Modeling and Controller Design of Distribution Static Synchronous Compensator

Distribution static synchronous compensator (DSTATCOM) is an effective measure to maintain voltage stability and improve power quality of distribution grid. This paper deals with the modeling and nonlinear controller design of DSTATCOM. A nonlinear dynamic mathematical model of DSTATCOM is obtained by the switching function approach. A reactive-voltage decoupled PWM controller is designed based on multivariable inverse-system method. For the decoupled system, a control strategy combining control of state feedback and feedforward is employed, which can make the system have good transient response performance and anti-disturbing ability. By this method, the controller parameters´ design of both reactive current and dc-link voltage are simplified effectively. The theoretical analysis and design are verified by the simulation results.