Modeling and power quality analysis of integrated renewable energy system

This paper presents modeling and power quality analysis of an integrated renewable energy system (RES) aimed at supplying electrical power to communities residing at remote locations, far from the grid supply. A decentralized power generation in the form of integrated system is proposed comprising of a solar photovoltaic (PV) system, a wind energy system (WES) and a micro hydro system (MHS) to supply required electric loads. The PV system is modeled with a dc-dc converter for regulating dc output voltage; a maximum power point tracking system (MPPT) is incorporated in order to achieve a reliable power output. The WES is modeled with a variable speed wind-turbine set with fixed pitch angle and the set drives a capacitor excited asynchronous generator (CAG). The CAG, in turn, is modeled with a closed loop turbine input system to account for the drooping characteristics of the asynchronous generator. The MHS consists of a constant power CAG. The three different sources are integrated and connected to a common ac bus and the performances of the system under varying loads are presented. A static synchronous compensator (STATCOM) is proposed in this work for reactive power compensation which, in turn, is expected to improve the power quality of the integrated system. The STATCOM is realized by means of a three-phase IGBT based current controlled voltage source inverter (CC-VSI) with a self-supporting dc bus. The complete system is modeled and simulated using Matlab/Simulink. The results obtained are presented and they are found to be satisfactory.