State-space modelling of an interconnected system of renewable energy sources and grid for rural electrification

Abstract

This study deals with the development of a state-space model for an interconnected system of renewable energy sources (RES) with grid. The RES technologies considered for power generation in the interconnected system are doubly fed induction generator (DFIG) based wind energy conversion system and biogas genset. A linearised model for DFIG has been developed for the system. For biogas genset, the control of frequency and voltage is taken care by the electronic speed governor and IEEE type-I excitation system, respectively. The interconnected system takes a fixed feed of power supply from the grid and the rest of the consumer load is taken care by the RES. Finally, state feedback controllers have been developed for this interconnected system which maintains the active and reactive power balance between different sources of RES when small signal perturbations are given in load and input wind power. The comparative analysis has also been performed with the conventional PI controllers in order to demonstrate the superiority of proposed feedback controllers for the interconnected power system.