Application Of Improved Fuzzy Control Algorithm In STATCOM

Since the 21 st century,industrial production and humans’ lives demand for electricity increasingly,the power quality put forward higher requirements.A lot of reactive power flow in the power grid,it affects the safe operation of the power grid.With the rapid development of power electronics technology,power electronic devices are gradually applied in reactive power compensation field.STATCOM is one of the hotspots in flexible AC transmission systems.Experts and scholars at home and abroad have spent much time and energy improving STATCOM technology level,increasing the compensation capacity of STATCOM,speeding up the response speed and improving the compensation effect.STATCOM is deeply studied in this paper.The main circuit structure of STATCOM is voltage-type bridge circuit.As the accuracy of current detection directly affects the accuracy of compensation of reactive power,and affects the compensation effect,thus the current Feed-forward decoupling control is designed to detect current.Comparing to id-iq detection method,the current Feed-forward decoupling control realizes the decoupled control of d-axis and q-axis currents.It can improve detection accuracy.The control algorithm directly determines the compensation effect of STATCOM.This paper designs a dual fuzzy PI control algorithm which is based on the fuzzy control algorithm and the current Feed-forward decoupling control,The current Feed-forward decoupling control eliminates the coupling between d-axis and q-axis currents,and forms a double-closed-loop system,and combines the advantages of fuzzy PI control algorithm to design a dual fuzzy PI controller.In order to verify that the dual fuzzy PI control algorithm can stabilize the grid voltage level and improve the quality of power supply,this paper builds system simulation models which are based on the fuzzy control algorithm,PI control algorithm and dual fuzzy PI control algorithm respectively in the MATLAB/Simulink simulation environment.In addition to different control algorithms,the simulation model and the parameters of the three systems are the same.The comparison of the three simulation results verifies the superiority of dual fuzzy PI control algorithm.