Study of Integrated Rural Electrification System Using Wind-Biogas Based Hybrid System and Limited Grid Supply System

Abstract

This paper presents modeling of system having wind-biogas based hybrid system operating in parallel with limited grid supply system to meet the rural demand, of a cluster of villages continuously. In this integrated rural electrification system (IRES), a fixed part of the power is supplied by the grid and the remaining power, required by the load under steady state and also the variations, is taken care by a hybrid renewable energy system (HRES). The wind energy converting system (WECS) uses a permanent magnet synchronous generator (PMSG) and synchronized in the hybrid system through a voltage source converter (VSC). The other source considered in the hybrid system is biogas-genset equipped with electronic speed governor and synchronous generator (SG) with automatic voltage regulator (AVR). The variation in load and/or input wind power to WECS may cause deviation in frequency and voltage and to maintain these parameters at nominal values, the power generated by biogas-genset is controlled, through governor control. The basic control schemes for frequency and magnitude of system voltage may not ensure limited grid operation. Therefore the system model is unique as it considers the dynamics and control of system voltage angle also. The main contribution of this paper is the system dynamic model development and its performance study. Proportional integral (PI) controllers are used in the model and their values are optimized using integral square error (ISE) criteria. Finally, the system simulation results have been shown for step deviations in load and/or input wind power to the WECS.