QFT DESIGN FOR LOAD FREQUENCY CONTROL OF WIND DIESEL SYSTEM USING CES

Abstract

In an isolated wind-diesel system, the variable power consumptions as well as the intermittent wind power may cause a large fluctuation of system frequency. If the system frequency cannot be controlled and kept in the acceptable range, the system may lose stability. Further to reduce system frequency fluctuation, CES which is able to supply and absorb active power quickly, can be applied. In addition, variation of system parameters, unpredictable power demands and fluctuating wind power etc., cause various uncertainties in the system. A CES controller which is designed without considering such uncertainties may lose control effect. In this paper quantitative feedback theory method is used for LFC control problem in Wind-Diesel system with system parametric uncertainties like parameter variations ±25% from their nominal value, ±30% load variations and wind variations. To show effectiveness of proposed method, a classical PI controller is designed for LFC for comparison with QFT.