A Novel Controller for STATCOM to Enhance Power System Dynamic Behaviour

The paper presents a novel sliding mode controller (SMC) for STATic Synchronous Shunt Compensators (STATCOM) to enhance dynamic behaviour of a sample power system. The proposed controller consists of an equivalent control term, and a switching term. The controller employs deviation of STATCOM capacitor voltage from its reference value as input and the output is phase angle of the Voltage Source Inverter (VSI). The proposed controller adopts a control action proportional to the distance from the sliding surface. Steady state bifurcation diagrams are constructed for the test system and improvement of dynamic response by the proposed controller is illustrated in a bifurcation perspective through delaying the occurrence of Hopf bifurcation (HBF), saddle node bifurcation (SNB) and hence increasing the loadability limit.