An analytical review of power-system frequency, time and tie-line control

Over the past decade and a half there have been proposed three schemes of control for electricity supply systems interconnected through tie lines. In chronological order they are the speed-governed system with frequency biasing, the time-governed system and the load-phase energy control. The paper describes computer studies which compare the three systems using a performance index of the integral square error. Certain conclusions are drawn by applying this criterion both to the frequency error of the isolated system and to the tie power-flow error of the interconnected system.