Research On Power Decoupling Control Strategy Of Micro-grid Based On Inverse Decoupling Auto-disturbance Rejection Control

In recent years,due to the rapid development of new power electronics technology,a large number of renewable energy distributed power generation units have been integrated into power generation systems.In order to better integrate the problems between distributed generation and large power grid,the microgrid system consists of multiple distributed units to provide efficient and reliable energy for the load.The flexibility and reliability of microgrid operation depend on good control methods.Because the line parameters of microgrid are resistive or resistive,they do not meet the application conditions of traditional power control,and the output power of distributed power supply has coupling phenomenon.It is difficult to achieve accurate power allocation,which affects the stability of the system.This paper focuses on the power decoupling control strategy in microgrid operation.Firstly,the generation and development of distributed power generation technology is analyzed,and then the background,significance and current situation of the generation of micro-power grid are analyzed.Four traditional inverter control methods are described: PQ control,V/ f control,traditional P-f,Q-V droop control and droop P-V,Q-f control.A three-phase inverter model is established and a voltage-current double-loop controller and a filter are designed.Secondly,the inverse decoupling control strategy based on relative gain analysis is proposed to solve the power coupling problem of microgrid.The method of relative gain analysis is applied to the matching selection of the power model of the microgrid line,and the coupling degree of the control channel is quantized.According to the known model information,the inverse decoupling control link is designed,and the control coupling channel is eliminated.The diagonalization of the generalized object is realized and the power coupling problem in the operation process of the microgrid is solved.Then,considering that the equivalent impedance of transmission line in microgrid is difficult to obtain due to the local load,this paper analyzes a method to detect the parameter impedance ratio of transmission line.The transmission line parameters of microgrid are detected and the accuracy of this method is verified by simulation.Finally,based on inverse decoupling control,this paper proposes a power decoupling control method of microgrid based on inverse decoupled ADRC control by adding auto-disturbance rejection control(ADRC)to the inverse decoupling control(ADRC).The extended state observer in the ADRC can estimate and compensate the disturbance information in real time,which enhances the tracking and anti-disturbance of the system set value,overcomes the residual adjustment,eliminates the disturbance quickly,and improves the control performance of the system.The simulation model of micro-grid control system is built in Matlab/Simulink environment.The simulation results of traditional power control strategy,inverse decoupled PI control strategy and inverse decoupled auto-disturbance rejection control strategy are carried out to verify the effectiveness of the proposed scheme.