Parametric Design And Application Of Robust Control For Power System

With the growing size and increasingly enhanced interconnection of modernpower system, higher and higher standard demands are made on security andstability of power system. In order to deal with the low frequent oscillation and thetransient stability issue, more and more attention is paid to new control method forpower system.The robust parametric approach provides the analytical form of thestabilization feedback control law which includes the closed-loop eigenvaluesdirectly. The parametric form not only can ensure the stability of the system, butalso can adjust the performance by selecting the poles or optimizing the poles in acertain region appropriately. In addition, the method provides extra free parameters,which are represented by the parametric vectors. The design of the stabilizationcontroller is transformed to optimize these free parameters. After an index is chosen,a mufti-objective optimization is realized on basis of the criterion to ensure theexpected performance.This paper proposes to utilize the robust parametric approach to power system.First of all, the superiority of this method is elaborated, and the adaptability isanalyzed in power system control. According to the situation of power system, theindex is improved for optimization and a proper range is given for the weightcoefficient.Then, the robust parametric method is applied to the power system excitationcontrol. The robust excitation controller is designed and numerical simulationresults show that the adaptive capability for the change of system structure isfavorable. It can gain better damping ratio and robustness. The parametric method isalso applied to the excitation and valve coordinated control. The robust valvecontroller and the robust excitation and valve coordinated controller is designed byusing parametric approach respectively. Numerical simulation results show that theperformance of the parametric valve controller and the parametric coordinatedcontroller has better robustness for the change of system structure and running state.It can also improve system transient stability. The robust parametric approach iseffective in single machine power system and multi machine power system.At last, in multi machine power system, a decentralized robust control strategyis proposed to improve the stability of the system. This paper provides a designmethod of interference rejection robust controller based on robust parametricapproach. The decentralized excitation controller and the decentralized excitationand valve coordinated controller realizes the decentralized coordinated control for multi machine power system. The simulation results show the effectiveness of therobust parametric approach.