A self-disturbance current tracking control method for permanent magnet synchronous motor simulator

Abstract

The application provides a current tracking control method for a permanent magnet synchronous motor simulator, and the method can effectively maintain system stability and enhance the robustness of the control system through the active disturbance rejection control mode. In the method, the stability is analyzed by combining the bandwidth method of the linear active disturbance rejection control, and the parameter setting can be completed by only setting the bandwidth. The control structure is clear, and the parameter setting is convenient. A nonlinear extended state observer is established for the error in the active disturbance rejection control, and the error processing has the characteristics of'small error and large gain, and large error and small gain', so that the anti-interference performance of the system can be significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of hardware-in-the-loop testing technology for permanent magnet synchronous motors, specifically relating to a self-disruption current tracking control method for a permanent magnet synchronous motor simulator. Background Technology

[0002] Motor simulators are commonly used controller-in-the-loop (CIL) test platforms for motors. They combine power devices and digital simulation to test the power level of motor controllers. The power device component mainly includes interface circuits, a power-level inverter, and sensors. The digital simulation component mainly includes a motor model, a current tracking control algorithm, and a PWM modulation algorithm. The digital simulation part outputs control signals to control the power-level inverter, achieving power interaction in the electric drive system under test, thus simulating the operation of a real motor. The current tracking control algorithm is the core of the motor simulator. Currently, most implementations use traditional PID control to achieve interface current tracking control. However, PID control suffers from a strong dependence on parameter matching results, failing to effectively suppress time-varying disturbances within the system, and easily leading to system oscillations and control saturation, thus failing to meet the requirements of motor simulators. Summary of the Invention

[0003] In view of this, and to address the technical problems existing in this field, the present invention provides a self-disturbance rejection current tracking control method for a permanent magnet synchronous motor simulator, comprising the following steps:

[0004] a) Establish the voltage equations for the L-type interface circuit in the dq coordinate system:

[0005]

[0006] In the formula, u d u q For the d-axis and q-axis voltage components of the driver-side input interface; v d v q For the d-axis and q-axis voltage components on the motor simulator side; i d i q ω represents the d-axis and q-axis current components. e R is the electric angular velocity of the motor rotor. f For the phase resistance of the interface circuit; L f The inductance of the interface circuit is t; t is the time variable.

[0007] b) Transform the interface circuit voltage equation in the dq coordinate system into state-space form, and simplify the state equation into disturbance form to obtain the following state-space equation in the form of active disturbance rejection control:

[0008]

[0009]

[0010] In the formula, b0 = -1 / L f This represents the estimated value of the control quantity gain; the control quantity u is the expected dq axis output voltage of the inverter on the simulator side. The remaining part of the voltage equation of the interface circuit, excluding the control quantity and the control quantity gain, is defined as the system disturbance f, which includes external disturbance and internal disturbance.

[0011] c) For the state equations of the interface circuit, the known and unknown disturbances are expanded into new state variables, resulting in the following state-space equations:

[0012]

[0013] In the formula, u = v d , C = [1 0], D = 0, where the superscript indicates the derivative of the corresponding parameter;

[0014] The following extended state observer is designed for this state equation:

[0015]

[0016] In the formula, L=[β d1 β d2 ] T Let β be the observer gain matrix. d1 β d2 All are observer gains; by simplifying the above equation, the equation for the d-axis current linear extended state observer (LESO) based on active disturbance rejection control is established:

[0017]

[0018] In the formula, z d1 For the observed value of the d-axis current, z d2 Let f be the observed value of the system disturbance, and e2 be the error;

[0019] d) The error e2 is processed using a nonlinear function, and the following nonlinear extended state observer (NLESO) is built to improve the control effect:

[0020]

[0021] The actual control effect can be adjusted by selecting the values ​​of parameters α and δ in the formula;

[0022] The design control rate of the system is determined using proportional control:

[0023]

[0024] In the formula, r d The target d-axis current value is calculated from the motor model and obtained through coordinate transformation; u is the target d-axis voltage control output; K p The gain is proportionally controlled; u0 is an intermediate variable.

[0025] e) Determine parameter tuning rules and controller stability conditions by performing stability analysis on the control system and observer;

[0026] First, the stability of the linearly extended state observer is analyzed, and the following error matrix is ​​established:

[0027]

[0028] When the eigenvalues ​​of A-LC are negative, the observer is stable. The bandwidth method is used for parameter tuning, and the transfer function poles are configured as multiple poles on the real axis.

[0029] |λI-(A-LC)|=(λ+ω o ) 3

[0030] Where λ is the system characteristic root;

[0031] The parameter tuning result is then obtained as: β d1 =2ω o ,β d2 =ω o 2 When the observer bandwidth ω o When the value is greater than 0, the stability condition of the Hurwitz criterion is satisfied, proving that the extended state observer is stable;

[0032] Once the observer satisfies the stability condition, the pole z d1 ≈y、z d2 ≈f, to analyze the global stability of the active disturbance rejection control, the system differential equation is... Simplified to: The transfer function of the closed-loop system then simplifies to:

[0033]

[0034] Where r(s) is the target current input, and s represents the Laplace operator;

[0035] When K p When the value is greater than 0, the control system reaches stability;

[0036] For the q-axis current, active disturbance rejection control is implemented in the same way as in steps c) to e).

[0037] By executing the method provided by the present invention through corresponding hardware, the following permanent magnet synchronous motor simulator can be constructed as a current tracking control module. Specifically, it consists of a permanent magnet synchronous motor model on the simulator side, a PWM modulation module, a current tracking control module, an inverter and interface circuit, as well as a drive-side inverter and a controller for the motor under test.

[0038] The permanent magnet synchronous motor model acquires the three-phase voltage output from the motor controller under test and outputs the target three-phase current to the current tracking control module. Simultaneously, the interface circuit provides current sampling values ​​to the current tracking control module based on the three-phase voltage. The current tracking control module performs coordinate transformation and active disturbance rejection control based on the input signal, outputs the desired αβ axis voltage to the PWM modulation module, and enables the PWM modulation module to perform SVPWM modulation and output 6-channel switching control signals to the inverter. By controlling the three-phase voltage on both sides of the interface circuit, the current sampling values ​​are tracked to the target three-phase current, compensating for disturbances in the system, and simultaneously feeding back the motor speed and angle to the motor controller under test.

[0039] The active disturbance rejection current tracking control method for a permanent magnet synchronous motor simulator provided by the present invention effectively maintains system stability and enhances the robustness of the control system through active disturbance rejection control. The method incorporates the linear active disturbance rejection control bandwidth method for stability analysis, requiring only bandwidth tuning to complete parameter tuning. The control structure is clear, and parameter tuning is relatively convenient. A nonlinear extended state observer is established to address errors in the active disturbance rejection control, exhibiting the characteristic of "large gain for small errors and small gain for large errors," thereby significantly improving the system's anti-interference performance. Attached Figure Description

[0040] Figure 1 The topology of a permanent magnet synchronous motor simulator system based on the method provided in this invention;

[0041] Figure 2 A flowchart of the method provided by the present invention;

[0042] Figure 3 This is a block diagram of the method provided by the present invention for active disturbance rejection tracking control of the dq axis current. Detailed Implementation

[0043] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The self-disturbance rejection current tracking control method for a permanent magnet synchronous motor simulator provided by this invention, such as... Figure 2 As shown, perform the following steps in sequence:

[0045] a) Establish the voltage equations for the L-type interface circuit in the dq coordinate system:

[0046]

[0047] In the formula, u d u q For the d-axis and q-axis voltage components of the driver-side input interface; v d v q For the d-axis and q-axis voltage components on the motor simulator side; i d i q ω represents the d-axis and q-axis current components. e R is the electric angular velocity of the motor rotor. f For the phase resistance of the interface circuit; L f The inductance of the interface circuit is t; t is the time variable.

[0048] b) Transform the interface circuit voltage equation in the dq coordinate system into state-space form, and simplify the state equation into disturbance form to obtain the following state-space equation in the form of active disturbance rejection control:

[0049]

[0050]

[0051] In the formula, b0 = -1 / L f This represents the estimated value of the control quantity gain; the control quantity u is the expected dq axis output voltage of the inverter on the simulator side. The remaining part of the voltage equation of the interface circuit, excluding the control quantity and the control quantity gain, is defined as the system disturbance f, which includes external disturbance and internal disturbance.

[0052] c) For the state equations of the interface circuit, the known and unknown disturbances are expanded into new state variables, resulting in the following state-space equations:

[0053]

[0054] In the formula, u = v d , C = [1 0], D = 0, where the superscript indicates the derivative of the corresponding parameter;

[0055] The following extended state observer is designed for this state equation:

[0056]

[0057] In the formula, L=[βd1 β d2 ] T Let β be the observer gain matrix. d1 β d2 All are observer gains; by simplifying the above equation, the equation for the d-axis current linear extended state observer (LESO) based on active disturbance rejection control is established:

[0058]

[0059] In the formula, z d1 For the observed value of the d-axis current, z d2 Let f be the observed value of the system disturbance, and e2 be the error;

[0060] d) The error e2 is processed using a nonlinear function, and the following nonlinear extended state observer (NLESO) is built to improve the control effect:

[0061]

[0062] The actual control effect can be adjusted by selecting the values ​​of parameters α and δ in the formula;

[0063] The design control rate of the system is determined using proportional control:

[0064]

[0065] In the formula, r d The target d-axis current value is calculated from the motor model and obtained through coordinate transformation; u is the target d-axis voltage control output; K p The gain is proportionally controlled; u0 is an intermediate variable.

[0066] e) Determine parameter tuning rules and controller stability conditions by performing stability analysis on the control system and observer;

[0067] First, the stability of the linearly extended state observer is analyzed, and the following error matrix is ​​established:

[0068]

[0069] When the eigenvalues ​​of A-LC are negative, the observer is stable. The bandwidth method is used for parameter tuning, and the transfer function poles are configured as multiple poles on the real axis.

[0070] |λI-(A-LC)|=(λ+ω o ) 3

[0071] Where λ is the system characteristic root;

[0072] The parameter tuning result is then obtained as: β d1 =2ω o ,β d2 =ω o 2 When the observer bandwidth ω o When the value is greater than 0, the stability condition of the Hurwitz criterion is satisfied, proving that the extended state observer is stable;

[0073] Once the observer satisfies the stability condition, the pole z d1 ≈y、z d2 ≈f, to analyze the global stability of the active disturbance rejection control, the system differential equation is... Simplified to: The transfer function of the closed-loop system then simplifies to:

[0074]

[0075] Where r(s) is the target current input, and s represents the Laplace operator;

[0076] When K p When k > 0, the control system reaches stability; where k p =ω c Controller bandwidth ω c The observer bandwidth ω determines the controller's response speed. o This determines the observer's tracking speed. Since the observer is the inner loop of the controller, to ensure system convergence, the observer bandwidth ω must be guaranteed. o For controller bandwidth ω c It needs to be 3 to 5 times faster to ensure a better tracking effect.

[0077] For the q-axis current, active disturbance rejection control is implemented in the same manner as in steps c) to e). Specifically, the active disturbance rejection control framework for the dq-axis is as follows: Figure 3 As shown.

[0078] By executing the method provided by the present invention using appropriate hardware, a permanent magnet synchronous motor simulator can be constructed as a current tracking control module, the system framework of which is as follows: Figure 1 As shown, it consists of a heterogeneous implementation processor, inverter and interface circuit on the simulator side that runs a permanent magnet synchronous motor model, a PWM modulation module, a current tracking control module, and a drive-side inverter and a controller for the motor under test.

[0079] The permanent magnet synchronous motor model acquires the three-phase voltage output from the motor controller under test and outputs the target three-phase current to the current tracking control module. Simultaneously, the interface circuit provides current sampling values ​​to the current tracking control module based on the three-phase voltage. The current tracking control module performs coordinate transformation and active disturbance rejection control based on the input signal, outputs the desired αβ axis voltage to the PWM modulation module, and enables the PWM modulation module to perform SVPWM modulation and output 6-channel switching control signals to the inverter. By controlling the three-phase voltage on both sides of the interface circuit, the current sampling values ​​are tracked to the target three-phase current, compensating for disturbances in the system, and simultaneously feeding back the motor speed and angle to the motor controller under test.

[0080] It should be understood that the sequence number of each step in the embodiments of the present invention does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for self-disturbance rejection current tracking control for a permanent magnet synchronous motor simulator, characterized in that: Perform the following steps in sequence: a) Establish the voltage equations for the L-type interface circuit in the dq coordinate system: In the formula, u d u q For the d-axis and q-axis voltage components of the driver-side input interface; v d v q For the d-axis and q-axis voltage components on the motor simulator side; i d i q ω represents the d-axis and q-axis current components. e R is the electric angular velocity of the motor rotor. f For the phase resistance of the interface circuit; L f For the interface circuit phase inductance; t is a time variable; b) Transform the interface circuit voltage equation in the dq coordinate system into state-space form, and simplify the state equation into disturbance form to obtain the following state-space equation in the form of active disturbance rejection control: In the formula, b0 = -1 / L f This represents the estimated value of the control quantity gain; the control quantity u is the expected dq axis output voltage of the inverter on the simulator side. The remaining part of the voltage equation of the interface circuit, excluding the control quantity and the control quantity gain, is defined as the system disturbance f, which includes external disturbance and internal disturbance. c) For the state equations of the interface circuit, the known and unknown disturbances are expanded into new state variables, resulting in the following state-space equations: In the formula, u = v d , C = [1 0], D = 0, where the superscript indicates the derivative of the corresponding parameter; The following extended state observer is designed for this state equation: In the formula, L=[β d1 β d2 ] T Let β be the observer gain matrix. d1 β d2 All are observer gains; by simplifying the above equation, we establish the d-axis current linear expansion state observer equation based on active disturbance rejection control: In the formula, z d1 For the observed value of the d-axis current, z d2 Let f be the observed value of the system disturbance, and e2 be the error; d) The error e2 is processed using a nonlinear function, and the following nonlinear extended state observer is built to improve the control effect: The actual control effect can be adjusted by selecting the values ​​of parameters α and δ in the formula; The design control rate of the system is determined using proportional control: In the formula, r d The target d-axis current value is calculated from the motor model and obtained through coordinate transformation; u is the target d-axis voltage control output; K p The gain is proportionally controlled; u0 is an intermediate variable. e) Determine parameter tuning rules and controller stability conditions by performing stability analysis on the control system and observer; First, the stability of the linearly extended state observer is analyzed, and the following error matrix is ​​established: When the eigenvalues ​​of A-LC are negative, the observer is stable. The bandwidth method is used for parameter tuning, and the transfer function poles are configured as multiple poles on the real axis. |λI-(A-LC)|=(λ+ω o ) 3 Where λ is the system characteristic root; The parameter tuning result is then obtained as: β d1 =2ω o ,β d2 =ω o 2 When the observer bandwidth ω o When the value is greater than 0, the stability condition of the Hurwitz criterion is satisfied, proving that the extended state observer is stable; Once the observer satisfies the stability condition, the pole z d1 ≈y、z d2 ≈f, to analyze the global stability of the active disturbance rejection control, the system differential equation is... Simplified to: The transfer function of the closed-loop system then simplifies to: Where r(s) is the target current input, and s represents the Laplace operator; When K p When the value is greater than 0, the control system reaches stability; For the q-axis current, active disturbance rejection control is implemented in the same way as in steps c) to e).

2. A permanent magnet synchronous motor simulator based on active disturbance rejection control, characterized in that: It consists of a permanent magnet synchronous motor model on the simulator side, a PWM modulation module, a current tracking control module that executes the method as described in claim 1, an inverter and interface circuit, as well as a drive-side inverter and a controller for the motor under test; The permanent magnet synchronous motor model acquires the three-phase voltage output from the motor controller under test and outputs the target three-phase current to the current tracking control module. Simultaneously, the interface circuit provides current sampling values ​​to the current tracking control module based on the three-phase voltage. The current tracking control module performs coordinate transformation and active disturbance rejection control based on the input signal, outputs the desired αβ axis voltage to the PWM modulation module, and enables the PWM modulation module to perform SVPWM modulation and output 6-channel switching control signals to the inverter. By controlling the three-phase voltage on both sides of the interface circuit, the current sampling values ​​are tracked to the target three-phase current, compensating for disturbances in the system, and simultaneously feeding back the motor speed and angle to the motor controller under test.

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