Control algorithms for shunt VAR systems

Experimental investigations of shunt VAR systems (SVSs) on a model machine network illustrate the desirability of changes in the control system of the SVS as the operating conditions of the network vary. The fast time constant and the increase of stabilizing effectiveness at high load angles both favour the use of SVSs in damping of power system oscillations. As with AVRs, the control algorithms to give good damping must use signals other than voltage error. Experiments demonstrated that power swing damping can be obtained using a power signal in a micro-processor implemented feedback control system.