Zero-speed and low-speed sensorless control method for synchronous reluctance motor based on parameter tuning

Abstract

The application discloses a zero-low-speed sensorless control method for a synchronous reluctance motor based on parameter setting, and belongs to the technical field of synchronous reluctance motor control. The application aims at solving the problem that the zero-low-speed sensorless control of the synchronous reluctance motor is affected by motor saturation and coupling characteristics, and position error influences the reliability of motor control. The application comprises the following steps: defining decoupling shaft system diqi and real shaft system drqr; determining decoupling angle and constructing a high-frequency model of the decoupling shaft system diqi voltage; performing parameter identification based on a high-frequency current response signal expression under an asynchronous rotating shaft system m-axis; determining an effective flux linkage vector expression and performing parameter setting based on the identification result; measuring a d-axis injected high-frequency sinusoidal voltage, calculating a high-frequency flux linkage component expression of the measuring shaft system dq by measuring a high-frequency voltage component expression of the shaft system dq, and then obtaining a high-frequency effective flux linkage vector expression of the measuring shaft system dq, and calculating a compensated electric angle θ er The application is used for the sensorless control of the synchronous reluctance motor.

Description

Technical Field

[0001] The invention relates to a zero-low-speed sensorless control method for a synchronous reluctance motor based on parameter setting, and belongs to the technical field of synchronous reluctance motor control. Background Art

[0002] Synchronous reluctance motors are essentially synchronous motors, offering a higher cost-performance ratio than permanent magnet synchronous motors and induction motors. Due to their unique rotor structure without permanent magnets, synchronous reluctance motors are inexpensive to manufacture and eliminate the risk of demagnetization. Therefore, they offer the advantages of low cost, ruggedness, reliability, and energy conservation. Research on zero- and low-speed sensorless control is crucial in industrial manufacturing and electrical transmission. Reducing the use of sensors can reduce industrial maintenance costs and improve control reliability. Therefore, research on zero- and low-speed sensorless control for synchronous reluctance motors in the industrial field can further reduce motor operating costs and improve motor control efficiency, which is of great significance for the widespread application of synchronous reluctance motors.

[0003] The synchronous reluctance motor model relies on the dq-axis inductances, which are affected by the motor's saturation and coupling characteristics. This prevents true decoupling of the inductance matrix, resulting in large position errors during traditional synchronous reluctance motor zero-speed and low-speed sensorless control, reducing the reliability of synchronous reluctance motor control. Analyzing changes in the inductance matrix can describe the motor's saturation and coupling characteristics, enabling parameter identification and calculation of the effective flux vector, thus mitigating the impact of inductance changes on synchronous reluctance motor zero-speed and low-speed sensorless control.

[0004] Based on this, it is of great significance to perform parameter identification in the zero-speed sensorless control of the synchronous reluctance motor to achieve parameter tuning for the precise control of the motor. Summary of the Invention

[0005] In order to solve the problem that the zero-speed and low-speed sensorless control of a synchronous reluctance motor is affected by motor saturation and coupling characteristics, resulting in position error that affects the reliability of motor control, the present invention provides a zero-speed and low-speed sensorless control method for a synchronous reluctance motor based on parameter setting.

[0006] A zero-speed sensorless control method for a synchronous reluctance motor based on parameter tuning of the present invention comprises:

[0007] The decoupled shaft system diqi is defined so that there is no mutual induction at the rotor position where the decoupled shaft system diqi is located. At the same time, the two-phase synchronous rotating shaft system of the synchronous reluctance motor is regarded as the real shaft system drqr. The angle between the decoupled shaft system diqi and the real shaft system drqr is defined as the decoupling angle δ. A high-frequency voltage model of the decoupled shaft system diqi and a high-frequency voltage model of the real shaft system drqr are constructed.

[0008] The asynchronous rotating shaft system m-axis is defined so that the asynchronous rotating shaft system m-axis rotates at a fixed speed relative to the di-axis. The high-frequency current response signal expression of the asynchronous rotating shaft system m-axis is obtained by combining the high-frequency voltage model of the decoupled shaft system diqi and the high-frequency voltage model of the real shaft system drqr. The decoupling angle δ and the di-axis inductance L are calculated based on the high-frequency current response signal expression. di and qi-axis inductance L qi identification;

[0009] Based on the decoupling angle δ and di-axis inductance L di and qi-axis inductance L qi Based on the identification result, the effective flux vector based on the decoupled shaft system diqi is set, and the expression of the effective flux vector with the same direction as the decoupled shaft system diqi is obtained through the parameter tuning link;

[0010] The measurement axis dq is defined based on the high-frequency model of the decoupled axis diqi voltage. The measurement axis dq is a dual-closed-loop controlled dq axis that eventually converges to the real axis drqr. A high-frequency sinusoidal voltage is injected into the measurement d-axis. Combining the relationship between voltage and flux, the high-frequency voltage component expression of the measurement axis dq is calculated to obtain the high-frequency flux component expression of the measurement axis dq.

[0011] Combined with the effective flux vector expression of the decoupled shaft system diqi, the high-frequency effective flux vector expression of the measured shaft system dq is obtained according to the high-frequency flux component expression of the measured shaft system dq. Then, the electrical angle of the decoupled shaft system diqi is calculated through the phase-locked loop. The decoupling angle δ obtained by identification is used to compensate the electrical angle of the decoupled shaft system diqi to obtain the compensated electrical angle θ of the real shaft system drqr. er , based on the compensated electrical angle θ er Perform zero-speed and low-speed sensorless control of synchronous reluctance motor.

[0012] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning of the present invention, the high-frequency voltage component expression of the decoupled shaft system diqi voltage high-frequency model is:

[0013]

[0014] Where u mh is the high-frequency sinusoidal voltage of the asynchronous rotating shaft system m axis; U h is the amplitude of the injected high-frequency sinusoidal voltage, ω h is the angular frequency of the injected high-frequency sinusoidal voltage; u dhi is the di-axis high-frequency voltage of the decoupled shaft system diqi, u qhi is the high-frequency voltage of the qi axis of the decoupled shaft system diqi, θ ei is the electrical angle of the decoupled axis diqi, θ em is the electrical angle of the m-axis of the asynchronous rotating shaft system.

[0015] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning of the present invention, the method for obtaining the high-frequency current response signal expression of the m-axis of the asynchronous rotating shaft system is:

[0016] The high-frequency model of the decoupled shaft system diqi voltage and the high-frequency model of the real shaft system drqr voltage under the condition of injecting high-frequency signal are:

[0017]

[0018] Where u dhi is the di-axis high-frequency voltage of the decoupled shaft system diqi, u qhi is the high frequency voltage of the qi axis of the decoupled shaft system diqi, [L i ] is the inductance matrix of the decoupled shaft system diqi, p is the differential operator, i dhi is the di-axis high-frequency current of the decoupled shaft system diqi, i qhi is the qi-axis high-frequency current of the decoupled shaft system diqi;

[0019] Where u dhr is the dr-axis high-frequency voltage of the real axis system drqr, u qhr is the high-frequency voltage of the qr axis of the real axis system drqr, [L r ] is the inductance matrix of the real axis system drqr; i dhr is the dr-axis high-frequency current of the real axis system drqr, i qhr is the qr-axis high-frequency current of the real axis system drqr;

[0020] Combining the high-frequency model of the decoupled shaft system diqi voltage in formula (1) and formula (2), the high-frequency current response signal expression of the asynchronous rotating shaft system m-axis is obtained:

[0021]

[0022] Where L xi To decouple the di-axis and qi-axis inductances of the axis system diqi, i mh is the high-frequency current of the m-axis of the rotating axis system.

[0023] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter setting of the present invention, the decoupling angle δ and the di-axis inductance L are di and qi-axis inductance L qi The identification method is:

[0024] The high-frequency current i on the rotating axis m mhThe high-frequency current response signal is processed to obtain an envelope curve; the sine curve of the envelope curve is determined by the di-axis position, and then a sine curve consistent with the sinusoidal change of the envelope curve is fitted according to the true position of the dr-axis. The phase difference of the sine curve is solved by discrete Fourier transform to obtain the phase difference between the di-axis position and the true position of the dr-axis as the decoupling angle δ; at the same time, the inductance curve of the rotating axis system m-axis is calculated according to the envelope curve, and the maximum value of the inductance curve is the di-axis inductance L di , the minimum value is the qi-axis inductance L qi ; Specifically:

[0025] The decoupling angle δ and di-axis inductance L are calculated using the following formula (4): di and qi-axis inductance L qi :

[0026]

[0027] Where I mh is the high-frequency current amplitude of the rotating axis m, ∠ is the sign of the vector phase angle, θ erm The real electrical angle of the real axis drqr obtained by the mechanical position sensor, L m is the m-axis inductance of the rotating axis system.

[0028] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning of the present invention, the effective flux vector ψ of the decoupled shaft system diqi is a for:

[0029]

[0030] Where ψ s is the stator flux vector, i s is the stator current vector, i di is the di-axis current of the decoupled shaft system diqi.

[0031] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning of the present invention, the expression of the high-frequency voltage component of the measured shaft system dq is:

[0032]

[0033] In the formula To measure the d-axis high-frequency voltage of the axis system dq, t is the time, Δθ is the q-axis high-frequency voltage of the measured axis system dq; e To measure the position difference between the axis system dq and the decoupling axis system diqi, In the formula is the electrical angle of the measured axis system dq; To measure the d-axis high-frequency current of the axis system dq, To measure the q-axis high-frequency current of the shaft system dq.

[0034] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning of the present invention, the expression for measuring the dq high-frequency flux component of the shaft system is:

[0035]

[0036] In the formula To measure the d-axis high-frequency magnetic flux of the shaft system dq, It is used to measure the q-axis high-frequency magnetic flux of the shaft system dq.

[0037] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning of the present invention, the high-frequency effective flux vector expression of the measured shaft system dq is:

[0038]

[0039] To measure the d-axis high-frequency effective magnetic flux vector of the shaft system dq, It is the q-axis high-frequency effective magnetic flux vector of the measured shaft system dq.

[0040] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning of the present invention, the method for calculating the decoupling position of the di-axis of the decoupling shaft system diqi through the phase-locked loop is:

[0041] According to formula (8), we can get:

[0042]

[0043] Then the synchronous reluctance motor rotor speed ω is calculated through the phase-locked loop e and the electrical angle θ of the decoupled shaft system diqi ei :

[0044]

[0045] In the formula For the PI calculation link, K p is the proportional adjustment coefficient, K i is the integral adjustment coefficient, s is the integral operator;

[0046] The decoupling angle δ is used to decouple the electrical angle θ of the decoupled shaft system diqi ei Compensation is performed to obtain the compensated electrical angle θ of the real axis system drqr er .

[0047] According to the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning of the present invention, the observed position error of the zero-speed sensorless control of the synchronous reluctance motor is eliminated by parameter tuning to compensate the back electrical angle θ er Based on this, zero-speed and low-speed position sensorless control of synchronous reluctance motor is realized.

[0048] Beneficial effects of the present invention: The present invention obtains identification parameters in parameter tuning through parameter identification, uses the parameter tuning link to calculate the effective flux vector, avoids the influence of inductance changes on the zero- and low-speed sensorless control of the synchronous reluctance motor, and proposes decoupled shaft system high-frequency effective flux observation from the perspective of inductance matrix decoupling, which is used for zero- and low-speed sensorless control of the synchronous reluctance motor considering motor saturation and coupling characteristics, and can improve the motor control accuracy.

[0049] The method of the present invention is based on the motor model characteristics of the defined decoupled shaft system diqi to perform zero-speed position sensorless control of the synchronous reluctance motor, based on the real-time acquisition of the decoupling angle δ and inductance L under different working conditions of the motor. di 、L qi The identification value of the decoupled shaft voltage high-frequency model is combined with the parameter tuning link to eliminate the observed position error of the synchronous reluctance motor zero-speed and low-speed position sensorless control, thereby realizing the precise control of the synchronous reluctance motor zero-speed and low-speed position sensorless.

[0050] The method of the present invention takes into account the coupling terms existing in the inductance matrix of the synchronous reluctance motor under motor saturation and coupling characteristics, and proposes a decoupling shaft system and a decoupling angle definition to assist motor parameter identification and zero-speed and low-speed position sensorless control.

[0051] The method of the present invention uses the asynchronous rotating shaft system m-axis high-frequency injection strategy to realize the identification of the decoupling angle and inductance of the decoupled shaft system diqi, and applies the parameter setting method to improve the accuracy of zero-low-speed position sensorless control of the synchronous reluctance motor.

[0052] The method of the present invention designs a decoupled shaft system high-frequency effective flux observation based on parameter tuning. In the parameter tuning link, the motor parameters in the decoupled shaft system high-frequency effective flux observation are set as real-time identification results, and the output position information is directly compensated by the decoupling angle, ultimately achieving zero-low-speed sensorless precise control of the synchronous reluctance motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the positional relationship among the decoupled shaft system diqi, the real shaft system drqr and the αβ shaft system in the zero-speed sensorless control method of the synchronous reluctance motor based on parameter tuning according to the present invention; dr is the dr axis inductance, L qr is the qr axis inductance, L dqr and L qdris the mutual inductance of the real drqr axis system;

[0054] Figure 2 ω is a vector diagram of the parameter setting process of the decoupling shaft system diqi of the synchronous reluctance motor in the method of the present invention; m is the angular velocity of the asynchronous rotating axis system m-axis;

[0055] Figure 3 Schematic diagram of the effective flux vector of the decoupled shaft system diqi of the synchronous reluctance motor in the method of the present invention; Axis represents the d-axis of the measuring axis system dq;

[0056] Figure 4 This is a flow chart of the zero-speed sensorless control method of the synchronous reluctance motor based on parameter setting according to the present invention; e_ref is the given value of the angular velocity of the synchronous reluctance motor, i d 、i q is the dq current of the two-phase synchronous rotating shaft system, i dref is the given current of the d-axis of the two-phase synchronous rotating shaft system, i qref is the given current of the q axis of the two-phase synchronous rotating shaft system, u α is the α-axis voltage, u β is the β-axis voltage, i α is the α-axis current, i β is the β-axis current, To measure the d-axis voltage of the axis system dq, To measure the q-axis voltage of the axis system dq, The high-frequency voltage sinusoidal signal injected into the d-axis of the measuring axis dq, i αh is the α-axis high-frequency current, i βh is the β-axis high-frequency current;

[0057] Figure 5 This is an experimental waveform diagram of parameter setting using the method of the present invention; mh is the high frequency voltage of the rotating axis m, in the figure f r is the reference signal for reconstructing the position output by the mechanical position sensor, which is equal to -cos(2(θ er -θ em ));

[0058] Figure 6 The zero-speed control experiment results of the synchronous reluctance motor zero-speed sensorless control using the method of the present invention are shown in FIG. e_real The electrical angle waveform output by the mechanical position sensor is the real electrical angle θ of the real axis drqr obtained by the mechanical position sensor. erm ,θ e_est The sensorless control output electrical angle output by the method of the present invention, that is, the compensated electrical angle θ er, θ e_err for θ e_real with θ e_est Position error; i a is a-phase current;

[0059] Figure 7 Fig. 4 is a low-speed control experimental result diagram of the synchronous reluctance motor zero-low-speed sensorless control method. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0061] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0062] The present application will be further described below with reference to the drawings and specific embodiments, but is not limited to the present application.

[0063] Specific embodiment one, in combination Figures 1 to 4 with the drawings, the present application provides a synchronous reluctance motor zero-low-speed sensorless control method based on parameter setting, comprising:

[0064] Define the decoupling shaft system diqi, so that there is no mutual inductance at the rotor position where the decoupling shaft system diqi is located; at the same time, the two-phase synchronous rotating shaft system of the synchronous reluctance motor is taken as the real shaft system drqr; the angle between the decoupling shaft system diqi and the real shaft system drqr is defined as the decoupling angle δ; the high-frequency voltage model of the decoupling shaft system diqi and the high-frequency voltage model of the real shaft system drqr are constructed; both of them describe the motor model after considering the motor saturation and coupling characteristics, and the decoupling angle in the decoupling shaft system diqi can describe the mutual inductance in the high-frequency voltage model of the real shaft system drqr;

[0065] Define the asynchronous rotating shaft system m-axis, so that the asynchronous rotating shaft system m-axis rotates at a fixed speed relative to the di-axis; obtain the high-frequency current response signal expression of the asynchronous rotating shaft system m-axis in combination with the high-frequency voltage model of the decoupling shaft system diqi and the high-frequency voltage model of the real shaft system drqr; and identify the decoupling angle δ, the di-axis inductance L di and the qi-axis inductance L qi based on the high-frequency current response signal expression;

[0066] Again, based on the decoupling angle δ, the di-axis inductance L di and the qi-axis inductance L qiBased on the identification result of , the effective flux vector based on the decoupled shaft system diqi is set, and the parameter tuning link is added to obtain the expression of the effective flux vector with the same direction as the decoupled shaft system diqi; the effective flux vector is calculated using the identification value to eliminate the observation position error;

[0067] The measurement axis dq is defined based on the high-frequency model of the decoupled axis diqi voltage. The measurement axis dq is a dual-closed-loop controlled dq axis system. Ideally, it is controlled without a position sensor and ultimately converges to the real axis drqr. A high-frequency sinusoidal voltage is injected into the measurement d-axis. Combining the relationship between voltage and flux, the high-frequency voltage component expression of the measurement axis dq is calculated to obtain the high-frequency flux component expression of the measurement axis dq.

[0068] Combined with the effective flux vector expression of the decoupled shaft system diqi, the high-frequency effective flux vector expression of the measured shaft system dq is obtained according to the high-frequency flux component expression of the measured shaft system dq. Then, the electrical angle of the decoupled shaft system diqi is calculated through the phase-locked loop. The decoupling angle δ obtained by identification is used to compensate the electrical angle of the decoupled shaft system diqi to obtain the compensated electrical angle θ of the real shaft system drqr. er , based on the compensated electrical angle θ er Perform zero-speed and low-speed sensorless control of synchronous reluctance motor.

[0069] In this embodiment, a high-frequency voltage model of the dq axis system and a high-frequency voltage model of the real axis system drqr are obtained when a high-frequency signal is injected. Considering the motor saturation and coupling characteristics, the mutual inductance in the real axis system drqr inductance matrix is ​​not zero, and the self-inductance will change with the change of operating conditions. At this time, the motor inductance matrix contains coupling terms, which is not conducive to the design of the flux observer, and the change in inductance will cause position errors in the sensorless control of the motor. The decoupled axis system diqi voltage high-frequency model and the real axis system drqr voltage high-frequency model both describe the motor model after considering the motor saturation and coupling characteristics. However, the inductance matrix in the decoupled axis system diqi voltage high-frequency model is in a decoupled form. The decoupling angle can be used to represent the mutual inductance variable, simplifying the motor model. The parameter setting link and sensorless control link are designed based on the decoupled axis system diqi voltage high-frequency model.

[0070] Combine Figure 1 As shown in the figure, since the motor models of the decoupled shaft system diqi and the real shaft system drqr are consistent, both are motor models after considering the motor saturation and coupling characteristics, the inductance coefficient relationship expression of the two dq shaft systems can be established at this time.

[0071] The position information of the asynchronous rotating shaft system and the decoupled shaft system is as follows Figure 2As shown in the figure, the high-frequency sinusoidal voltage is injected into the asynchronous rotating shaft system m-axis and combined with the high-frequency model of the decoupled shaft system diqi voltage to obtain the high-frequency current response signal expression. Based on the high-frequency current response signal expression of the asynchronous rotating shaft system m-axis, the decoupling angle δ and inductance L of the decoupled shaft system diqi are realized. di , L qi identification, providing real-time identification value for parameter setting.

[0072] The effective flux vector is designed based on the decoupled shaft system diqi. Through the parameter setting link, the effective flux vector expression with the same direction as the di axis is obtained, as shown in the following example: Figure 3 shown.

[0073] This implementation achieves zero-speed, low-speed sensorless control of a synchronous reluctance motor, taking into account motor saturation and coupling characteristics. Based on the changes in the inductance matrix under motor saturation and coupling characteristics, a decoupled shaft system and decoupling angle definition are proposed to establish a decoupled shaft system motor decoupling model. Based on this model, a parameter tuning method and a high-frequency effective flux observer are designed. This parameter tuning eliminates the observed position error during zero-speed, low-speed, sensorless position control of the synchronous reluctance motor.

[0074] Combine Figure 1 As shown, considering the motor saturation and coupling characteristics, according to the definition of the decoupling axis diqi and the real axis drqr, the decoupling angle δ is:

[0075] δ=θ er -θ ei .

[0076] Since the motor states represented by the two dq axis systems are the same, the relationship between the two dq axis systems can be established based on coordinate transformation. The inductance relationship expression of the two dq axis systems is:

[0077]

[0078] Where [L i ] is the decoupled shaft system diqi inductance matrix, which is L di is the di-axis inductance, L qi is the qi-axis inductance, and the mutual inductance is 0; [L r ] is the inductance matrix of the real axis system drqr, specifically L dr is the dr axis inductance, L qr is the qr axis inductance, L dqr and L qdr is the mutual inductance of the real axis system drqr; is the coordinate transformation matrix between the real axis system drqr and the decoupled axis system diqi.

[0079] Considering motor saturation and coupling characteristics, the mutual inductance in the real-axis drqr inductance matrix is ​​not zero, and the self-inductance varies with operating conditions. This motor inductance matrix contains coupling terms, which hinders the design of the flux observer. Furthermore, changes in inductance can introduce position errors during sensorless motor control. Both the decoupled-axis diqi voltage high-frequency model and the real-axis drqr voltage high-frequency model describe the motor model after accounting for motor saturation and coupling characteristics. However, the decoupled-axis diqi inductance matrix is ​​decoupled, allowing the mutual inductance variables to be represented using the decoupling angle, simplifying the motor model. The parameter tuning and sensorless control stages are designed based on the decoupled-axis diqi voltage high-frequency model.

[0080] Furthermore, after constructing the high-frequency model of the decoupled shaft system diqi voltage, the positional relationship between the asynchronous rotating shaft system m-axis and the decoupled shaft system diqi is as follows: Figure 2 As shown in the figure, a high-frequency sinusoidal voltage is injected into the asynchronous rotating shaft system m-axis, and the high-frequency voltage component expression of the high-frequency model of the decoupled shaft system diqi voltage is:

[0081]

[0082] Where u mh is the high-frequency sinusoidal voltage of the asynchronous rotating shaft system m axis; U h is the amplitude of the injected high-frequency sinusoidal voltage, ω h is the angular frequency of the injected high-frequency sinusoidal voltage; u dhi is the di-axis high-frequency voltage of the decoupled shaft system diqi, u qhi is the high-frequency voltage of the qi axis of the decoupled shaft system diqi, θ ei is the electrical angle of the decoupled shaft system diqi, θ em is the electrical angle of the m-axis of the asynchronous rotating shaft system.

[0083] Combine Figure 2 As shown in Figure 2, the method for obtaining the high-frequency current response signal expression of the asynchronous rotating shaft system m-axis is:

[0084] The high-frequency model of the decoupled shaft system diqi voltage and the high-frequency model of the real shaft system drqr voltage under the condition of injecting high-frequency signal are:

[0085]

[0086] Where u dhi is the di-axis high-frequency voltage of the decoupled shaft system diqi, u qhi is the high frequency voltage of the qi axis of the decoupled shaft system diqi, [L i ] is the inductance matrix of the decoupled shaft system diqi, p is the differential operator, i dhi is the di-axis high-frequency current of the decoupled shaft system diqi, i qhi is the qi-axis high-frequency current of the decoupled shaft system diqi;

[0087] Where u dhr is the dr-axis high-frequency voltage of the real axis system drqr, u qhr is the high-frequency voltage of the qr axis of the real axis system drqr, [L r ] is the inductance matrix of the real axis system drqr, specifically L dr is the dr axis inductance, L qr is the qr axis inductance, L dqr and L qdr is the mutual inductance of the real axis system drqr; i dhr is the dr-axis high-frequency current of the real axis system drqr, i qhr is the qr-axis high-frequency current of the real axis system drqr;

[0088] The parameter tuning link and sensorless control link are designed based on the high-frequency model of the decoupled shaft system diqi voltage. The high-frequency model of the decoupled shaft system diqi voltage in formula (1) and formula (2) is further combined to obtain the high-frequency current response signal expression of the asynchronous rotating shaft system m-axis:

[0089]

[0090] Where L xi To decouple the di-axis and qi-axis inductances of the axis system diqi, i mh is the high-frequency current of the m-axis of the rotating axis system.

[0091] Decoupling angle δ, di-axis inductance L di and qi-axis inductance L qi The identification method is:

[0092] In order to realize the decoupling angle δ and inductance L of the decoupling shaft system diqi based on the high-frequency model of the decoupling shaft system diqi voltage di , L qi Identification of the high-frequency current i of the rotating axis m mh The high-frequency current response signal is processed to obtain an envelope curve; the sine curve of the envelope curve is determined by the di-axis position, and then a sine curve consistent with the sinusoidal change of the envelope curve is fitted according to the true position of the dr-axis. The phase difference of the sine curve is solved by discrete Fourier transform to obtain the phase difference between the di-axis position and the true position of the dr-axis as the decoupling angle δ; at the same time, the inductance curve of the rotating axis system m-axis is calculated according to the envelope curve, and the maximum value of the inductance curve is the di-axis inductance L di , the minimum value is the qi-axis inductance L qi Specifically:

[0093] The decoupling angle δ and di-axis inductance L are calculated using the following formula (4): diand qi-axis inductance L qi :

[0094]

[0095] where I mh is the high-frequency current amplitude of the m-axis of the rotating shaft system, ∠ is the vector phase angle symbol, θ erm is the real shaft system drqr real electrical angle obtained by the mechanical position sensor, L m is the m-axis inductance of the rotating shaft system.

[0096] Figure 5 is the experimental waveform diagram in the parameter setting process, which is the high-frequency current of the asynchronous rotating shaft system in formula (3), the high-frequency voltage of the asynchronous rotating shaft system in formula (1), and the decoupling angle position identification diagram and inductance curve waveform diagram obtained by formula (4). The real-time identification value can assist the parameter setting link and eliminate the observation position error of the synchronous reluctance motor zero-speed position sensorless control.

[0097] Further, in combination with Figure 3 , the effective flux linkage vector is designed based on the decoupled shaft system diqi, the real-time identification value is substituted in the effective flux linkage vector calculation process, and the effective flux linkage vector ψ a of the decoupled shaft system diqi is:

[0098]

[0099] where ψ s is the stator flux linkage vector, i s is the stator current vector, i di is the di-axis current of the decoupled shaft system diqi.

[0100] Further, a high-frequency sinusoidal voltage is injected to the d-axis of the measurement shaft system dq, and the high-frequency voltage component expression of the measurement shaft system dq is:

[0101]

[0102] where is the d-axis high-frequency voltage of the measurement shaft system dq, t is time, is the q-axis high-frequency voltage of the measurement shaft system dq; Δθ e is the position difference between the measurement shaft system dq and the decoupled shaft system diqi, and is where is the electrical angle of the measurement shaft system dq; is the d-axis high-frequency current of the measurement shaft system dq, is the q-axis high-frequency current of the measurement shaft system dq.

[0103] In this embodiment, since the flux is the voltage integration result, the expression for the measured shaft system dq high-frequency flux component is:

[0104]

[0105] In the formula To measure the d-axis high-frequency magnetic flux of the shaft system dq, It is used to measure the q-axis high-frequency magnetic flux of the shaft system dq.

[0106] The high-frequency effective flux vector expression of the measured shaft system dq is:

[0107]

[0108] To measure the d-axis high-frequency effective magnetic flux vector of the shaft system dq, It is the q-axis high-frequency effective magnetic flux vector of the measured shaft system dq.

[0109] Going further, combined Figure 4 As shown in FIG, the method for calculating the decoupling position of the decoupling shaft system diqi by the phase-locked loop is as follows: the ratio of the dq-axis high-frequency effective flux components of the measuring shaft system dq is the tangent value of the position difference between the measuring shaft system dq and the decoupling shaft system diqi, which is obtained according to formula (8):

[0110]

[0111] Then the synchronous reluctance motor rotor speed ω is calculated through the phase-locked loop e and the electrical angle θ of the decoupled shaft system diqi ei :

[0112]

[0113] In the formula For the PI calculation link, K p is the proportional adjustment coefficient, K i is the integral adjustment coefficient, s is the integral operator;

[0114] The decoupling angle δ is used to decouple the electrical angle θ of the decoupled shaft system diqi ei Compensation is performed to obtain the compensated electrical angle θ of the real axis system drqr er .

[0115] Finally, the observed position error of the synchronous reluctance motor zero low speed position sensorless control is eliminated by parameter tuning to compensate the back electrical angle θ er Based on this, zero-speed and low-speed position sensorless control of synchronous reluctance motor is realized.

[0116] Figure 6 and Figure 7This figure shows the experimental results of sensorless control of the synchronous reluctance motor at zero speed and low speed after substituting the identification results of parameter tuning on the synchronous reluctance motor drag test platform. It can be seen that when parameter tuning and decoupling angle compensation measures are adopted, the observed position error of the dq axis system is within the allowable error range, verifying the effectiveness of the zero and low speed sensorless control of the synchronous reluctance motor based on parameter tuning.

[0117] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in conjunction with other described embodiments.

Claims

1. A zero-speed sensorless control method for a synchronous reluctance motor based on parameter tuning, characterized in that: include: The decoupled shaft system diqi is defined so that there is no mutual induction at the rotor position where the decoupled shaft system diqi is located. At the same time, the two-phase synchronous rotating shaft system of the synchronous reluctance motor is regarded as the real shaft system drqr. The angle between the decoupled shaft system diqi and the real shaft system drqr is defined as the decoupling angle δ. A high-frequency voltage model of the decoupled shaft system diqi and a high-frequency voltage model of the real shaft system drqr are constructed. The asynchronous rotating shaft system m-axis is defined so that the asynchronous rotating shaft system m-axis rotates at a fixed speed relative to the di-axis. The high-frequency current response signal expression of the asynchronous rotating shaft system m-axis is obtained by combining the high-frequency voltage model of the decoupled shaft system diqi and the high-frequency voltage model of the real shaft system drqr. The decoupling angle δ and the di-axis inductance L are calculated based on the high-frequency current response signal expression. di and qi-axis inductance L qi identification; Based on the decoupling angle δ and di-axis inductance L di and qi-axis inductance L qi Based on the identification result, the effective flux vector based on the decoupled shaft system diqi is set, and the expression of the effective flux vector with the same direction as the decoupled shaft system diqi is obtained through the parameter tuning link; The measurement axis dq is defined based on the high-frequency model of the decoupled axis diqi voltage. The measurement axis dq is a dual-closed-loop controlled dq axis that eventually converges to the real axis drqr. A high-frequency sinusoidal voltage is injected into the measurement d-axis. Combining the relationship between voltage and flux, the high-frequency voltage component expression of the measurement axis dq is calculated to obtain the high-frequency flux component expression of the measurement axis dq. Combined with the effective flux vector expression of the decoupled shaft system diqi, the high-frequency effective flux vector expression of the measured shaft system dq is obtained according to the high-frequency flux component expression of the measured shaft system dq. Then, the electrical angle of the decoupled shaft system diqi is calculated through the phase-locked loop. The decoupling angle δ obtained by identification is used to compensate the electrical angle of the decoupled shaft system diqi to obtain the compensated electrical angle θ of the real shaft system drqr. er , based on the compensated electrical angle θ er Perform zero-speed and low-speed sensorless control of synchronous reluctance motor; The high-frequency voltage component expression of the decoupled shaft system diqi voltage high-frequency model is: Where u mh is the high-frequency sinusoidal voltage of the asynchronous rotating shaft system m axis; U h is the amplitude of the injected high-frequency sinusoidal voltage, ω h is the angular frequency of the injected high-frequency sinusoidal voltage; u dhi is the di-axis high-frequency voltage of the decoupled shaft system diqi, u qhi is the high-frequency voltage of the qi axis of the decoupled shaft system diqi, θ ei is the electrical angle of the decoupled shaft system diqi, θ em is the electrical angle of the asynchronous rotating shaft system m-axis; The method to obtain the high-frequency current response signal expression of the asynchronous rotating shaft system m-axis is: The high-frequency model of the decoupled shaft system diqi voltage and the high-frequency model of the real shaft system drqr voltage under the condition of injecting high-frequency signal are: Where u dhi is the di-axis high-frequency voltage of the decoupled shaft system diqi, u qhi is the high frequency voltage of the qi axis of the decoupled shaft system diqi, [L i ] is the inductance matrix of the decoupled shaft system diqi, p is the differential operator, i dhi is the di-axis high-frequency current of the decoupled shaft system diqi, i qhi is the qi-axis high-frequency current of the decoupled shaft system diqi; Where u dhr is the dr-axis high-frequency voltage of the real axis system drqr, u qhr is the high-frequency voltage of the qr axis of the real axis system drqr, [L r ] is the inductance matrix of the real axis system drqr; i dhr is the dr-axis high-frequency current of the real axis system drqr, i qhr is the qr-axis high-frequency current of the real axis system drqr; Combining the high-frequency model of the decoupled shaft system diqi voltage in formula (1) and formula (2), the high-frequency current response signal expression of the asynchronous rotating shaft system m-axis is obtained: Where L xi To decouple the di-axis and qi-axis inductances of the axis system diqi, i mh is the high-frequency current of the m-axis of the rotating axis system; Decoupling angle δ, di-axis inductance L di and qi-axis inductance L qi The identification method is: The high-frequency current i on the rotating axis m mh The high-frequency current response signal is processed to obtain an envelope curve; the sine curve of the envelope curve is determined by the di-axis position, and then a sine curve consistent with the sinusoidal change of the envelope curve is fitted according to the true position of the dr-axis. The phase difference of the sine curve is solved by discrete Fourier transform to obtain the phase difference between the di-axis position and the true position of the dr-axis as the decoupling angle δ; at the same time, the inductance curve of the rotating axis system m-axis is calculated according to the envelope curve, and the maximum value of the inductance curve is the di-axis inductance L di , the minimum value is the qi-axis inductance L qi ; Specifically: The decoupling angle δ and di-axis inductance L are calculated using the following formula (4): di and qi-axis inductance L qi : Where I mh is the high-frequency current amplitude of the rotating axis m, ∠ is the sign of the vector phase angle, θ erm The real electrical angle of the real axis drqr obtained by the mechanical position sensor, L m is the inductance of the m-axis of the rotating axis system.

2. The zero-speed sensorless control method for a synchronous reluctance motor based on parameter tuning according to claim 1 is characterized in that: The effective flux vector ψ based on the decoupled shaft system diqi a for: Where ψ s is the stator flux vector, i s is the stator current vector, i di is the di-axis current of the decoupled shaft system diqi.

3. The zero-speed sensorless control method for a synchronous reluctance motor based on parameter tuning according to claim 2, characterized in that: The expression of the high-frequency voltage component of the measuring shaft system dq is: In the formula To measure the d-axis high-frequency voltage of the axis system dq, t is the time, Δθ is the q-axis high-frequency voltage of the measured axis system dq; e To measure the position difference between the axis system dq and the decoupling axis system diqi, In the formula is the electrical angle of the measured axis system dq; To measure the d-axis high-frequency current of the axis system dq, To measure the q-axis high-frequency current of the shaft system dq.

4. The zero-speed sensorless control method for a synchronous reluctance motor based on parameter tuning according to claim 3 is characterized in that: The expression for measuring the dq high-frequency magnetic flux component of the shaft system is: In the formula To measure the d-axis high-frequency magnetic flux of the shaft system dq, It is used to measure the q-axis high-frequency magnetic flux of the shaft system dq.

5. The zero-speed sensorless control method for a synchronous reluctance motor based on parameter tuning according to claim 4 is characterized in that: The high-frequency effective flux vector expression of the measured shaft system dq is: To measure the d-axis high-frequency effective magnetic flux vector of the shaft system dq, It is the q-axis high-frequency effective magnetic flux vector of the measured shaft system dq.

6. The zero-speed sensorless control method for a synchronous reluctance motor based on parameter tuning according to claim 5, characterized in that: The method for calculating the decoupling position of the di-axis of the decoupling shaft system diqi through the phase-locked loop is: According to formula (8), we can get: Then the synchronous reluctance motor rotor speed ω is calculated through the phase-locked loop e and the electrical angle θ of the decoupled shaft system diqi ei : In the formula For the PI calculation link, K p is the proportional adjustment coefficient, K i is the integral adjustment coefficient, s is the integral operator; The decoupling angle δ is used to decouple the electrical angle θ of the decoupled shaft system diqi ei Compensation is performed to obtain the compensated electrical angle θ of the real axis system drqr er .

7. The zero-speed sensorless control method for a synchronous reluctance motor based on parameter tuning according to claim 6, characterized in that: Eliminate the observed position error of the synchronous reluctance motor zero-speed position sensorless control by parameter tuning to compensate for the back-electrical angle θ er Based on this, zero-speed and low-speed position sensorless control of synchronous reluctance motor is realized.

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