Permanent magnet synchronous motor current control method based on incremental dpcc controller

Abstract

The application belongs to the technical field of motor control, and particularly relates to a permanent magnet synchronous motor current control method based on an incremental DPCC controller. The method comprises the following steps: S1, constructing an incremental extended state observer; S2, constructing an incremental DPCC controller based on the incremental extended state observer; S3, performing inductance parameter self-correction based on a fixed time gradient descent method to obtain identification of the inductance parameter; and S4, feeding back the identification result of the inductance parameter to the incremental extended state observer and the incremental DPCC controller, performing online identification and real-time updating on the inductance parameter, and realizing robust current control on the permanent magnet synchronous motor. The application can eliminate the need of the control system for resistance and flux linkage, and improve the robustness of the control system to the inductance parameter through inductance parameter identification.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of motor control, and particularly relates to a permanent magnet synchronous motor current control method based on an incremental DPCC controller. BACKGROUND

[0002] The permanent magnet synchronous motor is widely used in many fields such as ground-based large-aperture telescopes and new energy vehicles due to its advantages of high efficiency, high power density and easy maintenance. However, as the control demand improves, in order to realize high-precision and fast-response current control, the traditional control method cannot meet the requirements. The deadbeat current predictive controller (DPCC) is outstanding due to its excellent dynamic response performance and accurate current tracking ability. However, the DPCC control strategy is very sensitive to system parameter changes. The motor parameters (such as resistance, inductance and flux linkage) will change due to factors such as temperature and magnetic saturation in actual operation, which will cause the system control performance to decrease, the current tracking accuracy to deteriorate, and even may cause the system to be unstable. SUMMARY

[0003] Therefore, the application aims to provide a permanent magnet synchronous motor current control method based on an incremental DPCC controller to solve the problem that the existing DPCC control strategy is very sensitive to system parameter changes. The motor parameters (such as resistance, inductance and flux linkage) will change due to factors such as temperature and magnetic saturation in actual operation, which will cause the system control performance to decrease, the current tracking accuracy to deteriorate, and even may cause the system to be unstable. The application improves the structure of the traditional DPCC and the traditional extended state observer (ESO), proposes an improved DPCC based on incremental ESO and an inductance identification algorithm based on the error between the actual current and the predicted current, which can eliminate the need for resistance and flux linkage in the control system, and improve the robustness of the control system to inductance parameters through inductance parameter identification.

[0004] To achieve the above purpose, the technical scheme of the application is as follows:

[0005] A permanent magnet synchronous motor current control method based on an incremental DPCC controller, specifically comprising the following steps:

[0006] S1: Constructing an incremental extended state observer, the incremental extended state observer is used to estimate the lumped disturbance of the permanent magnet synchronous motor and output the predicted current of the permanent magnet synchronous motor;

[0007] S2: Constructing an incremental DPCC controller based on the lumped disturbance estimation result and the predicted current output by the incremental extended state observer;

[0008] S3: using the fixed time gradient descent method to correct the inductance parameter of the difference between the predicted current output by the incremental extended state observer and the actual current of the permanent magnet synchronous motor, and obtaining the identification of the inductance parameter;

[0009] S4: feeding back the identification result of the inductance parameter to the incremental extended state observer and the incremental DPCC controller, and performing online identification and real-time updating of the inductance parameter, so as to realize the robust current control of the permanent magnet synchronous motor.

[0010] Further, in step S1, the expression of the incremental extended state observer is:

[0011] ;

[0012] ;

[0013] wherein, is the increment of the d-axis current of the permanent magnet synchronous motor at the time t, is the increment of the q-axis current of the permanent magnet synchronous motor at the time t, is the increment prediction value of the d-axis current of the permanent magnet synchronous motor at the time t by the incremental extended state observer, is the increment prediction value of the q-axis current of the permanent magnet synchronous motor at the time t by the incremental extended state observer, is the increment of the d-axis voltage of the permanent magnet synchronous motor at the time t, is the increment of the q-axis voltage of the permanent magnet synchronous motor at the time t, is the increment estimation of the d-axis disturbance of the permanent magnet synchronous motor at the time t, is the increment estimation of the q-axis disturbance of the permanent magnet synchronous motor at the time t, is the predicted current of the d-axis of the permanent magnet synchronous motor at the time t, is the predicted current of the q-axis of the permanent magnet synchronous motor at the time t, is the electrical angular velocity at the time t, is the control period, is the inductance parameter used by the incremental extended state observer and the incremental DPCC controller, and are the incremental extended state observer gains, is the d-axis current of the permanent magnet synchronous motor at the time t, is the q-axis current of the permanent magnet synchronous motor at the time t, is the d-axis voltage of the permanent magnet synchronous motor at the time t, is the q-axis voltage of the permanent magnet synchronous motor at the time t, is the d-axis disturbance of the permanent magnet synchronous motor at the time t, is the q-axis disturbance of the permanent magnet synchronous motor at the time t, is the predicted current of the d-axis of the permanent magnet synchronous motor at the time t, is the predicted current of the q-axis of the permanent magnet synchronous motor at the time t, is the electrical angular velocity at the time t, is the control period, is the inductance parameter used by the incremental extended state observer and the incremental DPCC controller, and are the incremental extended state observer gains.the incremental prediction value of the d-axis current of the permanent magnet synchronous motor at time k, the predicted current of the d-axis of the permanent magnet synchronous motor at time k, the incremental estimation of the d-axis disturbance of the permanent magnet synchronous motor at time k, the incremental prediction value of the q-axis current of the permanent magnet synchronous motor at time k, the predicted current of the q-axis of the permanent magnet synchronous motor at time k, the incremental estimation of the q-axis disturbance of the permanent magnet synchronous motor at time k, the incremental prediction value of the d-axis current of the permanent magnet synchronous motor at time k, the predicted current of the d-axis of the permanent magnet synchronous motor at time k, the incremental estimation of the d-axis disturbance of the permanent magnet synchronous motor at time k, the incremental estimation of the q-axis disturbance of the permanent magnet synchronous motor at time k, the incremental prediction value of the q-axis current of the permanent magnet synchronous motor at time k, the incremental prediction value of the d-axis current of the permanent magnet synchronous motor at time k, the difference between the incremental prediction value of the d-axis current of the permanent magnet synchronous motor at time k and the incremental prediction value of the d-axis current of the permanent magnet synchronous motor at time k predicted by the incremental extended state observer, the difference between the incremental prediction value of the q-axis current of the permanent magnet synchronous motor at time k and the incremental prediction value of the q-axis current of the permanent magnet synchronous motor at time k predicted by the incremental extended state observer.

[0014] Further, the expression of the gain of the incremental extended state observer and the gain is as follows:

[0015] ;

[0016] wherein, represents the bandwidth, is a constant, and satisfies .

[0017] Further, the expression of the incremental DPCC controller in step S2 is as follows:

[0018] ;

[0019] ;

[0020] wherein, is the d-axis reference current at time k+2, is the q-axis reference current at time k+2, is the d-axis incremental reference voltage at time k, is the q-axis incremental reference voltage at time k, is the d-axis reference voltage at time k, is the d-axis reference voltage at time k, is the q-axis reference voltage at time k, is the q-axis reference voltage at time k, is the q-axis reference voltage at time k, is the q-axis reference voltage at time k, is the q-axis reference voltage at time k, is the q-axis reference voltage at time k, is​ The q-axis reference voltage at time t.

[0021] Furthermore, in step S2, the transfer function of the incremental DPCC controller... The expression is:

[0022] ;

[0023] in, , , , , , , , , , , j is the imaginary unit. This is the actual inductance value of the permanent magnet synchronous motor. , , , , , , , , , and These are all intermediate parameters and have no physical meaning. Let be the transfer function of the dq-axis current in the z-domain. Let be the transfer function of the dq-axis reference current in the z-domain. For complex variables, For bandwidth.

[0024] Furthermore, the transfer function of the incremental DPCC controller is calculated based on the incremental extended state observer, the incremental DPCC controller, and the current model of the incremental permanent magnet synchronous motor. The expression for the current model of the incremental permanent magnet synchronous motor is as follows:

[0025] ;

[0026] ;

[0027] in, For the d-axis current of the permanent magnet synchronous motor Increment of time, For the q-axis current of the permanent magnet synchronous motor Increment of time, Let be the d-axis current of the permanent magnet synchronous motor at time k. Let be the d-axis current of the permanent magnet synchronous motor at time k+1. q-axis current of the permanent magnet synchronous motor at k time, q-axis current of the permanent magnet synchronous motor at k+1 time.

[0028] Further, the transfer function between the estimated disturbance of the incremental extended state observer and the actual disturbance is expressed as:

[0029] ;

[0030] wherein, the transfer function between the estimated disturbance of the incremental extended state observer and the actual disturbance , is a complex variable.

[0031] Further, in step S3, the expression of the fixed-time gradient descent method is:

[0032] ;

[0033] wherein, is a differentiable function, is an adaptive step size, and are two coefficients for adjusting the adaptive step size , x is a position variable, is a derivative of the position variable, is a derivative of the step size, is a gradient operator, and ||·|| is a modulus operation.

[0034] Further, in step S3, in the fixed-time gradient descent method, the gradient direction is adjusted by introducing a correction sign factor:

[0035] ;

[0036] wherein, is a corrected gradient of the target function, is an inductance coefficient at k time, is a sign function, is a gradient value at the kth time after low-pass filtering.

[0037] Further, the calculation formula for identifying the inductance parameter is:

[0038] .

[0039] Compared with the prior art, the application can achieve the following beneficial effects:

[0040] The permanent magnet synchronous motor current control method based on the incremental DPCC controller provided by the application fully eliminates the influence of resistance and flux linkage parameters on the controller, and introduces an inductance self-correction mechanism, so that a truly model-free control is realized. Meanwhile, the incremental ESO proposed in the application fully utilizes the excellent disturbance suppression capability of the incremental ESO, so that the system stability, current tracking accuracy and harmonic suppression performance are all superior to those of the traditional incremental DPCC scheme. The application provides a new technical path for realizing the PMSM current loop control without relying on accurate motor parameters, while having high dynamic response capability and low current harmonic level. BRIEF DESCRIPTION OF DRAWINGS

[0041] The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0042] Figure 1 A flowchart of the permanent magnet synchronous motor current control method based on the incremental DPCC controller according to the embodiment of the application is shown in the figure;

[0043] Figure 2 A current control block diagram of the permanent magnet synchronous motor of the incremental DPCC controller according to the embodiment of the application is shown in the figure;

[0044] Figure 3 A zero-pole distribution diagram of the ratio of inductance to actual inductance of the traditional incremental DPCC controller according to the embodiment of the application is shown in the figure;

[0045] Figure 4 A zero-pole distribution diagram of the ratio of inductance to actual inductance of the incremental DPCC controller according to the embodiment of the application is shown in the figure;

[0046] Figure 5 A Bode diagram of the disturbance estimation observation error transfer function according to the embodiment of the application is shown in the figure;

[0047] Figure 6 A Bode diagram of the observed disturbance estimation transfer function according to the embodiment of the application is shown in the figure;

[0048] Figure 7 An inductance parameter self-correction flowchart according to the embodiment of the application is shown in the figure;

[0049] Figure 8 An inductance self-correction process curve diagram under the inductance mismatch condition according to the embodiment of the application is shown in the figure;

[0050] Figure 9The q-axis steady-state current output curve diagram under two different control methods described in the embodiment of the present invention;

[0051] Figure 10 The current response curve diagram of two different control methods at 0.1s reference current step when the inductance double-mismatch is not accessed and self-corrected by the inductance described in the embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and do not constitute a limitation on the present invention.

[0053] It should be noted that the embodiments in the present invention and the features in the embodiments can be combined with each other without conflict.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0055] In the description of the present invention, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood through specific circumstances.

[0056] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0057] As Figure 1As shown, this invention provides a current control method for a permanent magnet synchronous motor based on an incremental DPCC controller, specifically including the following steps: S1: Construct an incremental extended state observer, which is used to estimate the lumped disturbance of the permanent magnet synchronous motor and output the predicted current of the permanent magnet synchronous motor; S2: Construct an incremental DPCC controller based on the lumped disturbance estimation result and the predicted current output by the incremental extended state observer; S3: Use the fixed-time gradient descent method to perform inductance parameter self-correction processing on the difference between the predicted current output by the incremental extended state observer and the actual current of the permanent magnet synchronous motor, thereby obtaining the identification of the inductance parameter; S4: Feed back the identification result of the inductance parameter to the incremental extended state observer and the incremental DPCC controller, perform online identification and real-time updating of the inductance parameter, and realize robust current control of the permanent magnet synchronous motor.

[0058] It should be noted that this invention first designs an incremental extended state observer to estimate the lumped disturbance of a permanent magnet synchronous motor, improving the robustness of the incremental DPCC controller under inductor parameter mismatch conditions, and simultaneously realizing the design of an incremental DPCC controller that does not rely on the motor flux linkage and resistance parameters. Secondly, based on the incremental extended state observer, an inductor self-calibration mechanism is introduced to achieve online identification and real-time updating of inductor parameters, ensuring the accuracy of the inductor parameters used by the incremental DPCC controller and the incremental extended state observer.

[0059] Furthermore, such as Figure 2 As shown, on the one hand, when the inductance parameters of the permanent magnet synchronous motor drift during operation, the inductance self-calibration module uses the difference between the predicted current value output by the incremental ESO (abbreviation for incremental extended state observer) and the actual current value of the motor, and employs the fixed-time gradient descent method to correct the inductance parameters in the incremental DPCC controller and the incremental ESO, thereby achieving robust current control of the incremental DPCC. On the other hand, the incremental ESO provides the incremental DPCC controller with the predicted current and lumped disturbance estimate for the next moment, thereby actively suppressing the lumped disturbance in the current loop control system and providing better current control performance. Through the synergistic effect of parameter correction and disturbance suppression, this invention effectively improves the control accuracy and robustness of the current loop.

[0060] To eliminate the influence of resistance and flux linkage parameters on the control system, an incremental extended state observer for the permanent magnet synchronous motor current loop is established. The incremental extended state observer can be represented as follows:

[0061] (1);

[0062] (2);

[0063] In the formula, , These are permanent magnet synchronous motors shaft current at Increment of time, and Corresponding to and The predicted value, and It is a permanent magnet synchronous motor. shaft current at Increment in time. and These represent permanent magnet synchronous motors. Axis disturbance in Increment of time, and These represent permanent magnet synchronous motors. Axis disturbance in The increment estimate at time step. , and , These represent permanent magnet synchronous motors. Axis in Time and the Predicted current at time t. Indicates the first The electric angular velocity of the motor at any given time, Indicates the control period. These are the inductance parameters used by the incremental extended state observer and the incremental DPCC controller. and Both are bandwidth gains of incremental extended state observers.

[0064] To ensure the stability of the incremental extended state observer, and to guarantee that all its eigenvalues ​​fall within the range of... Among them Gain can be defined as:

[0065] (3);

[0066] By compensating for the total disturbance and predicted current estimated by the incremental extended state observer, the proposed incremental DPCC controller can be obtained, with the following expression:

[0067] (4);

[0068] (5);

[0069] In the formula, and They represent time k+2 respectively Shaft reference current, where and The speed is supplied by the speed loop output of the motor control system. and They represent Incremental reference voltage at time, and They represent Moment Shaft reference voltage, and They represent Moment The shaft reference voltage is inverted and then provided to the SVPWM module for processing.

[0070] To analyze the proposed incremental DPCC controller based on an incremental extended state observer, the permanent magnet synchronous motor model is incrementally modified. This is because the resistance of the permanent magnet synchronous motor... Much smaller than the ratio of inductance to sampling period And the load is an inductive load, with resistance parameters... This can be ignored. Therefore, the current model of the incremental permanent magnet synchronous motor can be simplified to:

[0071] (6);

[0072] (7);

[0073] To demonstrate that the proposed incremental extended state observer can improve tolerance to inductor mismatch, the proposed incremental DPCC controller is constructed by combining equations (1)-(7). It can be represented as:

[0074] (8);

[0075] in, , , , , , , , , , , .

[0076] like Figure 3 and Figure 4 The diagram shows the pole-zero distribution of a traditional incremental DPCC controller and the pole-zero distribution of an incremental DPCC based on an incremental ESO. The incremental ESO of this invention... It is 0.9. For example... Figure 3 As shown, when At that time, the extreme point First, when the stability boundary is crossed, the system becomes unstable. Conversely, when... As the value increases from 1 to 1.4, the three poles gradually move away from the origin; when At that time, the extreme point With the extreme point Simultaneously crossing the stability boundary, the system became unstable again. This demonstrates that, compared to traditional DPCC controllers... Compared to the stable range of the incremental DPCC controller, the inductive robustness is significantly reduced. For example... Figure 4 As shown, this invention adds a zero point and a pole, which can control the root locus direction, allowing the closed-loop pole to avoid undesirable regions. At the same time, it can pull the pole away from the boundary of the unit circle, which helps to improve the response speed of the control system. Furthermore, the tolerance of this invention for inductor parameter mismatch far exceeds that of traditional incremental DPCC controllers.

[0077] For equations (6) and (7), consider the rate of change of the d-axis due to disturbance. and the rate of change of the q-axis due to disturbance The incremental model of a permanent magnet synchronous motor, including the effects of lumped disturbances, can be expressed as:

[0078] (9);

[0079] (10);

[0080] in, Let be the d-axis current of the permanent magnet synchronous motor at time k. Let be the d-axis current of the permanent magnet synchronous motor at time k+1. Let be the q-axis current of the permanent magnet synchronous motor at time k. Let q be the q-axis current of the permanent magnet synchronous motor at time k+1.

[0081] The incremental ESO estimation perturbation is established based on equations (1), (2), (9), and (10). With actual disturbance Transfer function between :

[0082] (11);

[0083] Perturbation estimation error It can be represented as:

[0084] (12);

[0085] like Figure 5 andFigure 6 Fig. 4 shows the Bode diagram of the disturbance estimation transfer function and the disturbance estimation error transfer function of the incremental ESO and the traditional ESO, with the bandwidth of 0.9. As can be seen from Fig. 4, the disturbance observation error of the incremental ESO at low frequencies is significantly lower than that of the traditional ESO at the same bandwidth. Figure 5 As can be seen from Fig. 4, the disturbance observation error of the incremental ESO at low frequencies is significantly lower than that of the traditional ESO at the same bandwidth. Figure 5 As can be seen from Fig. 4, the disturbance observation error of the incremental ESO at low frequencies is significantly lower than that of the traditional ESO at the same bandwidth. Figure 4 As can be seen from Fig. 4, the disturbance observation error of the incremental ESO at low frequencies is significantly lower than that of the traditional ESO at the same bandwidth. Figure 5 As can be seen from Fig. 4, the disturbance observation error of the incremental ESO at low frequencies is significantly lower than that of the traditional ESO at the same bandwidth.

[0086] Next, the inductance self-correcting method based on the finite gradient descent effectively improves the inductance parameter robustness and realizes good current control effect. The relationship between the difference between the predicted current and the sampling current based on the output of the incremental ESO and the inductance mismatch is used to realize the online self-correction of the inductance parameter.

[0087] When the inductance parameter of the permanent magnet synchronous motor is mismatched, i.e. When the lumped disturbance term in the expression of the incremental ESO (incremental ESO) is ignored, by subtracting equation (1) and equation (2) from equation (6) and equation (7), the incremental current prediction error of the k+1th axis can be expressed as:

[0088] (13);

[0089] (14);

[0090] wherein, is the incremental prediction current error of the k+1th axis, is the incremental prediction current error of the k+1th axis.

[0091] ​​​Equations (13) and (14) show that at each sampling time, the incremental current prediction error is affected by inductance mismatch, and the incremental current prediction error and incremental voltage are approximately linearly related. This indicates that inductance information can be extracted from the incremental current prediction error using the incremental voltage. Therefore, this invention proposes an easy-to-implement inductance parameter extraction method based on the fixed-time gradient descent (FGM) method, which uses the error between the incremental predicted current and the actual motor current based on the incremental ESO, to improve the robustness of motor inductance parameters in the incremental DPCC controller and the incremental extended state observer.

[0092] The FGM used in this invention can be expressed as:

[0093] (15);

[0094] in, It is a differentiable function, in There is a unique extreme value at that point. It is an adaptive step size, and , It is used for adjustment The two coefficients, equation (15) will guide Move along the direction of the normalized negative gradient, and It will be dynamically adjusted according to the magnitude of the gradient. Equation (15) will converge to the desired value in a finite time. Furthermore, according to and Given the initial conditions, the convergence conditions and the upper limit of the settling time can be explicitly derived as follows:

[0095] (16);

[0096] As shown in equation (15), in order to ensure The gradient descent converges to the actual inductance value of the permanent magnet synchronous motor. It is necessary to build a connection with The relevant objective function. For convenience, let's use... Taking the axis as an example, the objective function based on equation (13) is constructed as follows:

[0097] (17);

[0098] in, express Incremental current prediction error.

[0099] (18);

[0100] because , and There is inherent fluctuation, therefore, the gradient of the objective function can change significantly, which can seriously affect the accuracy of the extracted inductance parameters. To solve this problem, a discrete low-pass filter is used to process the gradient expression in equation (18), thereby obtaining a filtered gradient expression:

[0101] (19);

[0102] wherein, and respectively represent the gradient values filtered by the low-pass filter at the k+1 moment and the k moment, represents the gradient value not filtered by the low-pass filter at the k moment, is the cut-off frequency of the low-pass filter.

[0103] To solve the factors that can cause incorrect gradient direction, such as modeling errors, low-pass filter delays, and numerical disturbances, which can occur during the gradient descent process, thereby causing the convergence of to be poor or even system instability, a correction sign factor is introduced in the present application to adjust the gradient direction, thereby ensuring the convergence and robustness of the FGM (fixed time gradient descent method):

[0104] (20);

[0105] wherein, represents a sign function, represents the corrected gradient of the objective function.

[0106] By substituting the result of equation (20) into equation (15) and performing discrete processing, a discrete form of the FGM-based identification of motor inductance parameters suitable for implementation on a digital signal processor is obtained, as follows:

[0107] (21);

[0108] The above process completes the online identification of the incremental DPCC inductance parameters, and the identification process is shown in Figure 7 . By updating the inductance parameter values obtained by identification to the parameter models of the incremental DPCC controller and the incremental extended state observer in real time, the strong robustness of the current control performance is achieved, and the model-free of the current loop controller is achieved.

[0109] Figure 8For the inductance parameter self-correction process under the condition that the current loop controller parameter mismatch is 2 times, it can be seen that the inductance self-correction can be completed in 1 second to make the incremental DPCC controller inductance parameter converge to the actual inductance parameter of the permanent magnet synchronous motor, which shows that the inductance self-correction algorithm proposed in the application can effectively solve the problem of inductance parameter mismatch when the permanent magnet synchronous motor is running.

[0110] Figure 9 The comparison results of the traditional incremental DPCC and the enhanced DPCC controller proposed in the application on the q-axis steady-state current can be seen.

[0111] Figure 10 The dynamic response curve comparison of the traditional incremental DPCC and the enhanced DPCC controller proposed in the application when the q-axis current tracks the step reference signal under the condition of not accessing the inductance self-correction method and existing 2 times inductance parameter mismatch is shown.

[0112] Therefore, the enhanced DPCC controller of the application has better anti-disturbance ability, higher tolerance to inductance mismatch and better dynamic performance than the traditional incremental DPCC.

[0113] It should be understood that the steps can be reordered, added or deleted using the various forms of flow shown above. For example, the steps described in the application disclosure can be executed in parallel, sequentially or in different order as long as the desired results of the technical solutions of the application disclosure can be achieved, which is not limited herein.

[0114] The above specific embodiments do not constitute a limitation on the protection scope of the application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent replacement and improvement within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. A current control method for a permanent magnet synchronous motor based on an incremental DPCC controller, characterized in that: Specifically, the steps include the following: S1: Construct an incremental extended state observer, which is used to estimate the lumped disturbance of the permanent magnet synchronous motor and output the predicted current of the permanent magnet synchronous motor. S2: Construct an incremental DPCC controller based on the lumped disturbance estimation results and predicted current output by the incremental extended state observer; In step S2, the expression for the incremental DPCC controller is: ； ； in, Let d be the reference current at time k+2. Let q be the reference current at time k+2. for The d-axis incremental reference voltage at time t. for The q-axis incremental reference voltage at time t. for The d-axis reference voltage at time t. for The d-axis reference voltage at time t. for The q-axis reference voltage at time t. for The q-axis reference voltage at time t; S3: The difference between the predicted current output by the incremental extended state observer and the actual current of the permanent magnet synchronous motor is processed by inductance parameter self-correction using the fixed-time gradient descent method to obtain the identification of inductance parameters. S4: Feedback the identification results of the inductance parameters to the incremental extended state observer and the incremental DPCC controller to identify and update the inductance parameters online in real time, thereby achieving robust current control of the permanent magnet synchronous motor.

2. The method for current control of a permanent magnet synchronous motor based on an incremental DPCC controller according to claim 1, characterized in that: In step S1, the expression for the incremental extended state observer is: ； ； in, For the d-axis current of the permanent magnet synchronous motor Increment of time, For the q-axis current of the permanent magnet synchronous motor Increment of time, For incremental extended state observers of the d-axis current of permanent magnet synchronous motors The incremental predicted value at time step, For incremental extended state observers of the q-axis current of permanent magnet synchronous motors The incremental predicted value at time step, For the d-axis voltage of the permanent magnet synchronous motor Increment of time, For the q-axis voltage of the permanent magnet synchronous motor Increment of time, For the d-axis disturbance of the permanent magnet synchronous motor Incremental estimation at time step, For the q-axis disturbance of the permanent magnet synchronous motor Incremental estimation at time step, For the d-axis of the permanent magnet synchronous motor in Predicted current at time of day For the q-axis of the permanent magnet synchronous motor Predicted current at time of day For the first electric angular velocity at time t, To control the cycle, The inductance parameters used by the incremental extended state observer and the incremental DPCC controller. and All are incremental extended state observer gains. For the d-axis current of the permanent magnet synchronous motor The incremental predicted value at time step, For the d-axis current of the permanent magnet synchronous motor Predicted current at time +1 For the d-axis disturbance of the permanent magnet synchronous motor Incremental estimation at time step, For the q-axis current of the permanent magnet synchronous motor The incremental predicted value at time step, For the q-axis current of the permanent magnet synchronous motor Predicted current at time of day For the q-axis disturbance of the permanent magnet synchronous motor Incremental estimation at time step, for The difference between the d-axis current increment of the permanent magnet synchronous motor at time t and the d-axis current increment predicted by the incremental extended state observer. for The difference between the q-axis current increment of the permanent magnet synchronous motor at any given time and the q-axis current increment predicted by the incremental extended state observer.

3. The current control method for a permanent magnet synchronous motor based on an incremental DPCC controller according to claim 2, characterized in that: Gain of incremental extended state observer and gain The expression is: ； in, Let the bandwidth be a constant and satisfy the condition that... .

4. The current control method for a permanent magnet synchronous motor based on an incremental DPCC controller according to claim 3, characterized in that: In step S2, the transfer function of the incremental DPCC controller The expression is: ； in, , , , , , , , , , , j is the imaginary unit. This is the actual inductance value of the permanent magnet synchronous motor. , , , , , , , , , and These are all intermediate parameters and have no physical meaning. Let be the transfer function of the dq-axis current in the z-domain. Let be the transfer function of the dq-axis reference current in the z-domain. For complex variables, For bandwidth.

5. The current control method for a permanent magnet synchronous motor based on an incremental DPCC controller according to claim 4, characterized in that: The transfer function of the incremental DPCC controller is calculated based on the incremental extended state observer, the incremental DPCC controller, and the current model of the incremental permanent magnet synchronous motor. The expression for the current model of the incremental permanent magnet synchronous motor is as follows: ； ； in, For the d-axis current of the permanent magnet synchronous motor Increment of time, For the q-axis current of the permanent magnet synchronous motor Increment of time, Let be the d-axis current of the permanent magnet synchronous motor at time k. Let be the d-axis current of the permanent magnet synchronous motor at time k+1. Let be the q-axis current of the permanent magnet synchronous motor at time k. Let q be the q-axis current of the permanent magnet synchronous motor at time k+1.

6. The current control method for a permanent magnet synchronous motor based on an incremental DPCC controller according to claim 2, characterized in that: Estimated perturbation of incremental extended state observer With actual disturbance The transfer function between them is expressed as: ； in, For the estimation of perturbations of the incremental extended state observer With actual disturbance The transfer function between them It is a complex variable.

7. The current control method for a permanent magnet synchronous motor based on an incremental DPCC controller according to claim 1, characterized in that: In step S3, the expression for the fixed-time gradient descent method is: ； in, It is a differentiable function. For adaptive step size, and For adjusting adaptive step size The two coefficients, where x is the position variable. The derivative of the position variable. The derivative of the step size, Here, ||·|| represents the gradient operator, and ||·|| represents the modulo operation.

8. The current control method for a permanent magnet synchronous motor based on an incremental DPCC controller according to claim 7, characterized in that: In step S3, in the fixed-time gradient descent method, the gradient direction is adjusted by introducing a correction sign factor: ； in, The corrected gradient for the objective function. Let be the inductance coefficient at time k. For symbolic functions, This is the gradient value after low-pass filtering at time k.

9. The current control method for a permanent magnet synchronous motor based on an incremental DPCC controller according to claim 8, characterized in that: The formula for identifying inductance parameters is as follows: 。

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