Technology Of Statcom Based On Sliding Mode Control

As a kind of clean and efficient energy, electric is playing an increasingly important role in modern industry and life . Many countries invest a lot human and financial resources in smart grid in recent years, in order to promote the quality and safety of electric. Simultaneously, a plan of Strong and Smart Grid is being carried out in China. As a front technology and research hotspot in reactive power compensation,STATCOM (Static Synchronous Compensator) is one of the core equipments in smart grid.This paper mainly studies the control method of STATCOM. First, the STATCOM mathematical model is separately presented in abc static coordinate and dq rotating coordinate based on Kirchhoff's law. Second, verification of the models is given according to energy conservation law. Third, the underactuated property and non-minimum phase property of STATCOM is certified, which is a great help to the controll systerm designing. Then, STATCOM control structure is divided into voltage subsystems and current subsystems.STATCOM is a nonlinear system with strong coupling variables and sliding mode control can significantly enhance its disturbance rejection ability. By comparing sliding mode control and electronic systems, it's found that power electronic systems have a similar "chattering" phenomenon which means sliding mode control is suitable for such systems. Reaching law is a method that can effectively eliminate chattering. But there is much blindness for the initial parameters tuning because of no theoretical guidance. In this paper, classical PI control parameters tuning metherd is transplanted to reaching law parameters tuning. Through hardware in loop simulation experiments, the control strategy is verified with excellent performance.By dSPACE's capability of seamless connection to MATLAB, automatic code generation and on-line parameters tuning, the difficulty of controller designing is greatly reduced. Moreover, analysing the recorded experiments data helps to raise designer's level. The application of dSPACE in STATCOM control system is of some reference significance.