method further includes:

[0024] Based on the rotor flux linkage, determine the air gap flux linkage in the αβ coordinate system;

[0025] Based on the integrated rotor flux linkage and the preset current model formula, the air gap flux linkage in the αβ coordinate system is transformed into the air gap flux linkage in the dq coordinate system.

[0026] 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.

[0027] Based on the first current component and the second current component, determine the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system;

[0028] The back electromotive force is corrected according to the first correction compensation term and the second correction compensation term.

[0029] Optionally, determining the observed speed and rotor position of the permanent magnet synchronous motor based on the back electromotive force and rotor flux linkage includes:

[0030] An orthogonal phase-locked loop structure is constructed based on the back electromotive force and the rotor flux linkage, and the observed rotational speed and the rotor position are determined based on the orthogonal phase-locked loop structure.

[0031] Secondly, embodiments of this application provide a control device for a permanent magnet synchronous motor, applied to a control equipment for a permanent magnet synchronous motor, wherein the control equipment is connected to an extended state observer; the control equipment for the permanent magnet synchronous motor includes:

[0032] The data acquisition unit is used to input the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor to the extended state observer after the permanent magnet synchronous motor enters the constant speed operation state, and to acquire the back electromotive force and rotor flux output by the extended state observer.

[0033] The data determination unit is used to determine the observed speed and rotor position of the permanent magnet synchronous motor based on the back electromotive force and rotor flux linkage.

[0034] The control unit is used to determine whether the speed of the permanent magnet synchronous motor is stable based on the observed speed. After determining that the speed of the permanent magnet synchronous motor is stable, the control unit performs vector control on the permanent magnet synchronous motor based on the observed speed and the rotor position.

[0035] Thirdly, embodiments of this application provide a control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the control method for a permanent magnet synchronous motor as described in any of the first aspects above.

[0036] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the control method for a permanent magnet synchronous motor as described in any of the first aspects above.

[0037] Fifthly, embodiments of this application provide a computer program product that, when run on a control device, causes the control device to execute the steps of the control method for a permanent magnet synchronous motor as described in any of the first aspects above.

[0038] The control method, apparatus, and storage medium for permanent magnet synchronous motors provided in this application have the following beneficial effects:

[0039] In the control method for a permanent magnet synchronous motor provided in this application embodiment, after the permanent magnet synchronous motor enters a constant-speed operation state, the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor are input to an extended state observer, and the back electromotive force and rotor flux linkage output by the extended state observer are obtained; based on the back electromotive force and rotor flux linkage, the observed speed and rotor position of the permanent magnet synchronous motor are determined; based on the observed speed, it is determined whether the speed of the permanent magnet synchronous motor is stable; after determining that the speed of the permanent magnet synchronous motor is stable, vector control is performed on the permanent magnet synchronous motor based on the observed speed and rotor position. Through the control method provided in this application embodiment, the rotor position of the permanent magnet synchronous motor can be accurately determined, thereby enabling accurate vector control of the permanent magnet synchronous motor and improving the control accuracy of the permanent magnet synchronous motor. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A flowchart illustrating the implementation of a control method for a permanent magnet synchronous motor provided in this application embodiment;

[0042] Figure 2 This is a schematic diagram of the structure of a control device for a permanent magnet synchronous motor provided in an embodiment of this application;

[0043] Figure 3 This is a schematic diagram of the structure of a control device provided in an embodiment of this application. Detailed Implementation

[0044] It should be noted that the terminology used in the embodiments of this application is only for explaining specific embodiments of this application and is not intended to limit this application. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, "at least one" or "one or more" means one, two or more. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0045] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0046] The control method for permanent magnet synchronous motors provided in this application embodiment can be applied to control equipment for permanent magnet synchronous motors.

[0047] The control method for permanent magnet synchronous motors provided in this application embodiment can be applied to various scenarios where permanent magnet synchronous motors need to be controlled. Specifically, when it is necessary to control a permanent magnet synchronous motor, the various steps of the control method for permanent magnet synchronous motors provided in this application embodiment 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 thus accurately perform vector control on the permanent magnet synchronous motor.

[0048] Please see Figure 1 , Figure 1 This application provides a flowchart of a control method for a permanent magnet synchronous motor. This control method can be applied to a control device for a permanent magnet synchronous motor. The control device can be connected to an extended state observer. The control method for the permanent magnet synchronous motor provided in this application can include steps S101 to S103, detailed below:

[0049] In S101, after the permanent magnet synchronous motor enters the constant speed operation state, the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor are input to the extended state observer, and the back electromotive force and rotor flux output by the extended state observer are obtained.

[0050] In this embodiment of the application, the control device can control the permanent magnet synchronous motor to rotate with a preset dq axis current by using 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.

[0051] Specifically, the control device can control the rotation of the permanent magnet synchronous motor with a preset dq-axis current through steps a to c, using a preset current-to-frequency ratio control strategy. Details are as follows:

[0052] In step a, the rotor of the permanent magnet synchronous motor is controlled to rotate to the target angle based on the dq axis current.

[0053] In this implementation, the control device can control the rotor of the permanent magnet synchronous motor to rotate to the target angle according to the preset dq axis current.

[0054] Step a is the rotor pre-positioning stage in the current-frequency ratio control strategy. In this stage, the initial position of the permanent magnet synchronous motor rotor is uncertain. However, since the d-axis direction of the dq-axis coordinate system on the rotor is always along the rotor flux direction, in practical applications, the d-axis current can be given to 0 in the virtual dq-axis coordinate system of the current-frequency ratio control strategy, and the q-axis current can be given to a preset constant in the virtual dq-axis coordinate system of the current-frequency ratio control strategy. The generated electromagnetic torque will rotate the rotor of the permanent magnet synchronous motor to a known target angle, thereby achieving the pre-positioning of the rotor. At this time, the angle difference between the virtual dq-axis coordinate system and the real dq-axis coordinate system is 90 degrees.

[0055] In step b, the rotor of the permanent magnet synchronous motor is controlled to rotate at a fixed acceleration.

[0056] In this implementation, after controlling the rotor of the permanent magnet synchronous motor to rotate to the target angle, the control device can control the rotor of the permanent magnet synchronous motor to accelerate its rotation at a fixed acceleration. This fixed acceleration can be set according to actual requirements.

[0057] Step b is the constant acceleration stage in the current-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 angle difference 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.

[0058] In practical applications, during the constant acceleration phase, the following speed calculation formula, electromagnetic torque formula, and torque balance equation can be used.

[0059] The formula for calculating speed can be:

[0060]

[0061] in, Angular velocity, These are the auto-increment angle and the FOC operation interruption time, respectively.

[0062] The formula for electromagnetic torque can be:

[0063] =1.5 cosθ ref

[0064] in, For the electromagnetic torque of the motor, This represents the number of pole pairs of the motor. For the rotor flux of the motor, Let q be the current given in the virtual dq-axis coordinate system. The angle difference between the virtual dq-axis coordinate system and the real dq-axis coordinate system.

[0065] The torque balance equation can be:

[0066]

[0067] in, For the electromagnetic torque of the motor, It is the load torque. This refers to the mechanical angular velocity of the motor.

[0068] In step c, after the rotor speed of the permanent magnet synchronous motor reaches the preset speed, the rotor of the permanent magnet synchronous motor is controlled to rotate at a constant speed of the preset speed.

[0069] Since the observation angle of the extended state observer continuously approaches the precise angle as the rotor speed of the permanent magnet synchronous motor (PMSM) increases, once the rotor speed reaches the preset speed, the observation angle of the extended state observer can be considered relatively accurate. At this point, the rotor of the PMSM can be controlled to rotate at the preset speed, thus enabling the PMSM to enter a constant-speed operation state. The preset speed can be set according to actual needs and is not limited here.

[0070] Once the permanent magnet synchronous motor has entered a constant speed operating state, the control equipment can control the permanent magnet synchronous motor by expanding the state observer.

[0071] Specifically, during the process of controlling the rotation of the permanent magnet synchronous motor, the control equipment can acquire 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 has entered the constant speed operation state, the control equipment can input the current two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor to the extended state observer, so as to obtain the back electromotive force and rotor flux from the extended state observer.

[0072] In one possible implementation, the control device can 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 detailed below:

[0073] In step d, the three-phase current values ​​of the permanent magnet synchronous motor are obtained and converted into two-phase static current values.

[0074] In this implementation, the control device can obtain the three-phase current values ​​of the permanent magnet synchronous motor through a current value acquisition device, and then convert the three-phase current values ​​into two-phase static current values ​​through a first preset transformation. Here, by way of example and not limitation, the first preset transformation can be the Clark transformation.

[0075] In step e, the two-phase quiescent current values ​​are used as the current input of the extended state observer, and the two voltage components of the dq coordinate system output by the current loop are obtained and converted into two-phase quiescent voltage values.

[0076] In this implementation, after obtaining the two-phase quiescent current values ​​of the permanent magnet synchronous motor, the control device can use these two-phase quiescent current values ​​as the current input to the extended state observer. After using these two-phase quiescent current values ​​as the current input to the extended state observer, the current loop connected to the control device will output two voltage components in the dq coordinate system. Based on this, the control device can obtain the two voltage components in the dq coordinate system output by the current loop, and convert these two voltage components into two-phase quiescent voltage values ​​through a second preset transformation. This allows the control device to obtain the two-phase quiescent current values ​​and two-phase quiescent voltage values ​​of the permanent magnet synchronous motor. Here, by way of example and not limitation, the second preset transformation can be the Park transformation.

[0077] After obtaining the two-phase static current and two-phase static voltage values ​​of the permanent magnet synchronous motor, the control device can input these values ​​into the extended state observer to obtain the back electromotive force and rotor flux output by the extended state observer.

[0078] In S102, the observed speed and rotor position of the permanent magnet synchronous motor are determined based on the back electromotive force and rotor flux linkage.

[0079] Because 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 large jitter, which leads to severe jitter in the observed rotational speed and 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 DC bias.

[0080] Based on this, in the embodiments of this application, after the control device obtains the back electromotive force and rotor flux output by the extended state observer, it can correct the back electromotive force through steps f to j, as detailed below:

[0081] In step f, the air gap flux in the αβ coordinate system is determined based on the rotor flux linkage.

[0082] In this implementation, the control device can determine the air gap flux in the αβ coordinate system based on 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.

[0083] In step g, the air gap flux in the αβ coordinate system is transformed into the air gap flux in the dq coordinate system based on the integrated rotor flux and the preset current model formula.

[0084] In this implementation, after determining the air gap flux linkage in the αβ coordinate system, the control device can transform the obtained air gap flux linkage in the αβ coordinate system into the air gap flux linkage in the dq coordinate system through a preset third transformation, based on the integrated rotor flux linkage and a preset current model formula. Here, as an example and not a limitation, the third preset transformation can be the Park transformation.

[0085] In step h, the air gap flux in the dq coordinate system is subtracted from the preset rotor flux constant, and then the first current component in the α coordinate system and the second current component in the β coordinate system are obtained by inverse transformation.

[0086] In this implementation, after the air gap flux in the dq coordinate system is obtained, the control device can subtract a preset rotor flux constant from the obtained air gap flux in the dq coordinate system. Then, the result of subtracting the preset rotor flux constant from the air gap flux in the dq coordinate system is transformed by 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.

[0087] In step i, the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system are determined based on the first current component and the second current component.

[0088] In this implementation, after obtaining the first current component and the second current component, the control device can determine the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system based on the first current component and the second current component.

[0089] Since the first and second current components obtained are the observed values ​​of the extended state observer, while the two current components included in the two-phase quiescent current values ​​previously input to the extended state observer are the actual values, the deviation value can be calculated based on the first and second current components obtained, as well as the two-phase quiescent current values. Then, the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system are obtained based on the deviation value.

[0090] For example, the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system can be determined based on the first current component and the second current component using the following formulas:

[0091]

[0092] in, Let be the air gap flux component in the α coordinate system. The air gap flux component in the β coordinate system. Inductance in the α coordinate system Inductance in the β coordinate system Let be the first current component in the α coordinate system. This represents the second current component in the β coordinate system. The rotor flux linkage component in the α coordinate system. Let be the rotor flux linkage component in the β coordinate system.

[0093] In the above formula, , The air gap flux linkage can be determined using the αβ coordinate system obtained from the control equipment. and It can be obtained through measurement; therefore, it can be obtained through the above formula. and Then based on the obtained and The first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system are determined.

[0094] In step j, the back electromotive force is corrected according to the first correction compensation term and the second correction compensation term.

[0095] In this implementation, after obtaining the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system, the control device can compensate for the parameter mismatch term and DC component in the back electromotive force according to the first and second correction compensation terms, thereby realizing the correction of the back electromotive force.

[0096] After correcting the back EMF, the control equipment can determine the rotor position of the permanent magnet synchronous motor based on the corrected back EMF and rotor flux linkage.

[0097] For example, the control device can construct an orthogonal phase-locked loop structure based on the corrected back electromotive force and rotor flux linkage using the following formula.

[0098] - =

[0099] in, This is the rotor flux difference. The rotor position estimated by the extended state observer.

[0100] After obtaining the orthogonal phase-locked loop structure, the control equipment can determine the observed speed and rotor position of the permanent magnet synchronous motor based on the orthogonal phase-locked loop structure.

[0101] In S103, the speed of the permanent magnet synchronous motor is determined to be stable based on the observed speed. After the speed of the permanent magnet synchronous motor is determined to be stable, vector control is performed on the permanent magnet synchronous motor based on the observed speed and rotor position.

[0102] After determining the observed speed, the control equipment can determine whether the speed of the permanent magnet synchronous motor is stable based on the observed speed. Specifically, the control equipment can determine whether the speed of the permanent magnet synchronous motor is stable in the following ways:

[0103] First, the control device can acquire a preset deviation coefficient and a preset duration threshold. Both the preset deviation coefficient and the preset duration threshold can be set according to actual needs. After acquiring the deviation coefficient and the duration threshold, the control device can determine the target speed range based on the preset speed of the permanent magnet synchronous motor and the deviation coefficient. Then, 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 for which the observed speed of the permanent magnet synchronous motor is within 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.

[0104] In practical applications, the specific values ​​of the preset deviation coefficient and the preset duration threshold can be adjusted to achieve a smooth switch from the current-frequency ratio control strategy to the extended state observer control strategy.

[0105] Once the speed of the permanent magnet synchronous motor is determined to be stable, the control equipment can perform vector control on the permanent magnet synchronous motor based on the observed speed and rotor position.

[0106] As can be seen from the above, in the control method for a permanent magnet synchronous motor provided in this application embodiment, after the permanent magnet synchronous motor enters the constant speed operation state, the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor are input to the extended state observer, and the back electromotive force and rotor flux linkage output by the extended state observer are obtained; based on the back electromotive force and rotor flux linkage, the observed speed and rotor position of the permanent magnet synchronous motor are determined; based on the observed speed, it is determined whether the speed of the permanent magnet synchronous motor is stable; after determining that the speed of the permanent magnet synchronous motor is stable, vector control is performed on the permanent magnet synchronous motor based on the observed speed and rotor position. Through the control method provided in this application embodiment, the rotor position of the permanent magnet synchronous motor can be accurately determined, thereby enabling accurate vector control of the permanent magnet synchronous motor and improving the control accuracy of the permanent magnet synchronous motor.

[0107] Based on the control method for permanent magnet synchronous motors provided in the above embodiments, this application further provides a control device for a permanent magnet synchronous motor that implements the above method embodiments. Please refer to [link to relevant documentation]. Figure 2 , Figure 2 This is a schematic diagram of the structure of a control device for a permanent magnet synchronous motor provided in an embodiment of this application. Figure 2 As shown, the control device 20 for the permanent magnet synchronous motor may include: a data acquisition unit 21, a data determination unit 22, and a control unit 23. Wherein:

[0108] 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 to the extended state observer after the permanent magnet synchronous motor enters the constant speed operation state, and to acquire the back electromotive force and rotor flux output by the extended state observer.

[0109] The data determination unit 22 is used to determine the observed speed and rotor position of the permanent magnet synchronous motor based on the back electromotive force and rotor flux linkage.

[0110] The control unit 23 is used to determine whether the speed of the permanent magnet synchronous motor is stable based on the observed speed. After determining that the speed of the permanent magnet synchronous motor is stable, the control unit performs vector control on the permanent magnet synchronous motor based on the observed speed and the rotor position.

[0111] Optionally, the control device 20 for the permanent magnet synchronous motor may further include a current-frequency ratio strategy control unit, wherein:

[0112] The frequency ratio strategy control unit is used for:

[0113] When the permanent magnet synchronous motor is stationary, the motor is rotated by a preset current-frequency ratio control strategy with a preset dq axis current until the motor enters the constant speed operation state.

[0114] Optionally, the frequency ratio strategy control unit is specifically used for:

[0115] The rotor of the permanent magnet synchronous motor is controlled to rotate to the target angle based on the dq axis current;

[0116] The rotor of the permanent magnet synchronous motor is controlled to rotate at a preset acceleration.

[0117] After the rotor speed of the permanent magnet synchronous motor reaches the preset speed, the rotor of the permanent magnet synchronous motor is controlled to rotate at the preset speed to allow the permanent magnet synchronous motor to enter the constant speed operation state.

[0118] Optionally, the control unit 23 is specifically used for:

[0119] Obtain the preset deviation coefficient and the preset duration threshold;

[0120] The target speed range is determined based on the preset speed and the deviation coefficient;

[0121] If the duration for which the observed rotational speed is within the target rotational speed range is greater than the duration threshold, then the rotational speed of the permanent magnet synchronous motor is determined to be stable.

[0122] Optionally, the data acquisition unit may also be used for:

[0123] Obtain the three-phase current values ​​of the permanent magnet synchronous motor and convert the three-phase current values ​​into the two-phase static current values;

[0124] The two-phase quiescent current values ​​are used as the current input of the extended state observer, and the two voltage components of the dq coordinate system output by the current loop are obtained and converted into the two-phase quiescent voltage values.

[0125] Optionally, the control device 20 for the permanent magnet synchronous motor may also include a correction unit, wherein:

[0126] The correction unit is specifically used for:

[0127] Determine the air gap flux linkage in the αβ coordinate system based on the rotor flux linkage;

[0128] Based on the integrated rotor flux linkage and the preset current model formula, the air gap flux linkage in the αβ coordinate system is transformed into the air gap flux linkage in the dq coordinate system.

[0129] 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.

[0130] Based on the first current component and the second current component, determine the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system;

[0131] The back electromotive force is corrected based on the first and second correction compensation terms.

[0132] Optionally, the control unit 23 is specifically used for:

[0133] An orthogonal phase-locked loop structure is constructed based on the back electromotive force and the rotor flux linkage, and the observed rotational speed and the rotor position are determined based on the orthogonal phase-locked loop structure.

[0134] It should be noted that the information interaction and execution process between the above-mentioned units are based on the same concept as the method embodiments of this application. Their specific functions and technical effects can be referred to the method embodiments section, and will not be repeated here.

[0135] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a control device provided in an embodiment of this application. Figure 3 As 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 a control method for a permanent magnet synchronous motor. When the processor 30 executes the computer program 32, it implements the steps described above in the embodiment of the control method for a permanent magnet synchronous motor, for example... Figure 1 S101~S103 are shown. Alternatively, when processor 30 executes computer program 32, it implements the functions of each module / unit in the above-described control device embodiment for the permanent magnet synchronous motor, for example... Figure 2 The functions of units 21-23 shown.

[0136] For example, computer program 32 can be divided into one or more modules / units, one or more of which are stored in memory 31 and executed by processor 30 to complete this application. One or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of computer program 32 in control device 3. For example, computer program 32 can be divided into a data determination unit and a control unit; the specific functions of each unit are described in [reference needed]. Figure 2 The relevant descriptions in the corresponding embodiments are not repeated here.

[0137] Those skilled in the art will understand that Figure 3 This is merely an example of control device 3 and does not constitute a limitation on control device 3. It may include more or fewer components than shown, or combine certain components, or use different components.

[0138] The processor 30 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0139] The memory 31 can be an internal storage unit of the control device 3, such as a hard disk or RAM of the control device 3. The memory 31 can also be an external storage device of the control device 3, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, or flash card equipped on the control device 3. Furthermore, the memory 31 can include both internal storage units and external storage devices 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 can also be used to temporarily store data that has been output or will be output.

[0140] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units is merely an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the control device for the permanent magnet synchronous motor can be divided into different functional units to complete all or part of the functions described above. The functional units in the embodiments 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. Furthermore, the specific names of the functional units are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0141] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, can implement the steps in the various method embodiments described above.

[0142] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the steps described in the various method embodiments above.

[0143] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, refer to the relevant descriptions of other embodiments.

[0144] Those skilled in the art will recognize that the units and algorithm steps of the various examples 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 implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0145] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A control method for a permanent magnet synchronous motor, characterized in that, A control device for a permanent magnet synchronous motor, the control device being connected to an extended state observer; the control method for the permanent magnet synchronous motor includes: After the permanent magnet synchronous motor enters the constant speed operation state, the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor are input to the extended state observer, and the back electromotive force and rotor flux output by the extended state observer are obtained. Based on the back electromotive force and rotor flux linkage, the observed speed and rotor position of the permanent magnet synchronous motor are determined. Based on 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 based on the observed rotational speed and the rotor position. After obtaining the back electromotive force and rotor flux output by the extended state observer, the method further includes: Based on the rotor flux linkage, determine the air gap flux linkage in the αβ coordinate system; Based on the integrated rotor flux linkage and the preset current model formula, the air gap flux linkage in the αβ coordinate system is transformed into the air gap flux linkage 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. Based on the first current component and the second current component, determine the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system; The back electromotive force is corrected according to the first correction compensation term and the second correction compensation term.

2. The method according to claim 1, characterized in that, Before the permanent magnet synchronous motor enters the constant speed operation state, it also includes: When the permanent magnet synchronous motor is stationary, the motor is rotated by a preset current-frequency ratio control strategy with a preset dq axis current until the 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 using a preset current-to-frequency ratio control strategy includes: The rotor of the permanent magnet synchronous motor is controlled to rotate to the target angle based on the dq axis current; The rotor of the permanent magnet synchronous motor is controlled to rotate at a preset acceleration. After the rotor speed of the permanent magnet synchronous motor reaches the preset speed, the rotor of the permanent magnet synchronous motor is controlled to rotate at the preset speed to allow the permanent magnet synchronous motor to enter the constant speed operation state.

4. The method according to claim 3, characterized in that, The step of determining whether the speed of the permanent magnet synchronous motor is stable based on the observed speed includes: Obtain the preset deviation coefficient and the preset duration threshold; The target speed range is determined based on the preset speed and the deviation coefficient; If the duration for which the observed rotational speed is within the target rotational speed range is greater than the duration threshold, then the rotational speed of the permanent magnet synchronous motor is determined to be stable.

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

6. The method according to any one of claims 1 to 5, characterized in that, The step of determining the observed speed and rotor position of the permanent magnet synchronous motor based on the back electromotive force and rotor flux linkage includes: An orthogonal phase-locked loop structure is constructed based on the back electromotive force and the rotor flux linkage, and the observed rotational speed and the rotor position are determined based on the orthogonal phase-locked loop structure.

7. A control device for a permanent magnet synchronous motor, characterized in that, A control device for a permanent magnet synchronous motor, the control device being connected to an extended state observer; the control device for the permanent magnet synchronous motor includes: The data acquisition unit is used to input the two-phase static current value and the two-phase static voltage value of the permanent magnet synchronous motor to the extended state observer after the permanent magnet synchronous motor enters the constant speed operation state, and to acquire the back electromotive force and rotor flux output by the extended state observer. The data determination unit is used to determine the observed speed and rotor position of the permanent magnet synchronous motor based on the back electromotive force and rotor flux linkage. The control unit is used to determine whether the speed of the permanent magnet synchronous motor is stable based on the observed speed, and after determining that the speed of the permanent magnet synchronous motor is stable, to perform vector control on the permanent magnet synchronous motor based on the observed speed and the rotor position; Calibration unit, used for: Based on the rotor flux linkage, determine the air gap flux linkage in the αβ coordinate system; Based on the integrated rotor flux linkage and the preset current model formula, the air gap flux linkage in the αβ coordinate system is transformed into the air gap flux linkage 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. Based on the first current component and the second current component, determine the first correction compensation term in the α coordinate system and the second correction compensation term in the β coordinate system; The back electromotive force is corrected according to the first correction compensation term and the second correction compensation term.

8. 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, it implements each step of the control method for a permanent magnet synchronous motor as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the control method for the permanent magnet synchronous motor as described in any one of claims 1 to 6.

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