Closed Loop Optimization of Power Systems with Two-Axis Excitation Control

This paper describes the results of studies made to improve the dynamic response and damping torques of power systems incorporating synchronous machines with 2-axis excitation control. Dynamic optimization techniques have been used to determine the optimum controls subject to a quadratic integral performance index. The system has been simulated as a seventh order, closed loop, non-linear model incorporating speed governor and voltage and angle regulators. Modified quasilinearization and first order gradient methods have been utilized for solving the optimization problems for this non-linear system. The investigations indicate that optimal control of doubly excited synchronous machines is possible and that it yield, s improved transient performance. Incidentally, some possible limitations of the quasilinearization technique have also been brought out.