Optimized voltage and frequency control in off-grid Power System

Abstract

This paper presents optimized control voltage and frequency of off-grid power system (OPS). The off-grid power system considered in this is having small isolated load supplied by power generation from of wind, PV and Diesel. wind energy converting system (WECS) consist of fixed speed squirrel cage Induction generator (SCIG), Photovoltaic system(PV) is connected through inverter. The other source in the OPS is diesel-genset equipped with governor and synchronous generator (SG) with automatic voltage regulator (AVR). Any variation load power causes frequency and voltage fluctuations. In this work,to regulate voltage through reactive power support, PV inverter is controlled and to regulate frequency the diesel power is controlled, through governor control. Hence, to coordinate control loops of voltage and frequency, are optimized simultaneously.The main contribution of this paper is to develop coordinated optimized control for voltage and frequency of OPS. Proportional integral (PI) controllers are used in the control loops are tuned optimally using on bacterial forging optimization algorithm(BFOA). OPS is simulated for step perturbation of load power (active and reactive) using developed coordinated optimized control.