VOLTAGE AND FREQUENCY REGULATION WITH SYNCHRONIZATION OF MICRO GRID UNDER ISLANDING OPERATION

Abstract

The day-by-day increasing demand for energy can create problems for the power distributors, like grid instability and even outages. The necessity of producing more energy combined with the interest in clean technologies yields in an increased development of power distribution systems using renewable energy. In this purview, several types of Distributed Generations (DGs), local loads, storage system and voltage source converter can be connected together to form a small local power generation system called as micro grid (MG). MG can operate in grid connected mode or in islanding mode. The paper discusses islanding control of power electronics interfaced with DG systems in micro grid. Further, a new topology is introduced with zig-zag/star transformer, which reduces the size of battery connected parallel to DC link of the voltage source converter, hence reducing the cost of the system. The proposed topology works well in maintaining phase angle, voltage and frequency of the micro sources in islanded mode as well as in resynchronization when one of the micro sources is off due to fault or unavailability of resources. The proposed topology is verified in MATLAB environment.