Frequency control of a microgrid by using PI controller

Abstract

A power system stability is a very significant concern due to rapid increase in load demand and high level of living standard. Due to mismatch between generation capacity and load demand, fluctuation in power supply frequency and voltage oscillation comes in the picture. In the current scenario, renewable energy sources are one of the best options to mitigate the gap between energy demand and supply. A Microgrid is used to integrate renewable energy source with conventional grid. It can be use in connected or disconnected mode. In Microgrid structure, various micro sources come in picture like solar panels, wind turbine generator, battery storage system, flywheel storage system etc. In this case, the grid performing frequency is not equal to the required frequency. In order to reduce the frequency diversion and retaining the frequency balance between input and output, a controller is required which is smart, easily optimize to frequency change and also able to control the system in an easy way. In this paper, the controller is designed to dump out the frequency oscillations of power system by the use of a PI controller. The tuning is performed by both manually and Ziegler-Nicolas method and the optimize value of the controller parameters is calculated.