CN-121984366-A - High-reliability complex coefficient repeated control grid-connected inverter control system and method suitable for power supply protection scene

CN121984366ACN 121984366 ACN121984366 ACN 121984366ACN-121984366-A

Abstract

The invention discloses a control system and a method for a high-reliability complex coefficient repeated control grid-connected inverter suitable for a power supply-protected scene, comprising the steps of establishing an LCL type grid-connected inverter mathematical model under an alpha beta static coordinate system aiming at a three-phase grid-connected inverter, omitting Park conversion and decoupling calculation under a dq coordinate system; the complex coefficient filter H(s) and the complex coefficient repetitive controller are designed to form a double-input and double-output control structure, the gain of the controller at the fundamental frequency is infinite by setting the imaginary part omega m of the complex coefficient equal to the fundamental frequency omega 0, the complete tracking of the periodic signal is realized, and the dynamic response capability of the system is improved by combining an output feedback control law. The invention can effectively inhibit unbalanced voltage and harmonic pollution on the grid side, remarkably reduce the THD of grid-connected current, has good dynamic control performance and robustness, is suitable for new energy grid-connected power generation systems such as solar energy, wind energy and the like, and has important supporting function on improving the power supply reliability and the power-preserving capability of the power system under the condition of accessing new energy.

Inventors

ZHAO WEICHENG
CHANG WENTAO
CAO XIN
CAO MAOSEN
QIN YIWEN
PENG WENJIE
WANG WENTAO
WANG LINGSHUANG
HAN ZHI
CHEN JIAYUAN
XIE LI
MA HAOYUAN

Assignees

国网四川省电力公司营销服务中心
四川蜀能电力有限公司检验检测分公司

Dates

Publication Date: 20260505
Application Date: 20260109

Claims (10)

1. The utility model provides a high reliability complex coefficient repetitive control grid-connected inverter control system suitable for power supply scene, its characterized in that includes: the state space model building module is used for building a state space model representing the dynamic characteristics of the LCL type three-phase grid-connected inverter based on the topological structure and circuit parameters of the LCL type three-phase grid-connected inverter, and obtaining the grid-connected three-phase current of the power grid side of the LCL type three-phase grid-connected inverter according to the state space model of the LCL type three-phase grid-connected inverter; the current error signal generation module is used for converting the network-connected three-phase current into a current component under an alpha beta coordinate system through Clarke transformation to obtain an alpha-axis current component and a beta-axis current component, taking the difference between a preset alpha-axis reference current and the alpha-axis current component as an alpha-axis error current, and taking the difference between the preset beta-axis reference current and the beta-axis current component as a beta-axis error current; the complex coefficient repetition control module is used for performing difference processing according to the alpha-axis error current and the beta-axis error current in the current control period and the alpha-axis compensation voltage control quantity and the beta-axis compensation voltage control quantity obtained by the complex coefficient filter in the previous current control period to obtain an intermediate state alpha-axis compensation voltage control quantity and an intermediate state beta-axis compensation voltage control quantity, and performing filtering processing on the intermediate state alpha-axis compensation voltage control quantity and the intermediate state beta-axis compensation voltage control quantity by using the complex coefficient filter to obtain the alpha-axis compensation voltage control quantity and the beta-axis compensation voltage control quantity in the current control period; The control voltage acquisition module is used for acquiring an alpha-axis voltage control quantity and a beta-axis voltage control quantity according to a composite cooperative control law, an alpha-axis current component, a beta-axis current component, an alpha-axis compensation voltage control quantity of a current control period and a beta-axis compensation voltage control quantity of the current control period which are obtained through offline calibration in advance; The modulation signal conversion module is used for converting the alpha-axis voltage control quantity and the beta-axis voltage control quantity into three-phase modulation voltage signals through Clarke inverse transformation, and generating driving signals of the LCL type three-phase grid-connected inverter through the three-phase modulation voltage signals and a space vector pulse width modulation method.
2. The high-reliability complex coefficient repeated control grid-connected inverter control system suitable for the power supply protection scene of claim 1, wherein the method for establishing a state space model representing the dynamic characteristics of the LCL type three-phase grid-connected inverter under an alpha beta static coordinate system based on the topological structure and circuit parameters of the LCL type three-phase grid-connected inverter and obtaining the grid-connected three-phase current of the grid side of the LCL type three-phase grid-connected inverter according to the state space model of the LCL type three-phase grid-connected inverter comprises the following steps: ; Wherein, the For the state vector, T is the transpose operator, m=a, b, c, Is the a-phase current of the inversion side of the LCL type three-phase grid-connected inverter, Is the b-phase current of the inversion side of the LCL type three-phase grid-connected inverter, Is the c-phase current of the inversion side of the LCL type three-phase grid-connected inverter, Is the a-phase capacitance voltage of the LCL type three-phase grid-connected inverter, Is the b-phase capacitor voltage of the LCL type three-phase grid-connected inverter, Is the c-phase capacitor voltage of the LCL type three-phase grid-connected inverter, Is the power grid side a-phase current of the LCL type three-phase grid-connected inverter, Is the b-phase current at the power grid side of the LCL type three-phase grid-connected inverter, The current is c-phase current at the power grid side of the LCL type three-phase grid-connected inverter; In order to input the vector(s), The voltage is output by a phase bridge arm of the LCL type three-phase grid-connected inverter, The output voltage of the b-phase bridge arm of the LCL type three-phase grid-connected inverter, The voltage is output by a c-phase bridge arm of the LCL type three-phase grid-connected inverter; For disturbance vector containing power grid voltage item, A is system matrix containing inductance, capacitance and parasitic resistance parameter, B is input matrix determined by inversion side inductance, C is LCL type three-phase grid-connected inverter power grid side current output matrix, Is LCL type three-phase grid-connected inverter network three-phase current on the power grid side.
3. The high-reliability complex-coefficient repetitive-control grid-connected inverter control system suitable for a power supply scene as claimed in claim 2, wherein the method for converting the network-connected three-phase current into current components under an alpha-beta coordinate system through Clarke transformation to obtain an alpha-axis current component and a beta-axis current component comprises the following steps: , ; Wherein, the Is the alpha-axis current component in the alpha beta coordinate system, Is the beta-axis current component in the alpha beta coordinate system, Is the power grid side a-phase current of the LCL type three-phase grid-connected inverter, Is the b-phase current at the power grid side of the LCL type three-phase grid-connected inverter, The current is c-phase current at the power grid side of the LCL type three-phase grid-connected inverter.
4. The high-reliability complex-coefficient repetitive-control grid-connected inverter control system suitable for a power supply protection scene as claimed in claim 3, wherein the method for obtaining the alpha-axis compensation voltage control quantity and the beta-axis compensation voltage control quantity of the current control period by performing difference processing according to the alpha-axis error current and the beta-axis error current of the current control period and the alpha-axis compensation voltage control quantity and the beta-axis compensation voltage control quantity obtained by a complex-coefficient filter of the previous current control period to obtain the intermediate alpha-axis compensation voltage control quantity and the intermediate beta-axis compensation voltage control quantity, and performing filtering processing on the intermediate alpha-axis compensation voltage control quantity and the intermediate beta-axis compensation voltage control quantity by using the complex-coefficient filter comprises the following steps: ; ; ; Wherein, the Representing a difference signal generated after comparing the current period error with the history memory information for the intermediate calculated variable of the complex coefficient repetitive controller at the time t, As the alpha-axis error current, As the beta-axis error current, Is that The intermediate state alpha axis of time compensates the voltage control quantity, Is that The intermediate beta-axis of time compensates the voltage control quantity, The voltage control quantity is compensated for the intermediate state alpha axis at the moment t, Compensating the voltage control quantity for the intermediate beta-axis at the time t, The voltage control quantity is compensated for the alpha-axis at the time t, The voltage control quantity is compensated for the beta axis at the time t, As a transfer function of the complex coefficient filter, For the period of the current control, And outputting a voltage control signal for the complex coefficient repetitive controller.
5. The high-reliability complex-coefficient repetitive-control grid-connected inverter control system applicable to power conservation scenes as claimed in claim 4, wherein the transfer function of the complex-coefficient filter is as follows: ; Compensating the alpha-axis compensation voltage control quantity at the moment t Beta-axis compensation voltage control at time t as real part of complex signal As the imaginary part of the complex signal For a pair of Laplace transformation is carried out on two sides of the equation of (2) to obtain , Will be Substitution into The method comprises the following steps: ; Combined stand And (3) with The method comprises the following steps: ; For a pair of Performing Laplace inverse transformation to obtain differential equation of complex coefficient filter for solving alpha-axis compensation voltage control quantity Beta-axis compensation voltage control amount : ; Where ωc is the filter cut-off frequency, As an imaginary part parameter, ω0 is the fundamental angular frequency of the grid, Is a complex number of variables, which are the same as the variables, In units of imaginary numbers, In the case of the hilbert transform, Is that Is used for the Laplace transformation of (2), Is that Is used for the Laplace transformation of (2), Is that Is used for the Laplace transformation of (2), Is that Is used for the Laplace transformation of (2), The voltage control quantity is compensated for the intermediate state alpha axis at the moment t, Compensating the voltage control quantity for the intermediate beta-axis at the time t, The voltage control quantity is compensated for the alpha-axis at the time t, To compensate the voltage control quantity for the beta axis at the time t, The first derivative of the voltage control quantity is compensated for the intermediate alpha-axis at time t, The first derivative of the voltage control quantity is compensated for the intermediate beta-axis at time t.
6. The system of claim 4, wherein the method for obtaining the pre-off-line calibrated composite cooperative control law comprises the steps of forming the composite cooperative control law by a state space model of the LCL type three-phase grid-connected inverter, a composite coefficient repetitive controller and the composite cooperative control law, solving by using the linear matrix inequality LMI with the Lyapunov stability theory as a constraint condition to obtain a repetitive control gain matrix Ke and an output feedback gain matrix KP which enable the composite coefficient repetitive control system to meet the Lyapunov stability theory, and further obtaining the pre-off-line calibrated composite cooperative control law , ; Wherein, the In order to repeatedly control the gain matrix, In order to output the feedback gain matrix, The voltage control signal is output for the complex coefficient repetitive controller, Is the current component of the network-connected three-phase current of the grid side of the LCL type three-phase grid-connected inverter under an alpha beta coordinate system, Is the alpha-axis current component in the alpha beta coordinate system, Is the beta-axis current component in the alpha beta coordinate system, Is the final voltage control quantity.
7. The high-reliability complex coefficient repetitive control grid-connected inverter control system suitable for a power supply protection scene as set forth in claim 6, wherein the method for obtaining the alpha-axis voltage control amount and the beta-axis voltage control amount according to the composite cooperative control law, the alpha-axis current component, the beta-axis current component, the alpha-axis compensation voltage control amount of the current control period and the beta-axis compensation voltage control amount of the current control period obtained by offline calibration in advance comprises the following steps: Wherein, the As the voltage control quantity of the alpha-axis, Is the voltage control quantity of the beta axis, The voltage control quantity is compensated for the alpha-axis at the time t, The voltage control quantity is compensated for the beta axis at the time t, In order to repeatedly control the gain matrix, In order to output the feedback gain matrix, As a component of the alpha-axis current, Is the beta-axis current component.
8. The high-reliability complex-coefficient repetitive-control grid-connected inverter control system applied to a power conservation scene as set forth in claim 7, wherein the method for converting the alpha-axis voltage control quantity and the beta-axis voltage control quantity into three-phase modulation voltage signals through Clarke inverse transformation and generating the driving signals of the LCL-type three-phase grid-connected inverter through the three-phase modulation voltage signals and a space vector pulse width modulation method comprises the following steps: the α -axis voltage control amount and the β -axis voltage control amount are converted into three-phase modulation voltage signals by Clarke inverse transformation as follows: ; Wherein, the For the real-time alpha-axis voltage control quantity, For the real-time beta-axis voltage control quantity, For a phase a of the modulated voltage signal, For the b-phase modulated voltage signal, Modulating a voltage signal for phase c; SVPWM algorithm is adopted 、、 And converting the signal into six paths of PWM driving signals to drive the IGBT switch.
9. A high reliability complex coefficient repetitive control grid-connected inverter control method suitable for power conservation scene based on the system of claim 1, comprising: establishing a state space model representing the dynamic characteristics of the LCL type three-phase grid-connected inverter based on the topological structure and circuit parameters of the LCL type three-phase grid-connected inverter, and obtaining the grid-connected three-phase current of the grid side of the LCL type three-phase grid-connected inverter according to the state space model of the LCL type three-phase grid-connected inverter; converting the network-connected three-phase current into a current component under an alpha beta coordinate system through Clarke transformation to obtain an alpha-axis current component and a beta-axis current component, taking the difference between a preset alpha-axis reference current and the alpha-axis current component as an alpha-axis error current, and taking the difference between the preset beta-axis reference current and the beta-axis current component as a beta-axis error current; performing difference processing according to the alpha-axis error current and the beta-axis error current in the current control period and the alpha-axis compensation voltage control quantity and the beta-axis compensation voltage control quantity obtained by a complex coefficient filter in the previous current control period to obtain an intermediate alpha-axis compensation voltage control quantity and an intermediate beta-axis compensation voltage control quantity, and performing filtering processing on the intermediate alpha-axis compensation voltage control quantity and the intermediate beta-axis compensation voltage control quantity by using the complex coefficient filter to obtain the alpha-axis compensation voltage control quantity and the beta-axis compensation voltage control quantity in the current control period; obtaining an alpha-axis voltage control quantity and a beta-axis voltage control quantity according to a composite cooperative control law, an alpha-axis current component, a beta-axis current component, an alpha-axis compensation voltage control quantity of a current control period and a beta-axis compensation voltage control quantity of the current control period which are obtained through offline calibration in advance; the alpha-axis voltage control quantity and the beta-axis voltage control quantity are converted into three-phase modulation voltage signals through Clarke inverse transformation, and driving signals of the LCL type three-phase grid-connected inverter are generated through the three-phase modulation voltage signals and a space vector pulse width modulation method.
10. A computer program product comprising a computer program, characterized in that the computer program realizes the steps of the method as claimed in claim 9 when being executed by a processor.

Description

High-reliability complex coefficient repeated control grid-connected inverter control system and method suitable for power supply protection scene Technical Field The invention relates to the field of power electronic technology and new energy grid-connected control, in particular to a high-reliability complex coefficient repeated control grid-connected inverter control system and method suitable for a power supply protection scene. Background Solar energy and wind energy are used as emerging distributed power generation units, and compared with the traditional power generation industry, the solar energy and wind energy power generation unit has the problems of island effect, harmonic pollution and the like due to the limitations of the solar energy and wind energy. The harmonic pollution is a problem which needs to be solved by new energy power generation grid connection. The distortion of grid-connected voltage and current waveforms can cause electromagnetic interference to the along-way lines, and serious damage can be caused to safe and reliable operation of a power grid when serious. At present, a control strategy of the grid-connected inverter mainly comprises (1) PI control based on a dq coordinate system, park conversion and decoupling calculation are needed, model establishment is complex, (2) traditional repeated control, a real coefficient filter is adopted, coupling components under an alpha beta coordinate system cannot be effectively processed, and (3) proportional resonance control has good effect of inhibiting specific subharmonics, but multiple harmonics are difficult to inhibit simultaneously. The traditional repetitive controller adopts a low-pass filter, and ensures the stability of the system by sacrificing the high-frequency tracking performance. However, too large a bandwidth of the low-pass filter amplifies the measurement noise, and too small a bandwidth affects the harmonic suppression effect. In addition, the conventional repetitive controller is implemented in dq coordinate system or abc coordinate system, and requires complex coordinate transformation, which increases the computational burden. Disclosure of Invention The invention aims to provide a high-reliability complex coefficient repeated control grid-connected inverter control system and a method suitable for a power supply protection scene, which can simplify a grid-connected inverter control model, the harmonic suppression capability and the system robustness are improved, so that new challenges for the stable operation and power supply guarantee of the power system are presented by high-proportion new energy access. In order to achieve the purpose, the high-reliability complex coefficient repeated control grid-connected inverter control system suitable for the power supply protection scene comprises the following components: the state space model building module is used for building a state space model representing the dynamic characteristics of the LCL type three-phase grid-connected inverter based on the topological structure and circuit parameters of the LCL type three-phase grid-connected inverter, and obtaining the grid-connected three-phase current of the power grid side of the LCL type three-phase grid-connected inverter according to the state space model of the LCL type three-phase grid-connected inverter; the current error signal generation module is used for converting the network-connected three-phase current into a current component under an alpha beta coordinate system through Clarke transformation to obtain an alpha-axis current component and a beta-axis current component, taking the difference between a preset alpha-axis reference current and the alpha-axis current component as an alpha-axis error current, and taking the difference between the preset beta-axis reference current and the beta-axis current component as a beta-axis error current; the complex coefficient repetition control module is used for performing difference processing according to the alpha-axis error current and the beta-axis error current in the current control period and the alpha-axis compensation voltage control quantity and the beta-axis compensation voltage control quantity obtained by the complex coefficient filter in the previous current control period to obtain an intermediate state alpha-axis compensation voltage control quantity and an intermediate state beta-axis compensation voltage control quantity, and performing filtering processing on the intermediate state alpha-axis compensation voltage control quantity and the intermediate state beta-axis compensation voltage control quantity by using the complex coefficient filter to obtain the alpha-axis compensation voltage control quantity and the beta-axis compensation voltage control quantity in the current control period; The control voltage acquisition module is used for acquiring an alpha-axis voltage control quantity and a beta-axis voltage control quantity according to a c