Research On The Fuzzy Slide-Mode Variable Structure Control For Power System With Statcom

Static Synchronous Compensator(STATCOM) is a very important device of FACTS. The kernel equipment of STATCOM is power electronic converter. By injecting the smooth and rapid reactive current, it can maintain the bus voltage stability of the device in its setting point. Meanwhile it could also increase the system damping and improve the transient stability limit of power system. With the development of the power electronic manufacturing and the maturity of the FACTS, the enormous economic benefits and technical advantages of STATCOM have been widely recognized. In fact, STATCOM equipments have been installed in some practical projects.As more and more STATCOMs are connected into the grid, the issue of the interactions among the STATCOM and other devices existed in the power system has aroused great attention. The designing of a multi-objective coordinated controller has become a very important work.The power system requires a multi-objective control strategy to maintain its stability. Meanwhile, STATCOM has many control functions, which are helpful in enhancing the stability of the system. However, because of the conflicting among the different control objectives, it is hard to design a controller which could satisfy all the objective requirements. How to design a multi-objective controller becomes a very significant work.This paper combines the variable structure control method with the fuzzy control method to design a multi-objective controller in system level.In order to avoid the interactions, variable structure controller has been designed in this paper for coordinated the STATCOM and generator excitation device. Fuzzy control method is used here for reducing the chattering in a variable structure controller.A multi-objective controller based on the fuzzy control strategy is designed in this paper. The controller could determine the system state by the feedback signal and adjust the controller's parameters dynamically. In that way, the controller could find a compromised solution among the conflicting control objective to improve the dynamic character of the system.The simulation results in MATLAB verify that the control strategy proposed in this paper is effective.