Simulation And Research Of STATCOM In A Distribution System

As electric power systems grow and become more interconnected, high voltage transmission network is founded and the request of reactive power is more strict. Reactive power source is an indispensable part of improving power quality, reducing net loss and keeping system stable. Reactive power imbalance will result in a voltage sag and the damage of electro-equipment. Var compensation is important to power system, so the related research is significant.STATCOM (Static synchronous compensation) is a new kind of Var compensation installment. STATCOM is a voltage source inverter connected to the system by transformer or reactor, dynamic reactive power compensation is achieved by regulating phase and amplitude of the voltage or the current injected into power system.In this paper, the system structure and work principle of STATCOM are introduced. The dynamic math model of STATCOM is established, the stability of STATCOM is proved by Routh-Hurwitz criterion.Cascade multilevel inverter is adopted to enhance voltage level, capacity and eliminate harmonics. Detection technology based on instantaneous reactive power theory is studied.The simulating model of distribution system of TPCO (Tianjin Pipe Corporation) is built up. The indirect reactive current control is studied, not only can inhibit the system voltage sag, but can maintain DC voltage. In this paper, STATCOM is applied in the distribution system of TPCO. The system with STATCOM is simulated by MATLAB, so the ability of STATCOM to support voltage is proved. The effect of different parameters of STATCOM on the voltage of capacitor is analyzed in theory and simulation. Simulation results shows that the ability of STATCOM to support voltage is more competent than SVC .