Seamless Transfer of Renewable-Based Microgrid Between Utility Grid and Diesel Generator

Abstract

This paper deals with the renewable energy-based microgrid (MG) to feed the community loads. It has the capability to synchronize with the utility as well as with the diesel generator (DG) set. During healthy grid condition at high renewable power generation and when load demand is less, it feeds power to the grid while at low renewable generation power is taken from the grid. During outage and low renewable power generation, it synchronizes with the DG set to meet the load demand and forms a hybrid microgrid. In islanding, the voltage source converter (VSC) operates in a voltage control mode for realizing a renewable MG and operates in the current control mode for implementing a hybrid MG and switching to the grid-connected mode. An incremental conductance and perturb & observe approaches with a boost converter are implemented for the maximum power extraction of the renewables. A battery bank is connected at the dc link of VSC. The multifunctional MG synchronization and de-synchronization with ac mains/DG set are discussed in conjunction with variety of test results. In this topology, a single bidirectional converter is implemented and controlled using various control algorithms to manage MG power among generation, storage, and load units. A MATLAB/Simulink model is developed for a wind–solar–diesel based MG. Simulated results are validated with test results on a developed laboratory prototype.