Robust stabilization of a power system based on direct control of generator power by a series variable impedance unit

Power system stabilizing controllers have become more and more intelligent with the advancement of technologies in power electronics devices and circuit topologies. However, nonlinearities that are inherent in power system dynamics often spoil the robustness of a power system controller designed at an operating point. In this paper we propose a power system stabilizing controller using a variable series impedance unit with a control reference to obtain the prespecified linearized power swing characteristics. It is expected that the control scheme will be robust in the sense that the control parameters do not have to be readjusted even if the configuration or the operating point of the power system is changed. Some numerical studies demonstrate the significant effect of the proposed controller, in which a variable series impedance is used, on the power system stabilization. © 1998 Scripta Technica, Electr Eng Jpn, 123(4): 34–40, 1998