Motor and control method and device thereof, air compressor, storage medium and program product

Abstract

The invention discloses a motor control method and device, a motor, an air compressor, a storage medium and a computer program product, and the method comprises the steps: carrying out the processing of the components of the stator voltage of the motor on the alpha and beta axes and the components of the stator current of the motor on the alpha and beta axes through a preset sliding mode observer module, and carrying out the control of the motor; the components of the counter electromotive force estimated value of the motor on the alpha and beta axes are obtained; based on the components of the back electromotive force estimation value of the motor on the alpha axis and the beta axis, after a preset phase-locked loop module and a preset staged angle compensation module are used for processing, a rotor electrical angular speed estimation value of the motor and a rotor electrical angular position estimation value of the motor are obtained, and control over the motor is achieved. According to the scheme, by combining the sliding mode observer module, the phase-locked loop module and the staged angle compensation module, the rotor electrical angular velocity estimation value and the rotor electrical angular position estimation value of the motor are determined, sensorless control over the motor is achieved, and the control performance of the motor is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric machines, and particularly relates to a control method and device of an electric machine, the electric machine, an air compressor, a storage medium and a computer program product, and more particularly relates to a sliding mode observer control method and device of a super-speed air compressor electric machine, the electric machine, the air compressor, the storage medium and the computer program product. BACKGROUND

[0002] The magnetic suspension air compressor is a product applied in the field of air compressors after the development of magnetic suspension control technology in recent years. Compared with piston or screw air compressors, it generally has the advantages of low noise, oil-free environmental protection, maintenance-free, high life of core components, etc. In the system of the magnetic suspension air compressor, the electric machine (such as a permanent magnet synchronous electric machine) as a key component, its control precision is crucial to the stability of the system. The high-speed electric machine itself has high-frequency characteristics, and it is more necessary to obtain accurate electric machine rotor information (such as the position, speed, etc. of the electric machine rotor).

[0003] In the related scheme of the control method of the electric machine, a mechanical sensor needs to be installed on the electric machine to synchronously and highly accurately detect the electric machine rotor information, but the use of the mechanical sensor can accurately detect the position of the electric machine rotor, but is not suitable for the harsh air compressor working conditions of high and low temperature, strong vibration, etc. It is difficult to accurately detect the electric machine rotor information by using the mechanical sensor under the harsh working conditions of high and low temperature, strong vibration, etc., which affects the control performance of the electric machine.

[0004] The above content is only used to assist in understanding the technical solutions of the present application, and does not represent the acknowledgement of the above content as prior art. SUMMARY

[0005] The purpose of the present application is to provide a control method and device of an electric machine, the electric machine, an air compressor, a storage medium and a computer program product, to solve the problem that in the control of the electric machine (such as the permanent magnet synchronous electric machine in the magnetic suspension air compressor), the mechanical sensor is installed on the electric machine to detect the electric machine rotor information, but it is difficult to accurately detect the electric machine rotor information by using the mechanical sensor under the harsh working conditions of high and low temperature, strong vibration, etc., which affects the control performance of the electric machine, to achieve the effect of realizing the sensorless control of the electric machine by combining the sliding mode observer, the saturation function sat(), the phase-locked loop based on feedforward compensation and the phased angle compensation, and improving the control performance of the electric machine.

[0006] The application provides a control method of an electric machine, the electric machine having a stator and a rotor; the control method of the electric machine comprising: obtaining components of stator voltage of the electric machine on α and β axes and obtaining components of stator current of the electric machine on α and β axes in the case that the electric machine is running; obtaining components of back electromotive force estimation value of the electric machine on α and β axes by using a preset sliding mode observer module after processing based on the components of stator voltage of the electric machine on α and β axes and the components of stator current of the electric machine on α and β axes; obtaining rotor electric angular velocity estimation value of the electric machine and rotor electric angular position estimation value of the electric machine by using a preset phase-locked loop module and a preset phase compensation module after processing based on the components of back electromotive force estimation value of the electric machine on α and β axes; and realizing control of the electric machine according to the rotor electric angular velocity estimation value of the electric machine and the rotor electric angular position estimation value of the electric machine.

[0007] In some embodiments, a saturation function sat() is used in the preset sliding mode observer module; and / or the preset phase-locked loop module has a feedforward compensation link; wherein the feedforward compensation link is compensated by a feedforward compensation value calculated according to the following formula:

[0008] = feedforward compensation value;

[0009] wherein, , are components of back electromotive force of the electric machine on α and β axes respectively, is a permanent magnet flux on the rotor of the electric machine.

[0010] In some embodiments, the preset sliding mode observer module comprises a sliding mode observer, a saturation function sat() processing module and a filter with a preset filtering range; obtaining components of back electromotive force estimation value of the electric machine on α and β axes by using the preset sliding mode observer module after processing based on the components of stator voltage of the electric machine on α and β axes and the components of stator current of the electric machine on α and β axes comprises: obtaining stator voltage sliding mode processing value of the electric machine by processing the components of stator voltage of the electric machine on α and β axes by using the sliding mode observer; obtaining components of back electromotive force of the electric machine on α and β axes by processing the stator voltage sliding mode processing value of the electric machine and the components of stator current of the electric machine on α and β axes by using the saturation function sat() processing module; feeding back the components of back electromotive force of the electric machine on α and β axes to the sliding mode observer; and obtaining components of back electromotive force estimation value of the electric machine on α and β axes by processing the components of back electromotive force of the electric machine on α and β axes by using the filter with a preset filtering range.

[0011] In some embodiments, based on the components of the back electromotive force estimation value of the motor on the α, β axis, after processing by a preset phase-locked loop module and a preset phase compensation module, the rotor electric angular velocity estimation value of the motor and the rotor electric angular position estimation value of the motor are obtained, including: based on the components of the back electromotive force estimation value of the motor on the α, β axis, after processing by a preset phase-locked loop module, the rotor electric angular velocity estimation value of the motor and the rotor electric angular position initial value of the motor are obtained.

[0012] According to the rotor electric angular velocity estimation value of the motor, the rotor angle compensation bias value of the motor is determined; and the product value of the rotor electric angular position initial value of the motor and the rotor angle compensation bias value of the motor is taken as the rotor electric angular position estimation value of the motor.

[0013] In some embodiments, the preset phase-locked loop module has a feedforward compensation link; based on the components of the back electromotive force estimation value of the motor on the α, β axis, after processing by a preset phase-locked loop module, the rotor electric angular velocity estimation value of the motor and the rotor electric angular position initial value of the motor are obtained, including: in the preset phase-locked loop module, based on the components of the back electromotive force estimation value of the motor on the α, β axis, the rotor position error signal of the motor is determined by heterodyne method; the rotor position PI processing value of the motor is obtained by PI processing the rotor position error signal of the motor; based on the components of the back electromotive force estimation value of the motor on the α, β axis, the feedforward compensation value is obtained by processing by the feedforward compensation link, as the rotor angle compensation value of the motor; the sum value of the rotor position PI processing value of the motor and the rotor angle compensation value of the motor is taken as the rotor electric angular velocity estimation value of the motor; the rotor electric angular position initial value of the motor is obtained by integral processing the rotor electric angular velocity estimation value of the motor; wherein the feedforward compensation link is calculated according to the following formula to obtain the feedforward compensation value:

[0014] = feedforward compensation value;

[0015] wherein, , are the components of the back electromotive force of the motor on the α, β axis, is the magnetic flux of the permanent magnet on the rotor of the motor.

[0016] In some embodiments, the determining the rotor angle compensation bias value of the motor according to the rotor electrical angular velocity estimation value of the motor comprises: determining an electrical angular velocity interval to which the rotor electrical angular velocity estimation value of the motor belongs within a set electrical angular velocity range; and determining, as the compensation bias value corresponding to the electrical angular velocity interval to which the rotor electrical angular velocity estimation value of the motor belongs, a set compensation bias value corresponding to the same electrical angular velocity interval as the electrical angular velocity interval to which the rotor electrical angular velocity estimation value of the motor belongs according to a correspondence between the set electrical angular velocity interval and the set compensation bias value.

[0017] According to the above method, the motor control device of the motor having a stator and a rotor comprises: an acquisition unit configured to acquire components of a stator voltage of the motor on α and β axes and acquire components of a stator current of the motor on α and β axes in a case where the motor is running; a control unit configured to obtain components of back electromotive force estimation values of the motor on α and β axes by processing, based on the components of the stator voltage of the motor on α and β axes and the components of the stator current of the motor on α and β axes, using a preset sliding mode observer module; the control unit is further configured to obtain rotor electrical angular velocity estimation values of the motor and rotor electrical angle position estimation values of the motor by processing, based on the components of the back electromotive force estimation values of the motor on α and β axes, using a preset phase-locked loop module and a preset phase angle compensation module; and the control unit is further configured to realize control of the motor according to the rotor electrical angular velocity estimation values of the motor and the rotor electrical angle position estimation values of the motor.

[0018] In some embodiments, the switching function in the preset sliding mode observer module adopts a saturation function sat(), and / or the preset phase-locked loop module has a feedforward compensation link; the feedforward compensation link is compensated by a feedforward compensation value calculated according to the following formula:

[0019] = feedforward compensation value

[0020] wherein, , are components of back electromotive force of the motor on α and β axes, is a permanent magnet flux on the rotor of the motor.

[0021] In some embodiments, the preset sliding-mode observer module comprises a sliding-mode observer, a saturation function sat() processing module, and a preset filter with a preset filter range; the control unit, based on the components of the stator voltage of the motor on the α and β axes and the components of the stator current of the motor on the α and β axes, obtains the components of the back electromotive force estimation value of the motor on the α and β axes by processing with the preset sliding-mode observer module, comprising: processing the components of the stator voltage of the motor on the α and β axes with the sliding-mode observer to obtain the sliding-mode processed value of the stator voltage of the motor; processing the sliding-mode processed value of the stator voltage of the motor and the components of the stator current of the motor on the α and β axes with the saturation function sat() processing module to obtain the components of the back electromotive force of the motor on the α and β axes; feeding back the components of the back electromotive force of the motor on the α and β axes to the sliding-mode observer; and processing the components of the back electromotive force of the motor on the α and β axes with the preset filter with a preset filter range to obtain the components of the back electromotive force estimation value of the motor on the α and β axes.

[0022] In some embodiments, the control unit, based on the components of the back electromotive force estimation value of the motor on the α and β axes, obtains the rotor electric angular velocity estimation value of the motor and the rotor electric angular position estimation value of the motor by processing with a preset phase-locked loop module and a preset phase-division angle compensation module, comprising: obtaining the rotor electric angular velocity estimation value of the motor and the initial value of the rotor electric angular position of the motor by processing with the preset phase-locked loop module based on the components of the back electromotive force estimation value of the motor on the α and β axes; determining the rotor angle compensation bias value of the motor according to the rotor electric angular velocity estimation value of the motor; and taking the product value of the initial value of the rotor electric angular position of the motor and the rotor angle compensation bias value of the motor as the rotor electric angular position estimation value of the motor.

[0023] In some embodiments, the preset phase-locked loop module has a feedforward compensation link; the control unit, based on the components of the back electromotive force estimation value of the motor on the alpha and beta axes, obtains the rotor electric angular velocity estimation value of the motor and the initial value of the rotor electric angle position of the motor after processing by the preset phase-locked loop module, including: in the preset phase-locked loop module, based on the components of the back electromotive force estimation value of the motor on the alpha and beta axes, the rotor position error signal of the motor is determined by using the heterodyne method; the rotor position PI processing value of the motor is obtained by PI processing the rotor position error signal of the motor; based on the components of the back electromotive force estimation value of the motor on the alpha and beta axes, the feedforward compensation value is obtained by processing using the feedforward compensation link, as the rotor angle compensation value of the motor; the sum of the rotor position PI processing value of the motor and the rotor angle compensation value of the motor is taken as the rotor electric angular velocity estimation value of the motor; the initial value of the rotor electric angle position of the motor is obtained by integral processing the rotor electric angular velocity estimation value of the motor; wherein the feedforward compensation link is calculated according to the following formula to obtain the feedforward compensation value:

[0024] = feedforward compensation value;

[0025] wherein, , are the components of the back electromotive force of the motor on the alpha and beta axes, is the magnetic flux of the permanent magnet on the rotor of the motor.

[0026] In some embodiments, the control unit determines the rotor angle compensation bias value of the motor according to the rotor electric angular velocity estimation value of the motor, including: within the set electric angular velocity range, the electric angular velocity interval to which the rotor electric angular velocity estimation value of the motor belongs is determined; according to the correspondence between the set electric angular velocity interval and the set compensation bias value, the set compensation bias value corresponding to the same set electric angular velocity interval as the electric angular velocity interval to which the rotor electric angular velocity estimation value of the motor belongs is determined as the compensation bias value corresponding to the electric angular velocity interval to which the rotor electric angular velocity estimation value of the motor belongs, as the rotor angle compensation bias value of the motor.

[0027] To match the above device, the present application further provides a motor, including: the motor control device described above.

[0028] To match the above device, the present application further provides an air compressor, including: the motor control device described above, or the motor described above.

[0029] According to the method, the application provides a storage medium including a stored program, wherein the program controls the device where the storage medium is located to execute the steps of the motor control method when the program is running.

[0030] According to the method, the application provides a computer program product including a computer program, which realizes the steps of the motor control method when the program is executed by a processor.

[0031] Therefore, the application can obtain the motor rotor angular velocity and the motor rotor angular position by combining the sliding mode observer module, the phase-locked loop module and the phased angle compensation module, realize the sensorless control of the motor, and improve the control performance of the motor. 、 Stator voltage component of shaft motor 、 , 、 Stator current component of shaft motor 、 , 、 Anti-electromotive force observation component of shaft motor 、 , 、 Anti-electromotive force observation component of shaft motor 、 , Motor rotor angular velocity , Motor rotor angular position , Motor rotor angular position , Motor rotor angular position ,

[0032] The other features and advantages of the application will be described in the following description, and some will become apparent from the description, or will be understood by those skilled in the art from the practice of the application.

[0033] The technical solutions of the present application are described in further detail below with reference to the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Flowchart of an embodiment of the method for controlling the motor of the present application;

[0035] Figure 2 Flowchart of an embodiment of the method for obtaining the components of the back electromotive force estimate of the motor in the α, β axes;

[0036] Figure 3 Flowchart of an embodiment of the method for obtaining the rotor electrical angular velocity estimate of the motor and the rotor electrical angular position estimate of the motor;

[0037] Figure 4 Flowchart of an embodiment of the method for obtaining the rotor electrical angular velocity estimate of the motor and the initial value of the rotor electrical angular position of the motor;

[0038] Figure 5 Flowchart of an embodiment of the method for determining the rotor angular compensation bias value of the motor based on the rotor electrical angular velocity estimate of the motor;

[0039] Figure 6 Structural diagram of an embodiment of the motor control device of the present application;

[0040] Figure 7 Principle diagram of a sliding mode observer;

[0041] Figure 8 Principle diagram of a saturation function;

[0042] Figure 9 Structural diagram of a phase-locked loop (PLL) system based on feedforward compensation;

[0043] Figure 10 Structural diagram of a mathematical model of a feedforward phase-locked loop (PLL) system;

[0044] Figure 11 Precise phased angle compensation formula, i.e., correspondence table between speed range and angle compensation, i.e., Table 1.

[0045] In the embodiments of the present application, the reference signs in the accompanying drawings are as follows:

[0046] 102 - acquisition unit; 104 - control unit. DETAILED DESCRIPTION

[0047] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in connection with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0048] It is considered that, in the control of the motor (such as the permanent magnet synchronous motor in the magnetic suspension air compressor), the motor rotor information is detected by installing a mechanical sensor on the motor, but it is difficult to accurately detect the motor rotor information by using the mechanical sensor under the working conditions of high and low temperature, strong vibration and other harsh conditions, which affects the control performance of the motor. The sensorless control (i.e. control without mechanical sensor) can well overcome the above shortcomings, estimate the motor rotor position by collecting parameters related to the motor rotor position, simplify the structure of the motor while reducing the cost, and the sliding mode controller combines the advantages of sliding mode control and state observer, and can realize high-precision speed control of the motor.

[0049] However, the sliding mode observer (i.e. state observer based on sliding mode control) in the related scheme has the problem of chattering, which affects the control accuracy, increases the energy loss of the motor, and may cause system oscillation or instability. The sliding mode controller (SMC) and the sliding mode observer (SMO) are two very important technologies in control theory, which are based on the sliding mode variable structure control (VSC) theory, and have the advantages of strong robustness, insensitivity to parameter uncertainty and external disturbance. The core idea of sliding mode control is to design a switching surface (such as sliding surface), so that the state trajectory of the system reaches the switching surface in a limited time, and slides along the surface, and finally tends to the desired equilibrium point of the system. The sliding mode observer is a state observer based on sliding mode control, which takes the difference between the real system state and the virtual system state as a new state, and performs sliding mode control on the motor.

[0050] The sliding mode observer (SMO) estimates the speed of the motor according to the voltage and current parameters of the motor, the difference between the measured current and the estimated current constitutes a sliding mode surface, and the control function makes the system frequently switch on the sliding mode surface, which has the characteristics of simple implementation and strong robustness. However, in the related scheme, the sliding mode observer obtains the estimated value of the motor back electromotive force through a simple first-order low-pass filter, and then obtains the motor rotor position and motor rotor speed information according to the relationship between the estimated motor back electromotive force and the motor rotor position; in actual sliding mode control, due to the inherent inertia of the traditional sliding film observer, the time and space delay of the switching function, and the system error and other reasons, the motor rotor motion point will not smoothly move on the sliding mode surface after reaching the sliding mode area, but will shuttle back and forth on the sliding mode surface, forming a sawtooth-shaped motion trajectory, which is the "chattering" phenomenon of the motor control system.

[0051] Therefore, the scheme of the present application proposes a motor control method, specifically a sliding mode observer control method for a super-high-speed air compressor motor, which estimates the motor rotor position by collecting parameters related to the motor rotor position and using a sliding mode observer (SMO) to achieve high-precision speed sensorless control of the motor. Among them, for the sliding mode observer (SMO), a saturation function is used instead of the sign function of the sliding mode observer (SMO) in the related scheme as a switching function, a phase-locked loop method based on feedforward compensation is used instead of the arctangent function of the sliding mode observer (SMO) in the related scheme, and precise phased angle compensation is used to eliminate the delay effect caused by the low-pass filter of the sliding mode observer (SMO), thereby improving the control performance of the motor.

[0052] According to an embodiment of the present application, a motor control method is provided, as shown in Figure 1 The flowchart of an embodiment of the method of the present application is shown. The motor has a stator and a rotor; in the scheme of the present application, as shown in Figure 1 The motor control method comprises steps S110 to S140.

[0053] At step S110, under the condition that the motor is running, the components of the stator voltage of the motor on the α and β axes are obtained, and the components of the stator current of the motor on the α and β axes are obtained, and of course, the observed values of the stator current of the motor on the α and β axes can also be obtained to calculate using formula (7); wherein the components of the stator voltage of the motor on the α and β axes are as shown in 、 Stator voltage component of the motor on the α and β axes 、 The components of the stator current of the motor on the α and β axes are as shown in 、 Stator current component of the motor on the α and β axes 、 , the observed value of the stator current of the motor in the components of the α, β axes is as follows 、 Observed value of stator current of motor in components of α, β axes 、 .

[0054] At step S120, based on the components of the stator voltage of the motor in the α, β axes and the components of the stator current of the motor in the α, β axes, the estimated value of the back electromotive force of the motor in the components of the α, β axes is obtained after processing by using a preset sliding mode observer module; wherein the estimated value of the back electromotive force of the motor in the components of the α, β axes is as follows 、 Observed value of back electromotive force in components of α, β axes 、 .

[0055] At step S130, based on the estimated value of the back electromotive force of the motor in the components of the α, β axes, the estimated value of the rotor electric angular velocity of the motor and the estimated value of the rotor electric angular position of the motor are obtained after processing by using a preset phase-locked loop module and a preset phase compensation module; wherein the estimated value of the rotor electric angular velocity of the motor is as follows , and the estimated value of the rotor electric angular position of the motor is as follows .

[0056] At step S140, the control of the motor is realized according to the estimated value of the rotor electric angular velocity of the motor and the estimated value of the rotor electric angular position of the motor.

[0057] The scheme of the application proposes a sliding mode observer scheme of a super-high-speed air compressor motor, which estimates the motor rotor position by using a sliding mode observer (SMO) to realize high-precision speed sensorless control of the motor by collecting parameters related to the motor rotor position; wherein a low-pass filter (LPF) is used in the sliding mode observer (SMO) to filter high-frequency harmonics in the motor back electromotive force; after the motor rotor electric angular position and angular velocity are extracted by a phase-locked loop (PLL) system, the delay effect caused by the low-pass filter must be eliminated, and precise phase compensation is adopted to eliminate the delay effect caused by the low-pass filter in the sliding mode observer, so as to accelerate the response speed of the system, reduce the observation error of the observer, enhance the timeliness of the motor control system, and improve the control performance of the motor.

[0058] In some embodiments, the preset switching function in the sliding mode observer module adopts a saturation function sat(), that is, in the sliding mode observer, the saturation function sat() is used instead of the sign function sgn() as the switching function. And / or, the preset phase-locked loop module has a feedforward compensation link; wherein the feedforward compensation link is compensated by a feedforward compensation value calculated according to the following formula:

[0059] = feedforward compensation value

[0060] wherein, , are components of back electromotive force of the motor on the α and β axes respectively, is the magnetic flux of the permanent magnet on the rotor of the motor.

[0061] The scheme of the application proposes a sliding mode observer scheme for a super-speed air compressor motor, which estimates the motor rotor position by collecting parameters related to the motor rotor position and using a sliding mode observer (SMO), to realize high-precision speed sensorless control of the motor. For the sliding mode observer (SMO), a saturation function is used instead of the sign function in the related scheme as the switching function, which significantly reduces the chattering phenomenon in the sliding mode control. The phase-locked loop method based on feedforward compensation is used instead of the arctangent function in the related scheme, which improves the observation accuracy and system convergence speed. Precise phased angle compensation is used to eliminate the delay effect caused by the low-pass filter and enhance the timeliness of the motor control system, thereby improving the control performance of the motor.

[0062] In some embodiments, the preset sliding mode observer module includes a sliding mode observer, a saturation function sat() processing module, and a filter with a preset filter range, such as a low-pass filter. In step S120, based on the components of the stator voltage of the motor on the α and β axes and the components of the stator current of the motor on the α and β axes, the preset sliding mode observer module is used to process to obtain the specific process of the components of the back electromotive force estimation value of the motor on the α and β axes, as shown in the following exemplary description.

[0063] The following will be further described with reference to the embodiment flowchart of the method of the application shown in Figure 2 to further illustrate the specific process of obtaining the components of the back electromotive force estimation value of the motor on the α and β axes in step S120, which includes steps S210 to S230.

[0064] In step S210, the components of the stator voltage of the motor on the α and β axes are processed by the sliding mode observer to obtain the sliding mode processing value of the stator voltage of the motor.

[0065] Step S220, the stator voltage sliding mode processing value of the motor and the components of the stator current of the motor on the α, β axis are processed by the saturation function sat() processing module to obtain the components of the back electromotive force of the motor on the α, β axis; wherein the components of the back electromotive force of the motor on the α, β axis are as follows 、 Back electromotive force component of shaft motor 、 .

[0066] Step S230, the components of the back electromotive force of the motor on the α, β axis are fed back to the sliding mode observer; and the components of the back electromotive force of the motor on the α, β axis are processed by the filter of the preset filtering range to obtain the components of the back electromotive force estimation value of the motor on the α, β axis.

[0067] In the scheme of the application, it is known from the mathematical model of the surface-mounted permanent magnet synchronous motor that, in the two-phase stationary coordinate system, the current equation of the permanent magnet synchronous motor is:

[0068] (1).

[0069] Among them, .

[0070] In the formula, 、 are respectively 、 Stator current components of shaft motor 、 are respectively 、 Stator voltage components of shaft motor 、 are respectively motor stator resistance and inductance 、 are respectively 、 Back electromotive force components of shaft motor is the motor rotor electrical angle position is the motor rotor electrical angular velocity is the permanent magnet flux on the motor rotor.

[0071] By constructing a suitable sliding mode observer, the estimated 、 , the motor rotor electrical angle position information can be obtained. The operation is to construct an observer model based on the actual current mathematical model of the permanent magnet synchronous motor, and construct a mathematical model taking the motor stator current as a variable, which is convenient for subsequent extraction of the position information of the motor. Mechanical sensors are not suitable for harsh air compressor working conditions such as high and low temperature, strong vibration, etc. The observer model constructed by taking the motor stator current as a variable is:

[0072] (2).

[0073] wherein, , are respectively , the stator current observation value component of the motor, , are respectively the motor stator resistance and inductance, , is , the sliding mode control law of the shaft.

[0074] When the sliding film observer model and the actual motor model tend to be consistent, the size of the extended back electromotive force in the sliding film observer is the size of the extended back electromotive force of the motor, and the size of the motor rotor electric angle position can be obtained according to the value. When the sliding film observer model and the actual motor model tend to be consistent, the size of the extended back electromotive force in the sliding film observer is the size of the extended back electromotive force of the actual motor, and the motor position information needs to be extracted therefrom.

[0075] The sliding surface is a hyperplane in the sliding mode observer about the estimation error, and the function of the sliding surface is to guide the state estimation error x to quickly approach and "slide" on the hyperplane, so as to realize accurate estimation of the true state. The sliding surface is selected as:

[0076] (3).

[0077] wherein, , are respectively , the error value of the motor stator current observation value and the actual value of the shaft, , are respectively , the stator current observation value component of the motor, , are respectively , the stator current component of the motor.

[0078] The difference between the state current observation value and the actual value is taken as a new state variable, and they are subjected to sliding mode control. When the sliding mode motion is made on the sliding surface , the above (1), (2), (3) can be obtained:

[0079] (4).

[0080] Equation (4) is the equation of the extended back EMF when the sliding mode motion is obtained on the sliding surface by the sliding mode control of the difference between the observed value and the actual value of the state current.

[0081] Figure 8 The principle diagram of the saturation function. In order to suppress the effective chattering phenomenon, the saturation function sat() is used to replace the original switching function sgn() function, and the principle diagram of the saturation function is shown in detail in Figure 8 .

[0082] (5).

[0083] In the formula, is the boundary layer of the saturation function, is the error value of the observed value and the actual value of the motor stator current of the axis. The value needs to be adjusted according to the specific operation of the motor and the observation information of the observer during the debugging process; The saturation function of the formula is the same, only one is for the axis and the other is for the axis.

[0084] The sliding mode control law is selected as:

[0085] (6).

[0086] In the formula, , are the sliding mode switching functions of the , axis, K is the sliding mode gain, is the saturation function.

[0087] Therefore, the extended back EMF observed by the sliding mode observer is:

[0088] (7).

[0089] In the formula, , are the observed value components of the back EMF of the , axis, , are the error values of the observed value and the actual value of the motor stator current of the , axis, K is the sliding mode gain. The value of K generally needs to be able to guarantee the stability of the sliding mode observer, so it needs to be determined according to the Lyapunov function. The extended back EMF obtained according to equation (7) is a discontinuous high-frequency switching signal, which cannot be directly substituted into Solving this problem typically requires adding an external low-pass filter. The result obtained here is the observed value of the extended back electromotive force. , The function of the low-pass filter is to filter out the high-frequency harmonics in the observed extended back electromotive force. The high-frequency harmonics will affect the system response speed; as can be seen from equations (3) and (2), , Components of stator current observation of shaft motor , It is unknown and needs to be investigated. , According to the calculation, the stator voltage value is required.

[0090] In related schemes, the sliding mode observer (SMO) uses a sign function as the switching function. This sign function is a discontinuous step function, which can cause severe chattering when the system undergoes high-frequency switching, significantly reducing the accuracy and stability of the motor control system. In the solution of this invention, to suppress the chattering problem of the SMO, a saturated function is used instead of the sign function in related schemes. The saturated function, through smooth transition, avoids abrupt switching of the sign function, thereby significantly reducing high-frequency chattering in sliding mode control. In the solution of this invention, a saturated function is used instead of the sign function in related schemes. The saturated function, through smooth transition, avoids abrupt switching of the sign function, thereby significantly reducing high-frequency chattering in sliding mode control.

[0091] In some embodiments, the specific process of obtaining the estimated rotor electric angular velocity and the estimated rotor electric angular position of the motor by processing the estimated back electromotive force of the motor in step S130 based on the components of the back electromotive force of the motor in the α and β axes using a preset phase-locked loop module and a preset staged angle compensation module is described in the following exemplary description.

[0092] The following is combined Figure 3 The schematic diagram shows an embodiment of the method of the present invention for obtaining the estimated value of the rotor electrical angular velocity and the estimated value of the rotor electrical angle position of the motor. It further illustrates the specific process of obtaining the estimated value of the rotor electrical angular velocity and the estimated value of the rotor electrical angle position of the motor in step S130, including steps S310 to S330.

[0093] Step S310: Based on the components of the back electromotive force estimate of the motor along the α and β axes, the estimated rotor electric angular velocity and the initial value of the rotor electric angle position of the motor are obtained after processing by a preset phase-locked loop module; wherein, the initial value of the rotor electric angle position of the motor is the same as the rotor electric angle position extracted by the phase-locked loop. .

[0094] Step S320, determining a rotor angle compensation bias value of the motor according to the rotor electrical angular velocity estimation value of the motor; wherein the rotor angle compensation bias value of the motor is as a compensation bias .

[0095] Step S330, determining a rotor electrical angle position estimation value of the motor according to the rotor electrical angle position initial value of the motor and the rotor angle compensation bias value of the motor, specifically: taking a product value of the rotor electrical angle position initial value of the motor and the rotor angle compensation bias value of the motor as the rotor electrical angle position estimation value of the motor.

[0096] Figure 7 is a schematic diagram of the principle of the sliding mode observer. The sliding mode control is to use the voltage and current of the permanent magnet synchronous motor as the input, to obtain the estimated back electromotive force of the motor through the electromagnetic theory of the motor and the sliding mode algorithm, to extract the motor rotor electrical angle position and angular velocity of the motor from the estimated back electromotive force, and the principle block diagram is as shown in Figure 7 As shown in Figure 7 , , are , axis motor stator voltage components, , input into the sliding film observer; , are , axis motor stator current components, the difference between the first value output by the sliding film observer and is input into the first input end of the saturation function sat() module, and the difference between the second value output by the sliding film observer and is input into the second input end of the saturation function sat() module; , are , axis motor back electromotive force components, the first output end of the saturation function sat() module outputs , and the second output end of the saturation function sat() module outputs ; the output by the first output end of the saturation function sat() module is input into the first input end of the low-pass filter, and the output by the first output end of the saturation function sat() module is also fed back to the first feedback end of the sliding film observer; the output by the second output end of the saturation function sat() module is input into the second input end of the low-pass filter, and the output by the second output end of the saturation function sat() module is also fed back to the second feedback end of the sliding film observer; , are respectively , axis back electromotive force observation value component, the first output end of the low pass filter outputs , the second output end of the low pass filter outputs , the first output end of the low pass filter outputs is input to the first input end of the phase-locked loop module based on feedforward compensation, and the second output end of the low pass filter outputs is input to the second input end of the phase-locked loop module based on feedforward compensation. is the motor rotor electrical angle position extracted by the phase-locked loop, is the motor rotor angular velocity extracted by the phase-locked loop, the first output end of the phase-locked loop module based on feedforward compensation outputs , the first output end of the phase-locked loop module based on feedforward compensation outputs ; is the motor rotor electrical angle position, is the compensation bias, and are multiplied by the multiplier to obtain . The first value output by the sliding mode observer refers to in formula (2), and is the axis stator current observation value; the second value output by the sliding mode observer refers to in formula (2), and is the axis stator current observation value. The sliding mode observation scheme based on the super-high-speed air compressor motor provided by the scheme avoids the sharp switching of the sign function, significantly reduces the high-frequency jitter in the sliding mode control, maintains the stability and tracking performance of the system in the presence of external disturbances, reduces the observation error of the sliding mode observer, improves the observation accuracy, and enhances the robustness of the system.

[0097] In some embodiments, the preset phase-locked loop module has a feedforward compensation link.

[0098] The specific process of obtaining the rotor electrical angular velocity estimate value of the motor and the initial value of the rotor electrical angle position of the motor in step S310 based on the components of the back electromotive force estimate value of the motor in the α and β axes after processing by the preset phase-locked loop module is described below with reference to the following exemplary description.

[0099] The following describes an embodiment flowchart of the method of the application shown in Figure 4 to further illustrate the specific process of obtaining the rotor electrical angular velocity estimate value of the motor and the initial value of the rotor electrical angle position of the motor in step S310, which includes steps S410 to S450.

[0100] Step S410: In the preset phase-locked loop module, based on the components of the back electromotive force estimate of the motor on the α and β axes, the rotor position error signal of the motor is determined using the heterodyne method; wherein, the rotor position error signal of the motor is the same as the rotor position error signal of the motor obtained by the heterodyne method. .

[0101] Step S420: The rotor position error signal of the motor is processed by PI to obtain the PI processed value of the rotor position of the motor.

[0102] Step S430: Based on the components of the back electromotive force estimate of the motor in the α and β axes, the feedforward compensation circuit is used to process the data to obtain the feedforward compensation value, which is then used as the rotor angle compensation value of the motor.

[0103] Step S440: The sum of the rotor position PI processing value of the motor and the rotor angle compensation value of the motor is used as the estimated value of the rotor electric angular velocity of the motor.

[0104] Step S450: The estimated value of the rotor electric angular velocity of the motor is integrated to obtain the initial value of the rotor electric angular position of the motor.

[0105] The feedforward compensation element is calculated using the following formula to obtain the feedforward compensation value:

[0106] =Feedforward compensation value;

[0107] in, , These are the components of the back electromotive force of the motor along the α and β axes, respectively. The permanent magnet flux linkage on the rotor of the motor.

[0108] Figure 9 This is a schematic diagram of a phase-locked loop (PLL) system based on feedforward compensation. Figure 9 As shown, , They are respectively , The components of the back electromotive force observation, - The value output after the first multiplier is the same as... The difference between the output values ​​after the second multiplier, multiplied by 1 / ( The motor rotor position error signal is obtained after the module. ; The PI-processed value is obtained after PI processing. , Through feedforward / The module processing value is obtained after the feedforward link processing. The sum of the PI processing value and the feedforward link processing value is the estimated value of the motor rotor electric angle speed . The estimated value of the motor rotor electric angle position is obtained after the 1 / s module processing . After the cos() module processing, feedback to the first multiplier, After the sin() module processing, feedback to the second multiplier. The motor rotor position error signal obtained by the heterodyne method The PI processing value obtained after the PI tracker is the estimated value of the motor rotor angular speed. The motor rotor angular speed in the traditional sliding mode observer is the value after the PI tracker. In the present application, in order to quickly make the estimated position angle of the rotor close to the actual position angle and make the phase-locked loop system converge as soon as possible, a feedforward link is added. The value is the estimated value of the motor rotor angular speed originally extracted by the phase-locked loop system without the feedforward compensation link. In the present application, the feedforward compensation link output value is added to the value to obtain the estimated value of the motor rotor angular speed of the improved phase-locked loop system. Figure 9 The present application can reflect the improvements in the present application, that is, the use of a phase-locked loop (PLL) structure to calculate motor rotor information, and the addition of a feedforward link in the phase-locked loop model. The phase-locked loop (PLL) system based on feedforward compensation effectively reduces the chattering phenomenon in sliding mode control, reduces the observation error of the observer, and improves the observation accuracy and system convergence speed.

[0109] In order to avoid the error caused by the arctangent function and make the estimated electric angle position of the motor rotor close to the actual electric angle position, thereby making the phase-locked loop quickly converge, a phase-locked loop (PLL) system based on feedforward is used to extract motor rotor electric angle position information such as the estimated value of the motor rotor electric angular speed and the estimated value of the motor rotor electric angle position , as shown in Figure 9 The motor rotor position error signal obtained by the heterodyne method The motor rotor angular speed can be estimated after the PI tracker , and the motor rotor electric angle position can be integrated to obtain Heterodyne method is an interference measurement method, which changes the frequency of the reference signal to produce a frequency difference between the reference signal and the measurement signal, and the phase of the interference signal contains the phase modulation term (carrier) and the measured term after the interference of the reference signal and the measurement signal. The phase of the measured quantity can be obtained by demodulating the interference signal. This method of introducing a carrier in the phase of the interference signal is called heterodyne method. Compared with homodyne method, heterodyne method measures the measured physical quantity by demodulating the interference signal, and the change of the interference signal strength can be ignored, so as to improve the interference measurement precision. As shown in Figure 9 ,

[0110] (8) ;

[0111] = (9).

[0112] The above formula (8) obtains the mathematical model of the feedforward phase-locked loop (i.e. PLL) system as shown in Figure 10 , Figure 10 is a structural diagram of the mathematical model of the feedforward phase-locked loop (i.e. PLL) system. As shown in Figure 10 , The value after s module processing, and the difference value of and The sum value of the value after (k p +k i / s) module processing is used as the motor rotor angular velocity ; The motor rotor electric angle position is obtained after 1 / s module processing. It can be obtained that: Figure 10

[0113] (10).

[0114] In the formula, is the extracted motor rotor electric angle position, is the extracted motor rotor angular velocity, is the proportional gain of the PI controller, is the integral gain of the PI controller. is the rotor electric angle estimation position reference value, is the rotor estimated electric angular velocity reference value, and s is a complex variable in Laplace transform.

[0115] Therefore, the closed-loop transfer function of the feedforward phase-locked loop (i.e. PLL) system is:

[0116] (11).

[0117] ​From equation (3), it can be seen that the output of the system completely replicates the change of the input.

[0118] The sliding mode observer (SMO) in the related scheme needs to use an arctangent function when calculating the motor rotor speed and position, which has a large amount of calculation and can aggravate the chattering phenomenon of the system, thereby affecting the measurement accuracy of the observer. Therefore, in the scheme of the present application, a phase-locked loop (PLL) structure is used to calculate the motor rotor information, so as to avoid a large amount of calculation and reduce the chattering phenomenon of the system.

[0119] The convergence speed of the saturation function in the calculation of the sliding mode observer (SMO) in the related scheme is slow, and the convergence speed of the observed current error is correspondingly reduced, thereby slowing down the response speed of the system. Therefore, in the scheme of the present application, a feedforward link is added to the phase-locked loop model, so that the estimated electric angle position of the motor rotor is close to the actual electric angle position, the observation accuracy is improved, the phase-locked loop (PLL) system converges as soon as possible, the response speed is accelerated, and the tracking performance of the system is maintained.

[0120] In some embodiments, the specific process of determining the rotor angle compensation bias value of the motor according to the rotor electric angle speed estimation value of the motor in step S320 is described below.

[0121] The specific process of determining the rotor angle compensation bias value of the motor according to the rotor electric angle speed estimation value of the motor in step S320 is described below. Figure 5 The specific process of determining the rotor angle compensation bias value of the motor according to the rotor electric angle speed estimation value of the motor in step S320 is described below.

[0122] In step S510, the electric angle speed estimation value of the motor belongs to the electric angle speed interval is determined within the set electric angle speed range.

[0123] In step S520, according to the correspondence between the set electric angle speed interval and the set compensation bias value, the set compensation bias value corresponding to the same set electric angle speed interval as the electric angle speed estimation value of the motor belongs to is determined as the compensation bias value corresponding to the electric angle speed estimation value of the motor, as the rotor angle compensation bias value of the motor.

[0124] After the phase-locked loop (PLL) system extracts the electric angle position and speed of the motor rotor, the delay effect caused by the low-pass filter must be eliminated. This can be achieved by adding a compensation bias to the uncompensated .

[0125] (12).

[0126] In the formula, This refers to the electrical angle position of the motor rotor. The electrical angle position of the motor rotor extracted by the phase-locked loop. To compensate for the offset, precise, staged angle compensation is performed for different speed ranges. This angle compensation must be precisely adjusted to suit other motor models. In this invention, the angle compensation is divided into nine angular velocity ranges. Each angular velocity range has its own slope of change, as detailed below. Figure 11 . Figure 11 To accurately determine the phased angle compensation formula, i.e., the correspondence between the speed range and angle compensation (Table 1), in... Figure 11 In Chinese, Omega is... Theta_offset is . This is a compensation coefficient and has no unit.

[0127] In Table 1: When , ;

[0128] when , ;

[0129] when , ;

[0130] when , ;

[0131] when , ;

[0132] when , ;

[0133] when , ;

[0134] when , ;

[0135] when , .

[0136] The low pass filter (LPF) is used in the sliding mode observer (SMO) in the related scheme to filter the high-frequency harmonic in the motor back electromotive force, which can cause the delay problem of the motor control system, and the delay phenomenon is particularly obvious in the high-speed motor control system, which reduces the system response speed and affects the timeliness of the motor control system.

[0137] The principle diagram of the sliding mode observer improved based on the related scheme in the scheme of the application is shown in Figure 7 , and the sliding mode observer analysis step is also derived according to the principle block diagram shown in Figure 7 The following formulas are listed according to the analysis and derivation of the sliding mode observer analysis step. Formulas (1)-(4) are the motor mathematical model and the sliding mode observer model, formula (5) is the formula of the saturation function used, formula (6) is the sliding mode control law formula in the sliding mode observer after the saturation function is used to replace the switching function in the related scheme, formula (7) is the observed extended back electromotive force formula obtained by substituting (6) into (4), formulas (8)-(9) are mathematical formula models derived according to Figure 9 , formulas (10)-(11) are mathematical models and system transfer functions of the phase-locked loop (PLL) system based on feedforward, and formula (12) is the calculation formula of the phased precise compensation angle, which has different compensation biases in different speed sections.

[0138] The scheme of the application proposes a sliding mode observer scheme for a super-high-speed air compressor motor, which is not only applied in the air compressor industry, but also applicable to other super-high-speed motor application industries for adjusting the angle compensation.

[0139] The technical scheme of the embodiment is adopted, in the control of the motor (such as a super-high-speed air compressor motor), under the condition of motor operation, according to 、 the stator voltage component of the motor 、 , and 、 the stator current component of the motor 、 , after being processed by the sliding film observer, the saturation function sat(), and the low pass filter, the 、 motor back electromotive force observation value component 、 is obtained; the phase-locked loop based on feedforward compensation (i.e., the phase-locked loop system with a feedforward compensation link) is used to obtain 、 motor back electromotive force observation value component 、 extracting motor rotor angular velocity , and motor rotor electrical angular position ; according to motor rotor electrical angular position , according to motor rotor angular velocity the interval, angular compensation is performed to obtain motor rotor electrical angular position ; further according to motor rotor angular velocity , and motor rotor electrical angular position , control of the motor is realized; thus, by combining the sliding mode observer, the saturation function sat(), the phase-locked loop based on feedforward compensation, and the phased angular compensation, sensorless control of the motor is realized, and the control performance of the motor is improved.

[0140] According to the embodiment of the present application, a control device of a motor corresponding to the control method of the motor is also provided. Referring to the structural schematic diagram of an embodiment of the device of the present application shown in Figure 6 , the control device of the motor comprises an acquisition unit 102 and a control unit 104. Figure 6

[0141] The acquisition unit 102 is configured to acquire the components of the stator voltage of the motor on the α and β axes and acquire the components of the stator current of the motor on the α and β axes when the motor is running, and of course, the observation value of the stator current of the motor on the α and β axes can also be acquired to calculate by using formula (7); wherein the components of the stator voltage of the motor on the α and β axes are as shown in 、 components of stator voltage of motor on α and β axes 、 the components of the stator current of the motor on the α and β axes are as shown in 、 components of stator current of motor on α and β axes 、 the components of the observation value of the stator current of the motor on the α and β axes are as shown in 、 components of observation value of stator current of motor on α and β axes 、 The specific functions and processes of the acquisition unit 102 are described in step S110.

[0142] ​The control unit 104 is configured to obtain the components of the back electromotive force estimation value of the motor on the alpha and beta axes by processing the components of the stator voltage of the motor on the alpha and beta axes and the components of the stator current of the motor on the alpha and beta axes by using a preset sliding mode observer module; wherein the components of the back electromotive force estimation value of the motor on the alpha and beta axes are , Back electromotive force observation value component on the axis , The specific functions and processes of the control unit 104 are described in step S120.

[0143] The control unit 104 is further configured to obtain the rotor electric angular velocity estimation value of the motor and the rotor electric angular position estimation value of the motor by processing the components of the back electromotive force estimation value of the motor on the alpha and beta axes by using a preset phase-locked loop module and a preset phase angle compensation module; wherein the rotor electric angular velocity estimation value of the motor is an estimation value of the motor rotor electric angular velocity , and the rotor electric angular position estimation value of the motor is an estimation value of the motor rotor electric angular position The specific functions and processes of the control unit 104 are described in step S130.

[0144] The control unit 104 is further configured to realize the control of the motor according to the rotor electric angular velocity estimation value of the motor and the rotor electric angular position estimation value of the motor. The specific functions and processes of the control unit 104 are described in step S140.

[0145] The scheme of the application proposes a sliding mode observer scheme of a super-high-speed air compressor motor, which estimates the motor rotor position by using a sliding mode observer (SMO) to realize high-precision speed sensorless control of the motor by collecting parameters related to the motor rotor position; wherein a low-pass filter (LPF) is used in the sliding mode observer (SMO) to filter high-frequency harmonics in the back electromotive force of the motor; after the phase-locked loop (PLL) system extracts the motor rotor electric angular position and angular velocity, the delay effect caused by the low-pass filter must be eliminated, and precise phase angle compensation is adopted to eliminate the delay effect caused by the low-pass filter in the sliding mode observer and the like, so as to speed up the system response speed, reduce the observation error of the observer, enhance the timeliness of the motor control system, and improve the control performance of the motor.

[0146] In some embodiments, the preset switching function in the sliding mode observer module adopts a saturation function sat(); that is, in the sliding mode observer, a saturation function sat() is used instead of a sign function sgn() as the switching function. And / or, the preset phase-locked loop module has a feedforward compensation link; wherein the feedforward compensation link is compensated by a feedforward compensation value calculated according to the following formula:

[0147] = feedforward compensation value;

[0148] wherein, , are components of back electromotive force of the motor on the α and β axes respectively, is a permanent magnet flux on the rotor of the motor.

[0149] The scheme of the present application proposes a sliding mode observer scheme for a super-high-speed air compressor motor, estimates the motor rotor position by collecting parameters related to the motor rotor position and using a sliding mode observer (SMO), and realizes high-precision speed sensorless control of the motor. For the sliding mode observer (SMO), a saturation function is used instead of a sign function in related schemes as the switching function, which significantly reduces the chattering phenomenon in sliding mode control. The phase-locked loop method based on feedforward compensation is used instead of the arctangent function in related schemes to improve the observation accuracy and system convergence speed. Precise phased angle compensation is used to eliminate the delay effect caused by low-pass filters and the like, enhance the timeliness of the motor control system, and improve the control performance of the motor.

[0150] In some embodiments, the preset sliding mode observer module includes a sliding mode observer, a saturation function sat() processing module, and a filter with a preset filter range, such as a low-pass filter. The control unit 104, based on the components of the stator voltage of the motor on the α and β axes and the components of the stator current of the motor on the α and β axes, uses the preset sliding mode observer module to process and obtain the components of the back electromotive force estimate of the motor on the α and β axes, including:

[0151] The control unit 104 is specifically further configured to process the components of the stator voltage of the motor on the α and β axes through the sliding mode observer to obtain the sliding mode processing value of the stator voltage of the motor. The specific functions and processing of the control unit 104 are also referred to step S210.

[0152] The control unit 104 is specifically further configured to process the sliding mode processing value of the stator voltage of the motor and the components of the stator current of the motor on the α and β axes through the saturation function sat() processing module to obtain the components of the back electromotive force of the motor on the α and β axes; wherein the components of the back electromotive force of the motor on the α and β axes are as follows: 、 Back electromotive force component of shaft motor 、 The specific functions and processes of the control unit 104 are also described in step S220.

[0153] The control unit 104 is specifically configured to feed back the components of the back electromotive force of the motor on the α and β axes to the sliding mode observer, and to process the components of the back electromotive force of the motor on the α and β axes through the filter of the preset filtering range to obtain the estimated value of the back electromotive force of the motor on the α and β axes. The specific functions and processes of the control unit 104 are also described in step S230.

[0154] In the scheme of the application, it is known from the mathematical model of the surface-mounted permanent magnet synchronous motor that, in the two-phase stationary coordinate system, the current equation of the permanent magnet synchronous motor is:

[0155] (1).

[0156] Among them, .

[0157] In the formula, 、 are 、 the stator current components of the shaft motor, 、 are 、 the stator voltage components of the shaft motor, 、 are the motor stator resistance and inductance, 、 are 、 the back electromotive force components of the shaft motor, is the motor rotor electrical angle position, is the motor rotor electrical angular velocity, is the permanent magnet flux on the motor rotor.

[0158] By constructing a suitable sliding mode observer, the estimated 、 , the motor rotor electrical angle position information can be obtained. This operation is based on the actual current mathematical model of the permanent magnet synchronous motor to construct an observer model, and the motor stator current is used as a variable to construct a mathematical model, which is convenient for subsequent extraction of the position information of the motor. Mechanical sensors are not suitable for harsh air compressor working conditions such as high and low temperature, strong vibration, etc. The observer model constructed by taking the motor stator current as a variable is:

[0159] (2).

[0160] wherein, , are , the stator current observation value component of the shaft motor, , are the motor stator resistance and inductance, , , the sliding mode control law of the shaft.

[0161] When the sliding film observer model and the actual motor model tend to be consistent, the size of the extended back electromotive force in the sliding film observer is the size of the extended back electromotive force of the motor, and the size of the motor rotor electric angle position can be obtained according to the value. When the sliding film observer model and the actual motor model tend to be consistent, the size of the extended back electromotive force in the sliding film observer is the size of the extended back electromotive force of the actual motor, and the motor position information needs to be extracted therefrom.

[0162] The sliding surface is a hyperplane in the sliding mode observer about the estimation error, and the function of the sliding surface is to guide the state estimation error x to quickly approach and "slide" on the hyperplane, so as to realize accurate estimation of the true state. The sliding surface is selected as:

[0163] (3).

[0164] wherein, , is , the error value of the motor stator current observation value and the actual value of the shaft, , are , the stator current observation value component of the shaft motor, , are , the stator current component of the shaft motor.

[0165] The difference between the state current observation value and the actual value is taken as a new state variable, and they are subjected to sliding mode control. When sliding mode motion is made on the sliding surface , the following (1), (2), (3) can be obtained:

[0166] (4).

[0167] Equation (4) is the equation of the extended back electromotive force obtained by sliding mode motion on the sliding surface when the sliding mode control of the difference between the state current observation value and the actual value is performed.

[0168] ​Figure 8 This is a schematic diagram of the saturation function. To suppress effective chattering, the saturation function `sat()` is used. See the schematic diagram of the saturation function for details. Figure 8 This will replace the original on / off function sgn(), that is:

[0169] (5).

[0170] In the formula, It is the boundary layer of the saturation function. for The error between the observed and actual values ​​of the motor stator current on the shaft.

[0171] Selecting a sliding mode control law:

[0172] (6).

[0173] In the formula, , They are respectively , The axis sliding mode switching function, where K is the sliding mode gain. It is a saturation function.

[0174] Therefore, the extended back electromotive force observed by the synovial observer is obtained as follows:

[0175] (7).

[0176] In the formula, , They are respectively , The components of the back electromotive force observation on the axis, , for , The error between the observed and actual values ​​of the motor stator current on the shaft, where K is the sliding mode gain. The extended back EMF obtained according to equation (7) is a discontinuous high-frequency switching signal and cannot be directly substituted. To solve this problem, an external low-pass filter is usually required.

[0177] The sign function in the related scheme is used as a switching function, and the sign function is a discontinuous step function. When the system switches at high frequency, severe chattering phenomenon occurs, which greatly reduces the accuracy and stability of the motor control system. In the scheme of the application, in order to suppress the chattering problem of the sliding mode observer (SMO), the saturation function is used instead of the sign function in the related scheme. The saturation function avoids the sharp switching of the sign function through smooth transition, thereby significantly reducing the high-frequency jitter in the sliding mode control. In the scheme of the application, the saturation function is used instead of the sign function in the related scheme. The saturation function avoids the sharp switching of the sign function through smooth transition, thereby significantly reducing the high-frequency jitter in the sliding mode control.

[0178] In some embodiments, the control unit 104 obtains the rotor electric angular velocity estimation value of the motor and the rotor electric angular position estimation value of the motor based on the components of the back electromotive force estimation value of the motor in the alpha and beta axes, and after processing by a preset phase-locked loop module and a preset phased angle compensation module, including:

[0179] The control unit 104 is specifically further configured to obtain the rotor electric angular velocity estimation value of the motor and the initial value of the rotor electric angular position of the motor based on the components of the back electromotive force estimation value of the motor in the alpha and beta axes, and after processing by a preset phase-locked loop module. The initial value of the rotor electric angular position of the motor is the rotor electric angular position of the motor extracted by the phase-locked loop. The specific functions and processes of the control unit 104 are also referred to step S310.

[0180] The control unit 104 is specifically further configured to determine the rotor angle compensation bias value of the motor according to the rotor electric angular velocity estimation value of the motor. The rotor angle compensation bias value of the motor is the compensation bias The specific functions and processes of the control unit 104 are also referred to step S320.

[0181] The control unit 104 is specifically further configured to determine the rotor electric angular position estimation value of the motor according to the initial value of the rotor electric angular position of the motor and the rotor angle compensation bias value of the motor. Specifically, the product value of the initial value of the rotor electric angular position of the motor and the rotor angle compensation bias value of the motor is taken as the rotor electric angular position estimation value of the motor. The specific functions and processes of the control unit 104 are also referred to step S330.

[0182] Figure 7is a schematic diagram of the principle of the sliding mode observer. The sliding mode control is to use the voltage and current of the permanent magnet synchronous motor as the input, to get the estimated back electromotive force of the motor through the electromagnetic theory of the motor and the sliding mode algorithm, and to extract the motor rotor electric angle position and angular velocity from the estimated back electromotive force. The principle block diagram is shown in Figure 7 . As shown in Figure 7 , , , , are the stator voltage components of the motor, , are input into the sliding mode observer; , are the stator current components of the motor, respectively, , the difference between the first value output by the sliding mode observer and is input into the first input end of the saturation function sat() module, and the difference between the second value output by the sliding mode observer and is input into the second input end of the saturation function sat() module; , are the back electromotive force components of the motor, respectively, , the first output end of the saturation function sat() module outputs , and the second output end of the saturation function sat() module outputs ; the output by the first output end of the saturation function sat() module is input into the first input end of the low-pass filter, and the output by the first output end of the saturation function sat() module is also fed back to the first feedback end of the sliding mode observer; the output by the second output end of the saturation function sat() module is input into the second input end of the low-pass filter, and the output by the second output end of the saturation function sat() module is also fed back to the second feedback end of the sliding mode observer; , are the back electromotive force observation value components of the motor, respectively, , the first output end of the low-pass filter outputs , and the second output end of the low-pass filter outputs , the output by the first output end of the low-pass filter is input into the first input end of the phase-locked loop module based on feedforward compensation, and the output by the second output end of the low-pass filter is input into the second input end of the phase-locked loop module based on feedforward compensation; is the motor rotor electric angle position extracted by the phase-locked loop, The motor rotor angular velocity extracted by the phase-locked loop is outputted from a first output end of the phase-locked loop module based on feedforward compensation The motor rotor angular velocity extracted by the phase-locked loop is outputted from a first output end of the phase-locked loop module based on feedforward compensation ; The motor rotor angular velocity extracted by the phase-locked loop is outputted from a first output end of the phase-locked loop module based on feedforward compensation The motor rotor angular velocity extracted by the phase-locked loop is outputted from a first output end of the phase-locked loop module based on feedforward compensation The motor rotor angular velocity extracted by the phase-locked loop is outputted from a first output end of the phase-locked loop module based on feedforward compensation The motor rotor angular velocity extracted by the phase-locked loop is outputted from a first output end of the phase-locked loop module based on feedforward compensation The scheme of the application avoids the dramatic switching of the sign function, significantly reduces the high-frequency jitter in the sliding mode control, maintains the stability and tracking performance of the system in the presence of external disturbances, reduces the observation error of the sliding mode observer, improves the observation accuracy, and enhances the robustness of the system.

[0183] In some embodiments, the preset phase-locked loop module has a feedforward compensation link. The control unit 104 obtains the rotor electric angular velocity estimation value of the motor and the initial value of the rotor electric angle position of the motor by processing the components of the back electromotive force estimation value of the motor on the α and β axes using the preset phase-locked loop module, including:

[0184] The control unit 104 is specifically configured to determine the rotor position error signal of the motor based on the components of the back electromotive force estimation value of the motor on the α and β axes using the heterodyne method in the preset phase-locked loop module, wherein the rotor position error signal of the motor is the rotor position error signal obtained by the heterodyne method The specific functions and processes of the control unit 104 are also referred to step S410.

[0185] The control unit 104 is specifically configured to obtain the rotor position PI processing value of the motor by PI processing the rotor position error signal of the motor. The specific functions and processes of the control unit 104 are also referred to step S420.

[0186] The control unit 104 is specifically configured to obtain the feedforward compensation value as the rotor angle compensation value of the motor by processing the components of the back electromotive force estimation value of the motor on the α and β axes using the feedforward compensation link. The specific functions and processes of the control unit 104 are also referred to step S430.

[0187] The control unit 104 is specifically configured to take the sum of the rotor position PI processing value of the motor and the rotor angle compensation value of the motor as the rotor electric angular velocity estimation value of the motor;

[0188] The control unit 104 is further configured to integrate the estimated rotor electrical angular velocity of the motor to obtain the initial value of the rotor electrical angular position of the motor. The specific functions and processing of the control unit 104 are further described in step S440.

[0189] The feedforward compensation element is calculated using the following formula to obtain the feedforward compensation value:

[0190] =Feedforward compensation value;

[0191] in, , These are the components of the back electromotive force of the motor along the α and β axes, respectively. The permanent magnet flux linkage on the rotor of the motor.

[0192] Figure 9 This is a schematic diagram of a phase-locked loop (PLL) system based on feedforward compensation. Figure 9 As shown, , They are respectively , The components of the back electromotive force observation, - The value output after the first multiplier is the same as... The difference between the output values ​​after the second multiplier, multiplied by 1 / ( The motor rotor position error signal is obtained after the module. ; The PI-processed value is obtained after PI processing. , Through feedforward / The module processes the data to obtain the feedforward value. The sum of the PI processing value and the feedforward value is an estimate of the motor rotor's electrical angular velocity. . The estimated value of the electric angle position of the motor rotor is obtained after processing by the 1 / s module. . After being processed by the cos() module, the data is fed back to the first multiplier. After being processed by the sin() module, the result is fed back to the second multiplier. Figure 9 The present invention demonstrates improvements in using a phase-locked loop (PLL) structure to calculate motor rotor information, as well as improvements in adding a feedforward element to the PLL model. The feedforward-compensated PLL system effectively reduces chattering in sliding mode control, reduces observer error, and improves observation accuracy and system convergence speed.

[0193] To avoid errors introduced by the arctangent function and to ensure that the estimated electrical angle position of the motor rotor is close to the actual electrical angle position, thereby enabling rapid convergence of the phase-locked loop (PLL), a feedforward-based PLL system is used to extract information about the motor rotor's electrical angle position, such as the estimated value of the motor rotor's electrical angular velocity. Estimated value of the electrical angle position of the motor rotor ,like Figure 9 As shown. The motor rotor position error signal obtained by the heterodyne method. The angular velocity of the motor rotor can be estimated using a PI tracker. Then, by integration, the electrical angular position of the motor rotor can be obtained. .like Figure 9 As shown,

[0194] (8);

[0195] = (9).

[0196] From the above equation (8), we get Figure 10 The mathematical model of the feedforward phase-locked loop (PLL) system shown is as follows: Figure 10 This is a schematic diagram of the mathematical model of a feedforward phase-locked loop (PLL) system. Figure 10 As shown, The value processed by the s module, and and The difference via (k) p +k i The sum of the values ​​processed by the / s module is used as the motor rotor angular velocity. ; The 1 / s module processes the data to obtain the electrical angle position of the motor rotor. .Depend on Figure 10 We can obtain:

[0197] (10).

[0198] In the formula, The extracted electrical angle position of the motor rotor, The extracted angular velocity of the motor rotor, For the proportional gain of the PI controller, This is the integral gain of the PI controller. This is a reference value for estimating the rotor's electrical angle position. Let be the reference value for the estimated electric angular velocity of the rotor, and s be a complex variable in the Laplace transform.

[0199] Therefore, the closed-loop transfer function of the feedforward-based phase-locked loop (PLL) system is:

[0200] (11).

[0201] From equation (3), the output of the system fully replicates the changes of the input.

[0202] The arctangent function is needed in the calculation of the motor rotor speed and position by the sliding mode observer (SMO) in the related scheme, which has a large amount of calculation and can aggravate the chattering phenomenon of the system, affecting the measurement accuracy of the observer. Therefore, in the scheme of the present application, a phase-locked loop (PLL) structure is used to calculate the motor rotor information, avoiding a large amount of calculation and reducing the chattering phenomenon of the system.

[0203] The convergence speed of the saturation function in the calculation of the sliding mode observer (SMO) in the related scheme is slow, and the convergence speed of the observed current error is correspondingly reduced, resulting in a slow response speed of the system. Therefore, in the scheme of the present application, a feedforward link is added to the phase-locked loop model, so that the estimated electrical angle position of the motor rotor is close to the actual electrical angle position, the observation accuracy is improved, so that the phase-locked loop (PLL) system converges as soon as possible, the response speed is accelerated, and the tracking performance of the system is maintained.

[0204] In some embodiments, the control unit 104 determines the rotor angle compensation bias value of the motor according to the rotor electrical angular velocity estimation value of the motor, including:

[0205] The control unit 104 is specifically further configured to determine the electrical angular velocity interval to which the rotor electrical angular velocity estimation value of the motor belongs within the set electrical angular velocity range. The specific functions and processes of the control unit 104 are also referred to step S510.

[0206] The control unit 104 is specifically further configured to determine, according to the correspondence between the set electrical angular velocity interval and the set compensation bias value, the set compensation bias value corresponding to the set electrical angular velocity interval same as the electrical angular velocity interval to which the rotor electrical angular velocity estimation value of the motor belongs, as the compensation bias value corresponding to the electrical angular velocity interval to which the rotor electrical angular velocity estimation value of the motor belongs, as the rotor angle compensation bias value of the motor. The specific functions and processes of the control unit 104 are also referred to step S520.

[0207] After the phase-locked loop (PLL) system extracts the electrical angle position and angular velocity of the motor rotor, the delay effect caused by the low-pass filter must be eliminated. This can be achieved by adding a compensation bias to the uncompensated .

[0208] (12).

[0209] In the formula, This refers to the electrical angle position of the motor rotor. The electrical angle position of the motor rotor extracted by the phase-locked loop. To compensate for the offset, precise, staged angle compensation is performed for different speed ranges. This angle compensation must be precisely adjusted to suit other motor models. In this invention, the angle compensation is divided into nine angular velocity ranges. Each angular velocity range has its own slope of change, as detailed below. Figure 11 . Figure 11 To accurately determine the phased angle compensation formula, i.e., the correspondence between the speed range and angle compensation (Table 1), in... Figure 11 In Chinese, Omega is... Theta_offset is .

[0210] The sliding mode observer (SMO) in related solutions uses a low-pass filter (LPF) to filter high-frequency harmonics in the motor's back EMF, which introduces a delay problem in the motor control system. This delay is particularly pronounced in high-speed motor control systems, reducing system response speed and affecting the timeliness of the motor control system. Therefore, the solution in this invention employs precise, staged angle compensation to eliminate the delay effect in the sliding mode observer, accelerate the system response speed, and reduce the observer's observation error.

[0211] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0212] According to an embodiment of the present invention, a motor corresponding to a control device for a motor is also provided. This motor may include the control device for the motor described above.

[0213] Since the processing and functions implemented by the motor in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned device, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0214] According to an embodiment of the present invention, an air compressor corresponding to a control device for a motor is also provided. This air compressor may include: the control device for the motor described above, or the motor described above.

[0215] Since the processing and functions implemented by the air compressor in this embodiment are basically the same as those in the embodiments, principles and examples of the aforementioned device, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0216] According to an embodiment of the present application, a computer program product corresponding to the control method of the motor is also provided, comprising a computer program which, when executed by a processor, implements the steps of the control method of the motor described above.

[0217] Since the processing and functions realized by the product of the present embodiment are basically corresponding to the embodiments, principles and examples of the foregoing method, the descriptions of the present embodiment which are not elaborated can be referred to the relevant descriptions in the foregoing embodiments, which will not be repeated here.

[0218] According to an embodiment of the present application, a storage medium corresponding to the control method of the motor is also provided, comprising a stored program, wherein when the program is running, the device where the storage medium is located executes the steps of the control method of the motor described above.

[0219] Since the processing and functions realized by the storage medium of the present embodiment are basically corresponding to the embodiments, principles and examples of the foregoing method, the descriptions of the present embodiment which are not elaborated can be referred to the relevant descriptions in the foregoing embodiments, which will not be repeated here.

[0220] In summary, those skilled in the art can easily understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0221] The above only describes the embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method for controlling an electric motor, characterized in that, The motor has a stator and a rotor; the control method of the motor includes: While the motor is running, the stator voltage components of the motor in the α and β axes are obtained, and the stator current components of the motor in the α and β axes are also obtained. Based on the components of the stator voltage and stator current of the motor in the α and β axes, the back electromotive force of the motor in the α and β axes is estimated by processing the components of the stator voltage and stator current of the motor in the α and β axes using a preset sliding diaphragm observer module. Based on the back electromotive force estimate of the motor in the α and β axes, after processing by a preset phase-locked loop module and a preset staged angle compensation module, the estimated value of the motor's rotor electric angular velocity and the estimated value of the motor's rotor electric angular position are obtained. The motor is controlled based on the estimated rotor electrical angular velocity and the estimated rotor electrical angular position of the motor.

2. The motor control method according to claim 1, characterized in that, in, The switching function in the preset synovial observer module uses the saturation function sat(); And / or, The pre-defined phase-locked loop module includes a feedforward compensation stage; wherein, the feedforward compensation stage calculates a feedforward compensation value according to the following formula: =Feedforward compensation value; in, , These are the components of the back electromotive force of the motor along the α and β axes, respectively. The permanent magnet flux linkage on the rotor of the motor.

3. The motor control method according to claim 1, characterized in that, The preset slug observer module includes: a slug observer, a saturation function sat() processing module, and a filter with a preset filtering range; Based on the components of the stator voltage and stator current of the motor in the α and β axes, and after processing using a preset sliding film observer module, the estimated back electromotive force of the motor in the α and β axes is obtained, including: The components of the stator voltage of the motor on the α and β axes are processed by the sliding diaphragm observer to obtain the stator voltage sliding diaphragm processing value of the motor. The stator voltage sliding film processing value of the motor and the stator current of the motor in the α and β axes are processed by the saturation function sat() processing module to obtain the back electromotive force of the motor in the α and β axes. The components of the back electromotive force of the motor in the α and β axes are fed back to the sliding diaphragm observer; and the components of the back electromotive force of the motor in the α and β axes are processed by the filter of the preset filtering range to obtain the estimated value of the back electromotive force of the motor in the α and β axes.

4. The motor control method according to claim 1 or 3, characterized in that, Based on the back electromotive force estimate of the motor in the α and β axes, after processing using a preset phase-locked loop module and a preset staged angle compensation module, the estimated rotor electric angular velocity and the estimated rotor electric angular position of the motor are obtained, including: Based on the components of the back electromotive force estimate of the motor on the α and β axes, after processing by a preset phase-locked loop module, the estimated value of the rotor electric angular velocity of the motor and the initial value of the rotor electric angular position of the motor are obtained. Based on the estimated rotor electric angular velocity of the motor, determine the rotor angle compensation offset value of the motor; The product of the initial value of the rotor electrical angle position of the motor and the rotor angle compensation offset value of the motor is used as the estimated value of the rotor electrical angle position of the motor.

5. The motor control method according to claim 4, characterized in that, The pre-defined phase-locked loop module has a feedforward compensation stage; Based on the back electromotive force estimate of the motor in the α and β axes, after processing using a preset phase-locked loop module, the estimated rotor electric angular velocity and the initial value of the rotor electric angular position of the motor are obtained, including: In the preset phase-locked loop module, the rotor position error signal of the motor is determined by the heterodyne method based on the components of the back electromotive force estimate of the motor on the α and β axes. The rotor position error signal of the motor is processed by PI to obtain the PI processed value of the rotor position of the motor. Based on the components of the back electromotive force estimate of the motor in the α and β axes, the feedforward compensation circuit is used to process the data to obtain the feedforward compensation value, which is then used as the rotor angle compensation value of the motor. The sum of the PI processing value of the motor's rotor position and the compensation value of the motor's rotor angle is used as the estimated value of the motor's rotor electric angular velocity. The estimated rotor electrical angular velocity of the motor is integrated to obtain the initial value of the rotor electrical angular position of the motor. The feedforward compensation element is calculated using the following formula to obtain the feedforward compensation value: =Feedforward compensation value; in, , These are the components of the back electromotive force of the motor along the α and β axes, respectively. The permanent magnet flux linkage on the rotor of the motor.

6. The motor control method according to claim 4 or 5, characterized in that, Based on the estimated rotor electrical angular velocity of the motor, the rotor angle compensation offset value of the motor is determined, including: Within a set range of electrical angular velocities, determine the electrical angular velocity interval to which the estimated rotor electrical angular velocity of the motor belongs; Based on the correspondence between the set electrical angular velocity range and the set compensation bias value, the set compensation bias value corresponding to the set electrical angular velocity range to which the estimated rotor electrical angular velocity of the motor belongs is determined as the compensation bias value corresponding to the electrical angular velocity range to which the estimated rotor electrical angular velocity of the motor belongs, and is used as the set rotor angle compensation bias value of the motor.

7. A control device for an electric motor, characterized in that, The motor has a stator and a rotor; the control device for the motor includes: The acquisition unit is configured to acquire the stator voltage components of the motor in the α and β axes and the stator current components of the motor in the α and β axes when the motor is running. The control unit is configured to obtain the estimated back electromotive force of the motor in the α and β axes based on the components of the stator voltage and the stator current of the motor in the α and β axes, after processing by a preset sliding film observer module. The control unit is further configured to obtain the estimated rotor electric angular velocity and the estimated rotor electric angular position of the motor by processing the estimated back electromotive force of the motor in the α and β axes using a preset phase-locked loop module and a preset staged angle compensation module. The control unit is further configured to control the motor based on the estimated rotor electrical angular velocity and the estimated rotor electrical angular position of the motor.

8. An electric motor, characterized in that, include: The motor control device as described in claim 7.

9. An air compressor, characterized in that, include: The motor control device as described in claim 7, or the motor as described in claim 8.

10. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the motor control method according to any one of claims 1 to 6.

11. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the motor control method according to any one of claims 1 to 6.

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