Secondary voltage control: analysis, solutions and simulation results for the Spanish transmission system

Secondary voltage control (SVC) was introduced in some European countries as a means to improve power system voltage security and operation. It is a closed loop system dedicated to keep the voltages of some load buses, called pilot buses, constant. In this paper, a new approach covering all the main aspects of SVC-pilot buses and control generators selection; the control law; and the decentralization problem-is presented. This approach has been applied to the Spanish power system. Some of the results obtained are also presented