Hiroyuki Kaizu

New approach to the synthesis of a stabilizing control method for a power system

Abstract A new approach to the synthesis of a stabilizing control method for a multimachine power system is presented. The power system dynamics based on the usual assumptions can be formulated as a class of non-linear dynamic systems in which are contained the sinusoidal functions associated with the power torque-angle curve of the AC generator. In this theoretical scheme, an optimal control law, which retains the principal non-linearity of the system, is derived by using optimization techniques well known in linear optimal control theory. The stabilizing control of an N-synchronous machine power system with velocity governor and phase-shifter is synthesized by using the optimal control method. The usefulness of the proposed method is illustrated by the stabilizing control problem for a three-machine power system, taking into account additional control signals for the governing system and phase-shifter control systems, and simulation results are given numerically.

Synthesis of a stabilizing control problem for a multimachine power system with phase shifter

A systematic procedure is considered for the synthesis of a stabilizing control method for a multimachine power system with phase shifter, taking into account the velocity governor. A new approach is presented, which uses a coordinate-transformation technique and an optimization technique. The application of this method to a stabilizing control problem for a power system is illustrated by considering a 3-machine power system with phase-shifter control, taking into account an additional control vector for the governing system with one time constant. The synthesized controls are then used to improve the power-system transient stability to a remarkable degree and to restore the power-system transients rapidly to the stable-equilibrium point. Numerical results arc given.