Controller Design for Hybrid AC/DC Microgrid System with Renewable Sources and Motor Loads

Abstract

The present trends in power system is gradually shifting towards the vision of smart grids. Here, the present distribution system is moving from being passive to active in nature because of increasing penetration of Renewable Energy Sources (RESs). This is resulting into formation of microgrids (MGs) having its own sources and loads. Now, the grid connected and islanded mode are operated in MGs. The working of MGs in presence of motor loads is very crucial control problem due to low inertia in the RESs. This paper introduces the integrated ac/dc MG that are applicable in a real-time controller design, which include renewable energy conservation and motor loads. When the hybrid microgrid is separated from the utility grid, it is works in special mode for acceptance of intermittent generation of the RESs. This calls for storage of the energy to provide good quality power supply to the loads especially the motor loads. It proposes the power flow control of the ac/dc hybrid MG with the help of converters which are of bidirectional nature. An AC/DC dual-powered converter is capable of cutting off active and passive power which are connected to ac to dc bus and it controls the frequency of the MG system and power flow. The output from generator is connected to the solar by the function of maximum power point tacking which is high by using a DC/DC booster converter. The battery banks that are attached to store the energy and increases the stability of the system. Because of low inertial characteristics of power electronic converters, the working of motor load is emphasized. The test results are presented to confirm the proposed AC/DC hybrid MG control scheme.