A Current Control System and Method for Permanent Magnet Synchronous Motors Based on Improved Active Disturbance Rejection

Abstract

This invention relates to a current control system and method for a permanent magnet synchronous motor based on improved active disturbance rejection, belonging to the field of motor control technology. It solves the problem of decreased steady-state and dynamic response performance when motor parameters change in existing technologies. The system includes: an extended state observer for obtaining observed values ​​of state variables; a state error feedback control module for calculating the initial control quantity; an observation error compensation module for calculating the observation error compensation quantity and feeding it back to the state error feedback control module; a model information compensation module for calculating the model compensation quantity, compensating the initial control quantity based on the model compensation quantity to obtain the final control quantity, and feeding the model compensation quantity back to the extended state observer; a limiting module for limiting the final control quantity and sending the limited control quantity to the motor current loop; and an anti-integral saturation compensation module for obtaining the anti-integral saturation compensation quantity based on the control quantities before and after limiting and feeding it back to the extended state observer.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a current control system and method for a permanent magnet synchronous motor based on improved self-disturbance rejection. Background Technology

[0002] With the rapid development of power electronics technology and control theory, permanent magnet synchronous motors (PMSMs) have been widely used in various fields such as industrial automation, new energy vehicles, and aerospace due to their high efficiency, high power density, and excellent control performance. The control method of permanent magnet synchronous motors is crucial for achieving their high-performance operation. Among these methods, current control, as the core of motor control, directly relates to the motor's dynamic response and steady-state performance.

[0003] Currently, vector control is the mainstream technology for achieving high-performance current control of permanent magnet synchronous motors. In this control strategy, the current loop controller plays a crucial role. Traditional current loop control methods, such as proportional-integral (PI) controllers, are widely used due to their simple structure and mature technology. PI controllers, by properly configuring proportional and integral parameters, can achieve rapid response and precise control of the current. However, the performance of PI controllers is limited when faced with changes in system parameters or external disturbances, making it difficult to guarantee stable and reliable control under various operating conditions.

[0004] While PI controllers perform well in many applications, they also have significant limitations. First, PI controllers are poorly adaptable to changes in system parameters. When parameters such as motor resistance, inductance, or flux linkage change due to temperature or operating conditions, PI controllers struggle to adjust their control strategies quickly and accurately, potentially leading to degraded steady-state error and dynamic response performance. Second, PI controllers may fail to provide a sufficiently rapid response to rapidly changing loads or parameter disturbances, sometimes even causing system instability. Furthermore, with the development of modern control theory, although some new control methods have emerged, such as model predictive control, while these methods offer superior performance in some aspects, they involve high computational demands, require sophisticated control hardware, and are prone to parameter mismatch issues when parameters change, affecting control performance. Therefore, designing a current control method that can adapt to parameter changes and maintain high performance under various operating conditions is a crucial technical challenge currently facing the field of permanent magnet synchronous motor control. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a current control system and method for permanent magnet synchronous motors based on self-disturbance rejection, in order to solve the problems of decreased steady-state and dynamic response performance and stability of existing current controllers when motor parameters change, as well as the integral saturation problem that may occur under high-speed and high-load conditions.

[0006] On one hand, embodiments of the present invention provide a current control system for a permanent magnet synchronous motor based on improved self-disturbance rejection. The system includes:

[0007] An extended state observer obtains state variable observations based on model compensation, anti-integral saturation compensation, actual current value, and final control quantity. The state variable observations include current observations and total disturbance observations.

[0008] The state error feedback control module is used to calculate the initial control quantity based on the current demand value, the observed state variable value, and the observation error compensation amount.

[0009] The observation error compensation module calculates the observation error compensation amount based on the actual current value and the observed current value, and feeds back the observation error compensation amount to the state error feedback control module.

[0010] The model information compensation module is used to calculate the model compensation amount based on the motor's rated parameters and the actual current value, compensate the initial control quantity based on the model compensation amount, and output the final control quantity; and to feed the model compensation amount back to the extended state observer.

[0011] The limiting module is used to limit the final control quantity and send the limited control quantity to the motor current loop;

[0012] The anti-integral saturation compensation module obtains the anti-integral saturation compensation quantity based on the control quantities before and after the amplitude limiting and feeds it back to the extended state observer.

[0013] Based on further improvements to the above system, the model of the extended state observer is specifically as follows:

[0014]

[0015] In the formula, e d1 / q1 For the current error along the d-axis or q-axis; b d / q This is the compensation factor for the d-axis or q-axis, taken as the reciprocal of the inductance along the d-axis or q-axis; u d / q β is the final control value for the d-axis or q-axis. d1 / q1 For the extended state observer gain of the d-axis or q-axis current; β d2 / q2 The extended state observer gain is the total perturbation along the d-axis or q-axis; z d1 / q1 For the observed values ​​of the d-axis or q-axis current; z d2 / q2 For the observed value of the total disturbance along the d-axis or q-axis, i d / q This represents the actual value of the d-axis or q-axis current. This represents the rate of change of the current observations along the d-axis or q-axis. k represents the rate of change of the total disturbance observations along the d-axis or q-axis. cd / cqFor the d-axis or q-axis anti-saturation gain; sat(u d / q ) represents the control quantity after limiting the d-axis or q-axis; f pd / pq This refers to the model compensation amount for the d-axis or q-axis.

[0016] Based on further improvements to the above system, the state error feedback control module calculates the initial control quantity using the following formula:

[0017]

[0018] In the formula, k d / q This refers to the proportional gain of the controller. This represents the current demand value along the d-axis or q-axis; β d1 / q1 The gain of the extended state observer for the d-axis or q-axis current.

[0019] Based on further improvements to the above system, the rated parameters of the motor include: rated shaft inductance, rated rotor permanent magnet flux linkage, and rated stator winding resistance.

[0020] The model compensation amount is calculated using the following formula:

[0021]

[0022] In the formula, f pq f is the compensation amount for the q-axis model. pd This is the compensation amount for the d-axis model. The rated rotor permanent magnet flux linkage, The rated stator winding resistance, Rated d-axis inductance, This is the rated q-axis inductance.

[0023] Based on further improvements to the above system, the final control quantity is obtained by compensating the initial control quantity using the following formula:

[0024]

[0025] Based on further improvements to the above system, the final control quantity is limited using the following formula:

[0026]

[0027] In the formula, U s，max This is a control threshold.

[0028] Based on further improvements to the above system, the anti-integral saturation compensation amount is obtained through the following formula:

[0029] Anti-integral saturation compensation amount = k cd / cq (sat(u d / q )-u d / q (6)

[0030] In the formula, k cd / cq This represents the anti-saturation gain along the d-axis or q-axis.

[0031] Based on further improvements to the above system, the observation error compensation is calculated using the following formula:

[0032] Observation error compensation amount = -β d1 / q1 e d1 / q1 (7)

[0033] On the other hand, embodiments of the present invention provide a current control method for a permanent magnet synchronous motor based on self-disturbance rejection. This method includes:

[0034] Acquire state variable observations, which include current observations and total disturbance observations;

[0035] Calculate the observation error compensation amount based on the actual current value and the observed current value;

[0036] The initial control quantity is calculated based on the current demand value, the observed state variable value, and the observation error compensation amount.

[0037] The model compensation amount is calculated based on the motor's rated parameters and the actual current value. The initial control amount is then compensated based on the model compensation amount to obtain the final control amount. The final control amount is then limited, and the limited control amount is sent to the motor current loop to achieve motor control.

[0038] Based on a further improvement of the above method, the observed values ​​of the state variables are obtained using the following formula:

[0039]

[0040] In the formula, e d1 / q1 For the current error along the d-axis or q-axis; b d / q This is the compensation factor for the d-axis or q-axis, taken as the reciprocal of the inductance along the d-axis or q-axis; u d / q β is the final control value for the d-axis or q-axis. d1 / q1 and β d2 / q2 The gain of the extended state observer for the d-axis or q-axis current and total disturbance; z d1 / q1 For the observed values ​​of the d-axis or q-axis current; z d2 / q2 For the observed value of the total disturbance along the d-axis or q-axis, i d / q This represents the actual value of the d-axis or q-axis current. This represents the rate of change of the current observations along the d-axis or q-axis. k represents the rate of change of the total disturbance observations along the d-axis or q-axis. cd / cq For the d-axis or q-axis anti-saturation gain; sat(u d / q ) represents the control quantity after limiting the d-axis or q-axis; f pd / pqThis represents the model compensation disturbance value for the d-axis or q-axis.

[0041] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0042] 1. The improved design of the active disturbance rejection observer allows the controller to be more robust to changes in motor parameters and external disturbances, reducing the dependence on an accurate system model. By expanding the total disturbance to a system state variable and observing it, various disturbances can be estimated and compensated more accurately, thereby improving control performance.

[0043] 2. By applying the observation error compensation module, under bandwidth-limited conditions, this invention can ensure that the controller has good steady-state control accuracy and effectively reduce steady-state errors caused by parameter changes.

[0044] 3. By utilizing the model information compensation module, this invention can reduce the observation pressure of the observer under bandwidth-limited conditions, and improve the dynamic response performance of the system through feedforward decoupling, so that the motor can respond quickly and accurately when facing rapid load changes or parameter disturbances.

[0045] 4. Through anti-integral saturation compensation measures, the present invention can effectively eliminate the error before and after the current controller output is limited, ensuring that the motor can operate stably under various working conditions and improving the reliability of the system.

[0046] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0047] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0048] Figure 1 This is a schematic diagram of a current control system for a permanent magnet synchronous motor based on an improved self-disturbance rejection system according to an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram of a current control system module for a permanent magnet synchronous motor based on an improved self-disturbance rejection system according to an embodiment of the present invention;

[0050] Figure 3 This is a flowchart illustrating a current control method for a permanent magnet synchronous motor based on an improved self-disturbance rejection system, according to an embodiment of the present invention. Detailed Implementation

[0051] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0052] A specific embodiment of the present invention discloses a current control system for a permanent magnet synchronous motor based on improved self-disturbance rejection, such as... Figure 1 As shown. The system includes:

[0053] An extended state observer obtains state variable observations based on model compensation, anti-integral saturation compensation, actual current value, and final control quantity. The state variable observations include current observations and total disturbance observations.

[0054] The state error feedback control module is used to calculate the initial control quantity based on the current demand value, the observed state variable value, and the observation error compensation amount.

[0055] The observation error compensation module calculates the observation error compensation amount based on the actual current value and the observed current value, and feeds back the observation error compensation amount to the state error feedback control module.

[0056] The model information compensation module is used to calculate the model compensation amount based on the motor's rated parameters and the actual current value, compensate the initial control quantity based on the model compensation amount, and output the final control quantity; and to feed the model compensation amount back to the extended state observer.

[0057] The limiting module is used to limit the final control quantity and send the limited control quantity to the motor current loop;

[0058] The anti-integral saturation compensation module obtains the anti-integral saturation compensation quantity based on the control quantities before and after the amplitude limiting and feeds it back to the extended state observer.

[0059] Specifically, the extended state observer is responsible for observing the motor current and total disturbance, providing current and total disturbance observations. The state error feedback control module calculates the initial control quantity based on the current demand value and the state variable observations provided by the extended state observer, combined with the observation error compensation amount provided by the observation error compensation module.

[0060] The observation error compensation module calculates the observation error compensation amount by comparing the actual current value and the observed current value, and feeds it back to the state error feedback control module to improve control accuracy.

[0061] The model information compensation module calculates the model compensation amount using the motor's rated parameters and the actual current value. This model compensation amount compensates for the initial control quantity, thereby generating the final control quantity. Furthermore, the model compensation amount is also fed back to the extended state observer.

[0062] To ensure system stability, the limiting module limits the final control quantity to ensure that the control quantity does not exceed the predetermined safety range, and sends the limited control quantity to the motor current loop.

[0063] During the limiting process, if the control quantity exceeds the limit value, the anti-integral saturation compensation module will calculate the anti-integral saturation compensation amount. The anti-integral saturation compensation amount is obtained based on the difference between the control quantity before and after limiting and is fed back to the extended state observer to eliminate the influence of integral saturation and prevent the system from running out of control.

[0064] Furthermore, the model of the extended state observer is shown in equation (1):

[0065]

[0066] In the formula, e d1 / q1 For the current error along the d-axis or q-axis; b d / q This is the compensation factor for the d-axis or q-axis, taken as the reciprocal of the inductance along the d-axis or q-axis; u d / q β is the final control value for the d-axis or q-axis. d1 / q1 For the extended state observer gain of the d-axis or q-axis current; β d2 / q2 The extended state observer gain is the total perturbation along the d-axis or q-axis; z d1 / q1 For the observed values ​​of the d-axis or q-axis current; z d2 / q2 For the observed value of the total disturbance along the d-axis or q-axis, i d / q This represents the actual value of the d-axis or q-axis current. This represents the rate of change of the current observations along the d-axis or q-axis. k represents the rate of change of the total disturbance observations along the d-axis or q-axis. cd / cq For the d-axis or q-axis anti-saturation gain; sat(u d / q ) represents the control quantity after limiting the d-axis or q-axis; f pd / pq This refers to the model compensation amount for the d-axis or q-axis.

[0067] Specifically, such as Figure 2 As shown, the model construction process of the extended state observer is as follows.

[0068] First, the model for generating the initial extended state observer is shown in equation (2):

[0069]

[0070] It should be noted that the voltage equation of the permanent magnet synchronous motor in the synchronous rotating coordinate system in this embodiment is shown in equation (3):

[0071]

[0072] In the formula, ud and u q For the d-axis and q-axis voltages, and L is the derivative of the actual values ​​of the current along the d-axis and q-axis. d and L q For the d-axis and q-axis inductance; ω e ψ is the electric angular velocity of the motor. f R is the flux linkage of the rotor permanent magnet; R is the resistance of the stator winding.

[0073] By rearranging equation (3), we can obtain... and As shown in equation (4):

[0074]

[0075] Combining the stator resistance voltage drop and cross-coupling terms in equation (4) yields the total disturbance value equation as shown in equation (5):

[0076]

[0077] In the formula, and The stator resistance voltage drop is for the d-axis and q-axis. and For the cross-coupling terms of the d-axis and q-axis; f d f is the total disturbance value along the d-axis. q This represents the total disturbance value along the q-axis.

[0078] b d and b q Let b be the compensation factor for the d-axis and q-axis. d =1 / L d b q =1 / L q , will b d and b q Substituting into equation (5), equation (5) can be rewritten as:

[0079]

[0080] For ease of expression, the equations of the d-axis and q-axis in equation (6) are combined into one form, as shown in equation (7);

[0081]

[0082] In the formula, f d / q b is the total disturbance value along the d-axis or q-axis. d / q u is the compensation factor for the d-axis or q-axis. d / q This represents the voltage value along the d-axis or q-axis.

[0083] The total disturbance value f along the d-axis or q-axis d / q The expansion becomes a new state variable, and the initial expanded state observer model is constructed as shown in Equation (2).

[0084] Under the initial extended state observer model, the calculated control quantity is shown in equation (8):

[0085]

[0086] In the formula, k d / q is the proportional coefficient of the controller, and is the parameter to be adjusted.

[0087] Furthermore, the extended state observer is an integral-series observer. All terms in the controlled object's mathematical model other than those in the integral-series type can be considered part of the total disturbance and observed using the high-gain extended state observer. However, when the permanent magnet synchronous motor (PMSM) operates under high-speed, high-torque conditions, its no-load back EMF and cross-coupling terms are large. Relying solely on the observer results in slow convergence speed, affecting the controller's dynamic performance. Generally, motor manufacturers provide rated parameters for the PMSM, so these parameters can be considered partially known. If the rated parameters are used to directly calculate the back EMF and cross-coupling terms, and then the extended state observer is compensated for, the observer itself only observes the inaccurate parts of the parameters. This reduces the computational burden on the extended state observer, thereby improving the dynamic performance of the PMSM-based active disturbance rejection (ADDR) current control system.

[0088] Specifically, the observer model after feeding back the model compensation amount to the extended state observer is shown in equation (9):

[0089]

[0090] In the formula, f pd / pq This refers to the model compensation amount for the d-axis or q-axis.

[0091] The model compensation amount is calculated based on the motor's rated parameters and the actual current value. The motor's rated parameters include: rated shaft inductance, rated rotor permanent magnet flux linkage, and rated stator winding resistance.

[0092] Specifically, the model compensation amounts for the d-axis and q-axis are shown in equation (10):

[0093]

[0094] In the formula, f pq f is the compensation amount for the q-axis model. pd This is the compensation amount for the d-axis model. The rated rotor permanent magnet flux linkage, The rated stator winding resistance, Rated d-axis inductance, For the rated q-axis inductance, and These are the cross-coupling terms that represent the mutual influence between the q-axis and d-axis. This is the no-load back EMF.

[0095] Furthermore, for the extended state observer, the larger its bandwidth, the smaller the observation error. However, excessive bandwidth can amplify noise and increase output glitches. On the other hand, due to the limitation of system bandwidth, the observer bandwidth cannot be expanded indefinitely. To achieve good control performance, it is necessary to calculate the observation error compensation amount based on the actual current value and the observed current value through the observation error compensation module, and feed the observation error compensation amount back to the state error feedback control module.

[0096] Specifically, the actual values ​​of the d-axis and q-axis currents i d / q Total disturbance f d / q The observation error is shown in equation (11):

[0097]

[0098] Substituting equations (8) and (11) into the equations and combining them, we get:

[0099]

[0100] The error compensation term is shown in equation (13):

[0101]

[0102] To cancel out the error compensation term, equation (12) can be transformed into:

[0103]

[0104] Equation (8) can be rewritten as:

[0105]

[0106] In practical applications, if the total disturbance observation error e d2 / q2 Since it cannot be obtained directly, it can be substituted with a known variable, and by performing a Laplace transform on equation (2), we can obtain:

[0107]

[0108] Combining equation (14) yields:

[0109] e d1 / q1 s = z d2 / q2 -β d1 / / q1 e d1 / q1 +bd / q u d / q -f d / q -b d / q u d / q

[0110] =(z d2 / q2 -f d / q )-β d1 / q1 e d1 / q1

[0111] =e d2 / q2 -β d1 / q1 e d1 / q1 (17)

[0112] Taking the inverse Laplace transform of equation (15) yields:

[0113]

[0114] Substituting equation (18) into equation (13), we get:

[0115]

[0116] Ignoring the differential term in equation (19), we get:

[0117]

[0118] In practical implementation, when the proportional gain of the controller is large, -k d / q e d1 / q1 The term can easily destabilize the system, so it is only applicable to -β. d1 / q1 e d1 / q1 The compensation can be performed on the item, and the formula for obtaining the observation error compensation amount is:

[0119] Observation error compensation amount = -β d1 / q1 e d1 / q1 (twenty one)

[0120] Based on the observation error compensation amount, the control quantity under the initial extended state observer model shown in equation (8) is compensated to obtain the initial control quantity as shown in equation (22):

[0121]

[0122] Furthermore, the initial control quantity is compensated based on the model compensation quantity to obtain the final control quantity as shown in equation (23):

[0123]

[0124] Furthermore, due to the limitation of the DC bus voltage, the motor may experience over-modulation under some extreme operating conditions, such as high torque demand and high speed, making it difficult for the drive motor system to maintain stable operation. Therefore, it is necessary to limit the final control quantity according to the DC bus voltage, as shown in equation (24):

[0125]

[0126] In the formula, U s，max This is a control threshold.

[0127] When the control quantity after amplitude limiting is sat(u) d ) and sat(u q Exceeding the control threshold U s,max When the system is in a state of saturation, it is called integral saturation. In this case, the motor may run out of control and "run away". The anti-integral saturation compensation module obtains the anti-integral saturation compensation quantity based on the control quantity before and after the limit and feeds it back to the extended state observer. The error is eliminated by the error-free regulation of the integral link, so that the controller exits the saturation state.

[0128] The anti-integral saturation compensation amount is shown in equation (25):

[0129] Anti-integral saturation compensation amount = k cd / cq (sat(u d / q )-u d / q (25)

[0130] Furthermore, the final tensor state observer is obtained by compensating the extended state observer based on the anti-integral saturation compensation amount, as shown in equation (26):

[0131]

[0132] Compared with existing technologies, this embodiment provides a permanent magnet synchronous motor current control system based on active disturbance rejection. The observation error compensation module dynamically adjusts the compensation amount by calculating the difference between the actual and observed current values, ensuring high-precision control under bandwidth-constrained conditions. The model information compensation module uses the motor's rated parameters and actual current values ​​to calculate the compensation amount to optimize the dynamic response, further enhancing the system's performance under bandwidth-constrained conditions. The limiting module limits the final control quantity to avoid overmodulation and ensure system stability. The anti-integral saturation compensation module calculates and feeds back the compensation amount to the extended state observer based on the difference in control quantity before and after limiting, effectively eliminating the effects of integral saturation and ensuring stable system operation under extreme conditions such as high speed and high load.

[0133] Another specific embodiment of the present invention discloses a current control method for a permanent magnet synchronous motor based on improved self-disturbance rejection, such as... Figure 3 As shown. The method includes:

[0134] Acquire state variable observations, which include current observations and total disturbance observations;

[0135] Calculate the observation error compensation amount based on the actual current value and the observed current value;

[0136] The initial control quantity is calculated based on the current demand value, the observed state variable value, and the observation error compensation amount.

[0137] The model compensation amount is calculated based on the motor's rated parameters and the actual current value. The final control amount is obtained by compensating the initial control amount based on the model compensation amount.

[0138] The final control quantity is limited, and the limited control quantity is sent to the motor current loop to achieve motor control.

[0139] It is understandable that this current control method for permanent magnet synchronous motors based on improved self-disruption rejection is similar to the reference method. Figure 2 The various modules in the current control system for permanent magnet synchronous motors based on improved active disturbance rejection described herein will not be elaborated upon here.

[0140] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0141] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A current control system for a permanent magnet synchronous motor based on improved self-disturbance rejection, characterized in that, The system includes: An extended state observer obtains state variable observations based on model compensation, anti-integral saturation compensation, actual current value, and final control quantity. The state variable observations include current observations and total disturbance observations. The state error feedback control module is used to calculate the initial control quantity based on the current demand value, the observed state variable value, and the observation error compensation amount. The observation error compensation module calculates the observation error compensation amount based on the actual current value and the observed current value, and feeds back the observation error compensation amount to the state error feedback control module. The model information compensation module is used to calculate the model compensation amount based on the motor's rated parameters and the actual current value, compensate the initial control quantity based on the model compensation amount, and output the final control quantity; and to feed the model compensation amount back to the extended state observer. The limiting module is used to limit the final control quantity and send the limited control quantity to the motor current loop; The anti-integral saturation compensation module obtains the anti-integral saturation compensation quantity based on the control quantities before and after the amplitude limiting and feeds it back to the extended state observer; wherein, the model of the extended state observer is specifically as follows: （1） In the formula, For the current error of the d-axis or q-axis; This is the compensation factor for the d-axis or q-axis, taken as the reciprocal of the inductance along the d-axis or q-axis. This is the final control value for the d-axis or q-axis; For the extended state observer gain of the d-axis or q-axis current; The extended state observer gain is the total perturbation along the d-axis or q-axis. These are the observed values ​​of the d-axis or q-axis current; For the observed values ​​of the total disturbance along the d-axis or q-axis, This represents the actual value of the d-axis or q-axis current. This represents the rate of change of the current observations along the d-axis or q-axis. This represents the rate of change of the total disturbance observations along the d-axis or q-axis. For the d-axis or q-axis anti-saturation gain; This is the control quantity after limiting the d-axis or q-axis; This refers to the model compensation amount for the d-axis or q-axis; The final control quantity is obtained by compensating the initial control quantity using the following formula: （2） In the formula, This refers to the proportional gain of the controller. This represents the current requirement value for the d-axis or q-axis. For the extended state observer gain of the d-axis or q-axis current; The final control value is limited using the following formula: （3） In the formula, This is a control threshold.

2. The current control system for a permanent magnet synchronous motor based on improved self-disturbance rejection as described in claim 1, characterized in that, The state error feedback control module calculates the initial control quantity using the following formula: （4）。 3. The current control system for a permanent magnet synchronous motor based on improved self-disturbance rejection as described in claim 2, characterized in that, The rated parameters of the motor include: rated shaft inductance, rated rotor permanent magnet flux linkage, and rated stator winding resistance; The model compensation amount is calculated using the following formula: （5） In the formula, This is the compensation amount for the q-axis model. This is the compensation amount for the d-axis model. The rated rotor permanent magnet flux linkage, The rated stator winding resistance, Rated d-axis inductance, This is the rated q-axis inductance.

4. The current control system for a permanent magnet synchronous motor based on improved self-disturbance rejection as described in claim 1, characterized in that, The anti-integral saturation compensation amount is obtained using the following formula: Anti-integral saturation compensation amount = (6) In the formula, This represents the anti-saturation gain along the d-axis or q-axis.

5. The current control system for a permanent magnet synchronous motor based on improved self-disturbance rejection as described in claim 2, characterized in that, The observation error compensation amount is calculated using the following formula: Observation error compensation amount = (7).

6. A current control method for a permanent magnet synchronous motor based on improved self-disturbance rejection, applied to the system described in any one of claims 1-5, characterized in that, The method includes: Acquire state variable observations, including current observations and total disturbance observations; Calculate the observation error compensation amount based on the actual current value and the observed current value; The initial control quantity is calculated based on the current demand value, the observed state variable value, and the observation error compensation amount. The model compensation amount is calculated based on the motor's rated parameters and the actual current value. The initial control amount is then compensated based on the model compensation amount to obtain the final control amount. The final control amount is then limited, and the limited control amount is sent to the motor current loop to achieve motor control.

7. The current control method for permanent magnet synchronous motors based on improved self-disturbance rejection as described in claim 6, characterized in that, The observed values ​​of the state variables are obtained using the following formula: （8） In the formula, For the current error of the d-axis or q-axis; This is the compensation factor for the d-axis or q-axis, taken as the reciprocal of the inductance along the d-axis or q-axis. This is the final control value for the d-axis or q-axis; and The gain of the extended state observer for the d-axis or q-axis current and total disturbance; These are the observed values ​​of the d-axis or q-axis current; For the observed values ​​of the total disturbance along the d-axis or q-axis, This represents the actual value of the d-axis or q-axis current. This represents the rate of change of the current observations along the d-axis or q-axis. This represents the rate of change of the total disturbance observations along the d-axis or q-axis. For the d-axis or q-axis anti-saturation gain; This is the control quantity after limiting the d-axis or q-axis; This represents the model compensation disturbance value for the d-axis or q-axis.

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