The Research Of Synchronous Generator Excitation Control Based On Modern Interior Point Nonlinear Programming

It is very important to improve and enhance the stability of the power system for the national economics. The technical method that improves power system stability is control. It is difficult to find the optimal control law for nonlinear system such as the power system. Such the wider application nonlinear control based on the differential geometry method, which can only derive the optimal control law for the exact linearized system, and this method cannot guarantee to derive the optimal control law for the nonlinear system. It is noteworthy that solving the nonlinear system with nonlinear programming method, which can find the optimal result. Therefore, using the nonlinear programming method can find the optimal control law for the nonlinear system under the performance index.This paper proposes a novel scheme for the nonlinear control design based on modern interior point nonlinear programming method. The quadratic performance index of control system is chosen as the objective function of nonlinear programming; all state equations of control system will be converted into numerical equivalent algebraic equations set by using the implicit trapezoidal rule, and are involved in equality constrains set; all control quantity limits are used to be inequality constrains. The optimal control problem is transformed into nonlinear programming problem, and then the nonlinear control design idea based on programming method is acquired. It implies that the necessary conditions of the optimal control are equivalent to the Karush-Kuhn-Tucker conditions of nonlinear programming. Modern interior point nonlinear programming method is applied to solve the nonlinear programming problem.For the generator excitation control system, a nonlinear excitation control design method is derived based on modem interior point nonlinear programming. The results of simulation show that the scheme can coordinate the dynamic and the static performances of the synchronous generator effectively, and make it have a good output performance.