Delaying instability and voltage collapse in power systems using SVCs with washout filter-aided feedback

This paper introduces washout filter-aided feedback in the design of static var compensator (SVC) control to increase the range of stable operation of a power system susceptible to voltage collapse. The use of such a control automatically maintains the open-loop steady state operating conditions. In contrast to static state feedback designs, washout-filter based designs are more efficient because no control energy is spent on needlessly maintaining an unintentionally shifted system equilibrium. The control design is illustrated in a sample power system model that undergoes a Hopf bifurcation and voltage collapse as the reactive power demand is increased to a critical value. It is seen that the control meets the goals of delaying (or eliminating) the Hopf bifurcation while at the same time maintaining the open-loop operating condition.