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

Abstract

The invention discloses a control method and device of a permanent magnet synchronous motor and a storage medium. The method comprises the steps of obtaining an equivalent back electromotive force of the permanent magnet synchronous motor in an operation state based on a preset sliding mode observer; wherein the sliding-mode observer is obtained according to a current state equation of the permanent magnet synchronous motor under the two-phase static coordinate system and a preset sliding-mode observer control function, and the sliding-mode observer control function is obtained according to a preset continuous derivable novel function; extracting a rotor position and a rotor rotating speed in the equivalent back electromotive force according to a phase-locked loop; according to the rotor position and the rotor rotating speed, an inverter is controlled in a closed-loop mode to drive the permanent magnet synchronous motor to operate. When the permanent magnet synchronous motor is controlled, the nonlinear characteristic of a motor control system can be better matched, the stability precision and the tracking precision of the line counter electromotive force can be greatly improved, and therefore the observation precision of the rotor position and the rotating speed is improved.

Description

Technical Field

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

[0002] In the sensorless PMSM control system, accurate angle observation is the basis for achieving high-performance control. Lack of accurate angle information will lead to unstable control and may even cause oscillation and reversal. Only when the angle observation has good accuracy and response can the current vector be correctly aligned with the rotor magnetic field, thereby efficiently generating the required torque while reducing unnecessary hysteresis and eddy current losses.

[0003] The traditional sliding mode sensorless control strategy uses the sign function sign(x) to design a constant velocity convergence law, because it has discontinuous jumps near the sliding surface, which can prompt the system state to quickly cross the sliding surface. However, the abrupt change and discontinuity of the sign function will also introduce the problem of jitter. There are many existing technologies for optimizing the traditional sliding mode jitter problem, such as using a continuous function to replace the sign function sign(x) in the traditional sliding mode convergence law, such as: hyperbolic tangent function tanh(x), Gaussian error function erf(x), etc.; there are also methods such as using adaptive or fuzzy control to adjust the sliding mode gain; there are also high-order convergence laws that add nonlinear terms to the sliding mode control law; or a combination of the above methods.

[0004] However, if the design of the reaching law includes too complex functions, it will increase the requirements for the performance of the microcontroller; otherwise, the carrier ratio must be sacrificed in exchange for a longer time for the microcontroller to perform relevant calculations, or the accuracy and space must be sacrificed to calculate the function value through table lookup and interpolation methods. Therefore, it is particularly important to develop a reaching law that can optimize the accuracy of sliding mode observation while not being too dependent on the performance of the microcontroller. Summary of the invention

[0005] The present application provides a control method, device, equipment and storage medium for a permanent magnet synchronous motor, which can solve the technical problems existing in the above-mentioned related technologies.

[0006] In a first aspect, an embodiment of the present application provides a control method for a permanent magnet synchronous motor, which adopts the following technical solution:

[0007] A control method for a permanent magnet synchronous motor, the method comprising:

[0008] The equivalent back electromotive force of the permanent magnet synchronous motor in the running state is obtained based on a preset sliding mode observer; wherein the sliding mode observer is obtained according to the current state equation of the permanent magnet synchronous motor in a two-phase stationary coordinate system and a preset sliding mode observer control function, and the sliding mode observer control function is obtained according to a preset continuously differentiable new function;

[0009] Extracting the rotor position and rotor speed from the equivalent back electromotive force according to a phase-locked loop;

[0010] According to the rotor position and the rotor speed, a closed-loop control inverter drives the permanent magnet synchronous motor to operate.

[0011] In combination with the first aspect, in one implementation, the method for constructing the sliding mode observer includes the following steps:

[0012] Establish the voltage equation of the surface mounted permanent magnet synchronous motor in a two-phase stationary coordinate system;

[0013] Derivation of a current state equation in a two-phase stationary coordinate system by using the voltage equation in the two-phase stationary coordinate system;

[0014] According to the preset new continuously differentiable function, the control function corresponding to the sliding mode observer is obtained;

[0015] Constructing a sliding mode stator current observer according to a control function corresponding to the sliding mode observer and a current state equation in the two-phase stationary coordinate system;

[0016] Define the calculation equations for the current observation errors of the α-axis and β-axis of the permanent magnet synchronous motor;

[0017] According to the calculation equation of the current observation error of the α-axis and the β-axis, the sliding mode stator current observer and the current state equation in the two-phase stationary coordinate system, a current error dynamic equation is obtained;

[0018] According to the current error dynamic equation, the calculation equation of the equivalent back electromotive force after the system enters the sliding surface is obtained.

[0019] In combination with the first aspect, in one implementation, the preset continuously differentiable new function obtains the control function corresponding to the sliding mode observer, and adopts the following formula:

[0020]

[0021] u(x)=k gain h(x) (4)

[0022] Wherein, formula (3) is the preset continuously differentiable new function, formula (4) is the sliding mode observer control function, k and a are the scaling coefficient of the new function and the index for controlling the steepness of the new function, respectively, k>0 and a>0; kgain is the sliding mode gain coefficient obtained according to the sliding surface analysis of the system.

[0023] In combination with the first aspect, in one implementation, the sliding mode gain coefficient is analyzed by taking the following steps:

[0024] Select the current error as the sliding surface;

[0025] constructing a Lyapunov function on the sliding surface;

[0026] According to the Lyapunov stability requirement, a value range of the sliding mode gain coefficient is determined, and the sliding mode gain coefficient is determined from the value range of the sliding mode gain coefficient.

[0027] In combination with the first aspect, in one implementation, it is characterized in that, in constructing the sliding mode stator current observer according to the control function corresponding to the sliding mode observer and the current state equation in the two-phase stationary coordinate system, the sliding mode stator current observer adopts the following formula:

[0028]

[0029] In the formula They are the α-axis current observation value, the β-axis current observation value, the control input of the α-axis observer, and the control input of the β-axis observer.

[0030] In combination with the first aspect, in one implementation, the voltage equation of the surface-mounted permanent magnet synchronous motor in a two-phase stationary coordinate system adopts the following formula:

[0031]

[0032] Where uα and uβ are the voltages of the stator on the α and β axes, Rs is the stator resistance, and Ls is the stator inductance; iα and iβ are the currents flowing through the α and β axes respectively, eα and eβ are the back electromotive forces of the α and β axes, ωe is the rotor electrical angular velocity, Ψf is the permanent magnet flux, and θr is the rotor angle.

[0033] In combination with the first aspect, in one implementation, the current state equation in the two-phase stationary coordinate system adopts the following formula:

[0034]

[0035] In a second aspect, an embodiment of the present application provides a control device for a permanent magnet synchronous motor, which adopts the following technical solution:

[0036] A control device for a permanent magnet synchronous motor, the control device for the permanent magnet synchronous motor comprising:

[0037] An observation module, which is configured to obtain an equivalent back electromotive force of the permanent magnet synchronous motor in a running state based on a preset sliding mode observer; wherein the sliding mode observer is obtained according to a current state equation of the permanent magnet synchronous motor in a two-phase stationary coordinate system and a preset sliding mode observer control function, and the sliding mode observer control function is obtained according to a preset continuously differentiable new function;

[0038] The control module is configured to extract the rotor position and the rotor speed from the equivalent back electromotive force according to a phase-locked loop; and, according to the rotor position and the rotor speed, perform closed-loop control on the inverter to drive the motor to operate.

[0039] In a third aspect, the embodiment of the present application provides a control device for a permanent magnet synchronous motor, which adopts the following technical solution:

[0040] A control device for a permanent magnet synchronous motor, the control device for the permanent magnet synchronous motor comprising a processor, a memory, a driver, and a control program for the permanent magnet synchronous motor stored in the memory and executable by the processor, wherein when the control program for the permanent magnet synchronous motor is executed by the processor, the steps of the control method for the permanent magnet synchronous motor as described above are implemented.

[0041] In a fourth aspect, an embodiment of the present application provides a storage medium, which adopts the following technical solution:

[0042] A storage medium stores a control program of a permanent magnet synchronous motor, wherein when the control program of the permanent magnet synchronous motor is executed by a processor, the steps of the control method of the permanent magnet synchronous motor as described above are implemented.

[0043] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0044] When using a sliding mode observer to obtain the equivalent back electromotive force of a permanent magnet synchronous motor, since the control function of the sliding mode observer is designed based on a preset continuously differentiable new function, this method can effectively reduce jitter compared to the traditional constant velocity reaching law. Compared with using tanh(x) and sat(x) to replace sign(x) in the constant velocity reaching law, the new function has the advantages of continuous differentiability, sensitivity to near zero, and simple calculation process. It can better match the nonlinear characteristics of the motor control system, and can greatly improve the stability accuracy and tracking accuracy of the line back electromotive force, thereby improving the observation accuracy of the rotor position and speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1This is a flow chart of an embodiment of a control method for a permanent magnet synchronous motor of the present application;

[0046] Figure 2 The waveform of the control function u(x) proposed in the control method of the permanent magnet synchronous motor of the present application when the sliding mode gain k1 is 1, the scaling factor k is 10, and the exponent a is 1 / 2, 1, and 2 respectively;

[0047] Figure 3(a) shows the k gain Comparison diagram of the α-axis current curve observed by the observer with sign(x) as the control function and the actual α-axis current curve;

[0048] FIG3( b ) is a partial enlarged view of FIG4( a );

[0049] Figure 4(a) shows the k gain Comparison diagram of the α-axis current curve observed by the observer with tanh(x) as the control function and the actual α-axis current curve;

[0050] FIG4( b ) is a partial enlarged view of FIG4( a );

[0051] FIG5(a) is a comparison diagram of the α-axis current curve observed by the observer using u(x) as the control function based on the new function and the actual α-axis current curve;

[0052] FIG5( b ) is a partial enlarged view of FIG5( a );

[0053] Figure 6(a) shows the simulation of the system at 800 rpm, using k gain sign(x) is a comparison chart of the speed observed by the observer of the control function and the actual speed;

[0054] FIG6( b ) is a partial enlarged view of FIG6( a );

[0055] Figure 7(a) shows the simulation of the system at 800 rpm, using k gain Comparison diagram of the speed observed by the observer with tanh(x) as the control function and the actual speed;

[0056] FIG7( b ) is a partial enlarged view of FIG8( a );

[0057] Figure 8(a) shows the simulation of the system at 800 rpm, using k gain h(x) is a comparison chart of the speed observed by the observer of the control function and the actual speed;

[0058] FIG8( b ) is a partial enlarged view of FIG8( a );

[0059] Fig. 9 This is the simulation of the system at 800rpm; kgain h(x) is a comparison diagram of the rotor observed position and actual position observed by the observer of the control function;

[0060] Fig.10 This is a functional module diagram of an embodiment of a control device for a permanent magnet synchronous motor of the present application;

[0061] Fig.11 This is a schematic diagram of the hardware structure of the control device of the permanent magnet synchronous motor involved in the embodiment of the present application. DETAILED DESCRIPTION

[0062] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0063] In the sensorless PMSM control system, accurate angle observation is the basis for achieving high-performance control. Lack of accurate angle information will lead to unstable control and may even cause oscillation and reversal. Only when the angle observation has good accuracy and response can the current vector be correctly aligned with the rotor magnetic field, thereby efficiently generating the required torque while reducing unnecessary hysteresis and eddy current losses.

[0064] The traditional sliding mode sensorless control strategy uses the sign function sign(x) to design a constant velocity convergence law, because it has discontinuous jumps near the sliding surface, which can prompt the system state to quickly cross the sliding surface. However, the abrupt change and discontinuity of the sign function will also introduce the problem of jitter. There are many existing technologies for optimizing the traditional sliding mode jitter problem, such as using a continuous function to replace the sign function sign(x) in the traditional sliding mode convergence law, such as: hyperbolic tangent function tanh(x), Gaussian error function erf(x), etc.; there are also methods such as using adaptive or fuzzy control to adjust the sliding mode gain; there are also high-order convergence laws that add nonlinear terms to the sliding mode control law; or a combination of the above methods.

[0065] However, if the design of the reaching law includes too complex functions, it will increase the requirements for the performance of the microcontroller; otherwise, the carrier ratio must be sacrificed in exchange for a longer time for the microcontroller to perform relevant calculations, or the accuracy and space must be sacrificed to calculate the function value through table lookup and interpolation methods. Therefore, it is particularly important to develop a reaching law that can optimize the accuracy of sliding mode observation while not being too dependent on the performance of the microcontroller.

[0066] Based on the above problems, the present application provides a control method, device, equipment and storage medium for a permanent magnet synchronous motor. The key point of the invention is that when using a sliding mode observer to obtain the equivalent back electromotive force of the permanent magnet synchronous motor, since the control function of the sliding mode observer is designed based on a preset continuously differentiable new function, compared with the traditional constant velocity approaching law, this method can effectively reduce jitter. Compared with using tanh(x) and sat(x) instead of sign(x) in the constant velocity approaching law, the new function has the advantages of continuous differentiability, sensitivity to near zero, and simple calculation process. It can better match the nonlinear characteristics of the motor control system, and can greatly improve the stability accuracy and tracking accuracy of the line back electromotive force, thereby improving the observation accuracy of the rotor position and speed.

[0067] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0068] In a first aspect, an embodiment of the present application provides a control method for a permanent magnet synchronous motor.

[0069] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the control method of the permanent magnet synchronous motor of the present application. Figure 1 As shown, the control method of the permanent magnet synchronous motor includes:

[0070] S100, obtaining the equivalent back electromotive force of the permanent magnet synchronous motor in the running state based on a preset sliding mode observer; wherein the sliding mode observer is obtained according to the current state equation of the permanent magnet synchronous motor in a two-phase stationary coordinate system and a preset sliding mode observer control function, and the sliding mode observer control function is obtained according to a preset continuously differentiable new function;

[0071] S200, extracting the rotor position and rotor speed from the equivalent back electromotive force according to a phase-locked loop;

[0072] S300: According to the rotor position and the rotor speed, a closed-loop control inverter drives the permanent magnet synchronous motor to operate.

[0073] Specifically, before obtaining the equivalent back electromotive force of the permanent magnet synchronous motor in the running state based on the preset sliding mode observer, the permanent magnet synchronous motor is started by the three-stage starting technology, and the permanent magnet synchronous motor speed closed-loop control based on the sliding mode observer is switched on after the system is stable. Subsequently, the equivalent back electromotive force is obtained by using the preset sliding mode observer, and the rotor position and speed in the equivalent back electromotive force are extracted by using the phase-locked loop. According to the obtained speed information, the voltage Ud and Uq in the rotating coordinate system are controlled by the speed PI controller of the outer loop, and then the voltage Uα and Uβ in the stationary coordinate system are calculated according to the obtained rotor position information and the voltage Ud and Uq in the two-phase rotating coordinate system, so as to further calculate the action time of the two non-zero vectors of the seven-segment SVPWM, control the inverter to drive the motor operation, and realize closed-loop control.

[0074] Furthermore, in one embodiment, the method for constructing the sliding mode observer comprises the following steps:

[0075] F100. Establish the voltage equation of the surface-mounted permanent magnet synchronous motor in a two-phase stationary coordinate system;

[0076] F200, deriving a current state equation in a two-phase stationary coordinate system through the voltage equation in the two-phase stationary coordinate system;

[0077] F300, according to the preset continuously differentiable new function, obtain the control function corresponding to the sliding mode observer;

[0078] F400, constructing a sliding mode stator current observer according to the control function corresponding to the sliding mode observer and the current state equation in the two-phase stationary coordinate system;

[0079] F500, define the calculation equation of the current observation error of the α-axis and β-axis of the permanent magnet synchronous motor;

[0080] F600, obtaining a current error dynamic equation according to the calculation equation of the current observation error of the α-axis and the β-axis, the sliding mode stator current observer and the current state equation in the two-phase stationary coordinate system;

[0081] F700. According to the current error dynamic equation, the equivalent back electromotive force after the system enters the sliding surface is obtained.

[0082] Specifically, in step F100, a voltage equation of the surface-mounted permanent magnet synchronous motor in a two-phase stationary coordinate system is established. The voltage equation of the surface-mounted permanent magnet synchronous motor in a two-phase stationary coordinate system is:

[0083]

[0084] Where u α 、u βis the voltage of the stator on the α and β axes, R s is the stator resistance, L s is the stator inductance; i α 、i β are the currents flowing through the α-axis and β-axis respectively, e α 、e β is the back electromotive force of the α-axis and the β-axis, ω e is the rotor electrical angular velocity, Ψ f is the permanent magnet flux, θ r is the rotor angle.

[0085] F200, deriving the current state equation in the two-phase stationary coordinate system through the voltage equation in the two-phase stationary coordinate system, the current state equation in the two-phase stationary coordinate system is specifically:

[0086]

[0087] F300. According to the preset continuous differentiable new function, the control function corresponding to the sliding mode observer is obtained. The control function corresponding to the sliding mode observer adopts the following formula:

[0088]

[0089] u(x)=k gain h(x) (4)

[0090] Wherein, formula (3) is the constructed new continuous differentiable function, formula (4) is the sliding mode observer control function, k and a are the scaling coefficient of the new function and the index for controlling the steepness of the new function, respectively, k>0 and a>0; k gain is the sliding mode gain coefficient obtained based on the sliding surface analysis of the system.

[0091] For example, in some embodiments, the control function u(x) waveform when the sliding mode gain k1 is 1, the scaling factor k is 10, and the exponent a is 1 / 2, 1, and 2 respectively can be referred to Figure 2 ;

[0092] F400, constructing a sliding mode stator current observer according to the control function corresponding to the sliding mode observer and the current state equation in the two-phase stationary coordinate system, wherein the sliding mode stator current observer adopts the following formula:

[0093]

[0094] In the formula are the α-axis current observation value, the β-axis current observation value, the control input of the α-axis observer, and the control input of the β-axis observer respectively;

[0095] F500, define the calculation equation of the current observation error of the permanent magnet synchronous motor α axis and β axis. Specifically, define the current observation error of the α and β axes as

[0096]

[0097] F600, according to the calculation equation of the current observation error of the α-axis and the β-axis, the sliding mode stator current observer and the current state equation in the two-phase stationary coordinate system, the current error dynamic equation is obtained. Specifically, the current error dynamic equation is obtained by subtracting the equation group (2) from the equation group (5):

[0098]

[0099] F700, according to the current error dynamic equation, obtaining the calculation equation of the equivalent back electromotive force after the system enters the sliding surface, including the following steps:

[0100] F710, select current error as sliding surface

[0101] F720, construct Lyapunov function To satisfy Lyapunov stability, the sliding mode gain k gain The value of must satisfy:

[0102] k gain >=max{|e α |,|e β |} (8)

[0103] F730, when the system enters the sliding surface, there is At this time, the control quantity can be regarded as the equivalent back electromotive force, that is, the back electromotive force observation value:

[0104]

[0105] Finally, the sliding mode observer based on the novel function control function proposed in the present invention, when using the sliding mode observer to control the permanent magnet synchronous motor, compared with the prior art, has the following technical effects:

[0106] 1. Enhanced observation accuracy: Observation errors are significantly reduced, improving the accuracy of motor control.

[0107] 2. Fast convergence characteristics: By adjusting the parameters in the reaching law, the convergence speed of the observer can be adjusted to improve the dynamic performance.

[0108] 3. Reduce system jitter: The optimized reaching law design effectively reduces the jitter phenomenon during the observation process, which is beneficial to the smooth and efficient operation of the motor.

[0109] 4. Improve economic benefits: By improving the observation accuracy and reducing the system jitter, unnecessary hysteresis and eddy current losses are reduced, and the energy utilization rate is improved;

[0110] 5. Reduced hardware cost: The present invention improves the observation accuracy without increasing the requirements for the single-chip microcomputer, thus reducing the cost of practical application.

[0111] The present invention aims to use the power function x a A new function similar to tanh(x) and erf(x) is constructed to replace the sign function sign(x) in the uniform velocity reaching law of the traditional sliding mode. However, the implementation of tanh(x) and erf(x) both involve the natural exponential function e x , compared to the natural exponential function e x Power function x a It is easier for the microcontroller to perform calculations under certain special values ​​of the exponent a.

[0112] Because the natural exponential function e x The calculation of tanh(x) and erf(x) usually involves complex algorithms, such as Taylor series expansion, Cordic algorithm, or lookup table and interpolation methods. These methods may require more calculation steps and / or memory access, especially when a certain accuracy is guaranteed. Therefore, functions such as tanh(x) and erf(x) are more difficult for microcontrollers to calculate.

[0113] But the power function x a When a takes 1, the function value does not need any extra calculation; when a takes 1 / 2, the square root calculation can also be efficiently realized by algorithms such as Newton's iteration method, and many modern single-chip microcomputers have hardware instructions to support fast calculation of square roots, which makes the calculation of square roots relatively efficient, especially when dealing with floating-point numbers, many single-chip microcomputers have special instruction sets to accelerate such operations, and the most suitable a value can be selected according to the performance of the single-chip microcomputer during application. And the new function designed by the present invention has similar properties to tanh (x) and erf (x), has the advantages of continuous differentiability, sensitivity to near 0, simpler calculation process, etc., can better match the nonlinear characteristics of the motor control system, can greatly improve the stability accuracy and tracking accuracy of the line back electromotive force, thereby improving the observation accuracy of the rotor position and speed.

[0114] In summary, the synovial observer optimization method provided by the present invention solves the contradiction between observation accuracy, dynamic performance and hardware performance in the prior art, enhances the overall performance of the PMSM sensorless control system without over-reliance on hardware performance, and is generally suitable for most single-chip microcomputers to perform sensorless FOC control of permanent magnet synchronous motors.

[0115] In order to further effectively reflect the control effect of the sliding mode observer provided by this application, this application provides the attached Figure 3(a)-10 For reference and proof of effect:

[0116] Figure 3(a) shows the k gain Comparison between the α-axis current curve observed by the observer using sign(x) as the control function and the actual α-axis current curve;

[0117] FIG3( b ) is a partial enlargement of FIG3( a ), where the current jitter can be clearly seen.

[0118] Figure 4(a) shows the k gain The comparison between the α-axis current curve observed by the observer with tanh(x) as the control function and the actual α-axis current curve. FIG4(b) is a partial enlargement of FIG4(a). It can be clearly seen that the current jitter is significantly weakened.

[0119] FIG5(a) is a comparison between the α-axis current curve observed by the observer using u(x) as the control function based on the new function and the actual α-axis current curve. FIG5(b) is a partial enlargement of FIG5(a). It can be clearly seen that the current jitter is significantly weakened, and the new function can achieve a control effect similar to tanh(x).

[0120] Figure 6(a) shows the simulation of the system at 800 rpm, using k gain The comparison between the speed observed by the observer with sign(x) as the control function and the actual speed. Figure 6(b) is a partial enlargement of Figure 6(a).

[0121] Figure 7(a) shows the simulation of the system at 800 rpm, using k gain Figure 7(b) shows a comparison between the speed observed by the observer with tanh(x) as the control function and the actual speed. Figure 7(a) is a partial enlargement of Figure 7(a). The speed is obviously more stable than when sign(x) is used as the control function.

[0122] Figure 8(a) shows the simulation of the system at 800 rpm, using k gain h(x) is used as the comparison between the speed observed by the observer and the actual speed. Figure 8(b) is a partial enlargement of Figure 8(a). gain h(x) is the control function that can achieve k gain tanh(x) has a similar effect to the control function.

[0123] Fig. 9This is a simulation of the system at 800rpm; the new function u(x) is used to design the control input observer to observe the observed rotor position and the actual position. The lag between the observed position and the actual position is due to the presence of a low-pass filter LPF in the system, which causes a phase delay in the rotor position information. In the application, corresponding compensation can be made based on the cutoff frequency of the LPF and the rotor frequency.

[0124] In a second aspect, an embodiment of the present application also provides a control device for a permanent magnet synchronous motor.

[0125] In one embodiment, referring to Fig.10 , Fig.10 This is a functional module diagram of an embodiment of a control device for a permanent magnet synchronous motor of the present application. Fig.10 As shown, the control device of the permanent magnet synchronous motor includes:

[0126] Among them, the functional implementation of each module in the above-mentioned permanent magnet synchronous motor control device corresponds to the various steps in the above-mentioned permanent magnet synchronous motor control method embodiment, and its functions and implementation processes are no longer repeated here one by one.

[0127] In a third aspect, an embodiment of the present application provides a control device for a permanent magnet synchronous motor. The control device for the permanent magnet synchronous motor may be a personal computer (PC), a laptop computer, a server, or other device with a data processing function.

[0128] Reference Fig.11 , Fig.11 Schematic diagram of the hardware structure of the control device of the permanent magnet synchronous motor involved in the embodiment of the present application. In the embodiment of the present application, the control device of the permanent magnet synchronous motor may include a processor, a memory, a communication interface and a communication bus.

[0129] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0130] The communication interface includes input / output (I / O) interface, physical interface and logical interface, etc., which are used to realize the interconnection of devices inside the control device of the permanent magnet synchronous motor, and the interface used to realize the interconnection between the control device of the permanent magnet synchronous motor and other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, a fiber optic interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0131] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0132] The processor may be a general-purpose processor, and the general-purpose processor may call the control program of the permanent magnet synchronous motor stored in the memory, and execute the control method of the permanent magnet synchronous motor provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the control program of the permanent magnet synchronous motor is called may refer to the various embodiments of the control method of the permanent magnet synchronous motor of the present application, and will not be repeated here.

[0133] Those skilled in the art will understand that Fig.11 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0134] In a fourth aspect, an embodiment of the present application also provides a storage medium.

[0135] The storage medium of the present application stores a control program of a permanent magnet synchronous motor, wherein when the control program of the permanent magnet synchronous motor is executed by a processor, the steps of the control method of the permanent magnet synchronous motor as described above are implemented.

[0136] Among them, the method implemented when the control program of the permanent magnet synchronous motor is executed can refer to the various embodiments of the control method of the permanent magnet synchronous motor of the present application, and will not be repeated here.

[0137] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0138] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0139] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0140] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0141] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0142] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0143] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A control method for a permanent magnet synchronous motor, characterized in that: The method comprises: The equivalent back electromotive force of the permanent magnet synchronous motor in the running state is obtained based on a preset sliding mode observer; wherein the sliding mode observer is obtained according to the current state equation of the permanent magnet synchronous motor in a two-phase stationary coordinate system and a preset sliding mode observer control function, and the sliding mode observer control function is obtained according to a preset continuously differentiable new function; Extracting the rotor position and rotor speed from the equivalent back electromotive force according to a phase-locked loop; According to the rotor position and the rotor speed, a closed-loop control inverter drives the permanent magnet synchronous motor to operate.

2. The control method of the permanent magnet synchronous motor according to claim 1, characterized in that: The method for constructing the sliding mode observer comprises the following steps: Establish the voltage equation of the surface mounted permanent magnet synchronous motor in a two-phase stationary coordinate system; Derivation of a current state equation in a two-phase stationary coordinate system by using the voltage equation in the two-phase stationary coordinate system; According to the preset new continuously differentiable function, the control function corresponding to the sliding mode observer is obtained; Constructing a sliding mode stator current observer according to a control function corresponding to the sliding mode observer and a current state equation in the two-phase stationary coordinate system; Define the calculation equations for the current observation errors of the α-axis and β-axis of the permanent magnet synchronous motor; According to the calculation equation of the current observation error of the α-axis and the β-axis, the sliding mode stator current observer and the current state equation in the two-phase stationary coordinate system, a current error dynamic equation is obtained; According to the current error dynamic equation, the equivalent back electromotive force after the system enters the sliding surface is obtained.

3. The control method of the permanent magnet synchronous motor according to claim 2, characterized in that: According to the preset continuously differentiable new function, the control function corresponding to the sliding mode observer is obtained, and the following formula is adopted: u(x)=k gain h(x) (4) Wherein, formula (3) is the preset continuously differentiable new function, formula (4) is the sliding mode observer control function, k and a are the scaling coefficient of the new function and the index for controlling the steepness of the new function, respectively, k>0 and a>0; k gain is the sliding mode gain coefficient obtained based on the sliding surface analysis of the system.

4. The control method of the permanent magnet synchronous motor according to claim 3, characterized in that: The sliding mode gain coefficient is analyzed by taking the following steps: Select the current error as the sliding surface; constructing a Lyapunov function on the sliding surface; According to the Lyapunov stability requirement, a value range of the sliding mode gain coefficient is determined, and the sliding mode gain coefficient is determined from the value range of the sliding mode gain coefficient.

5. The control method of the permanent magnet synchronous motor according to claim 3, characterized in that: In the construction of the sliding mode stator current observer according to the control function corresponding to the sliding mode observer and the current state equation in the two-phase stationary coordinate system, the sliding mode stator current observer adopts the following formula: In the formula They are the α-axis current observation value, the β-axis current observation value, the control input of the α-axis observer, and the control input of the β-axis observer.

6. The control method of the permanent magnet synchronous motor according to claim 2, characterized in that: The voltage equation of the surface-mounted permanent magnet synchronous motor in a two-phase stationary coordinate system adopts the following formula: Where u α 、u β is the voltage of the stator on the α and β axes, R s is the stator resistance, L s is the stator inductance; i α 、i β are the currents flowing through the α-axis and β-axis respectively, e α 、e β is the back electromotive force of the α-axis and the β-axis, ω e is the rotor electrical angular velocity, Ψ f is the permanent magnet flux, θ r is the rotor angle.

7. The control method of the permanent magnet synchronous motor according to claim 6, characterized in that: The current state equation in the two-phase stationary coordinate system adopts the following formula:

8. A control device for a permanent magnet synchronous motor, characterized in that: The control device of the permanent magnet synchronous motor comprises: An observation module, which is configured to obtain an equivalent back electromotive force of the permanent magnet synchronous motor in a running state based on a preset sliding mode observer; wherein the sliding mode observer is obtained according to a current state equation of the permanent magnet synchronous motor in a two-phase stationary coordinate system and a preset sliding mode observer control function, and the sliding mode observer control function is obtained according to a preset continuously differentiable new function; The control module is configured to extract the rotor position and the rotor speed from the equivalent back electromotive force according to a phase-locked loop; and, according to the rotor position and the rotor speed, perform closed-loop control on the inverter to drive the motor to operate.

9. A control device for a permanent magnet synchronous motor, characterized in that: The control device of the permanent magnet synchronous motor includes a processor, a memory, and a control program of the permanent magnet synchronous motor stored in the memory and executable by the processor, wherein when the control program of the permanent magnet synchronous motor is executed by the processor, the steps of the control method of the permanent magnet synchronous motor as described in any one of claims 1 to 7 are implemented.

10. A storage medium, characterized in that: The storage medium stores a control program of the permanent magnet synchronous motor, wherein when the control program of the permanent magnet synchronous motor is executed by the processor, the steps of the control method of the permanent magnet synchronous motor according to any one of claims 1 to 7 are implemented.

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