A Novel Controller for Inverters to Improve the Frequency Response of Micro Grid under Transient Conditions

Abstract: The present scenario is towards shifting centralised power generation (central grid) to distributed generation (micro grid) with smaller sources of capacity. The isolated micro grid is connected to main grid with inverters at the front end for efficient exchange of power sharing; power exchange among distributed generation (DG) sources in an isolated micro grid is possible with droop characteristics as per their capacity. The stability and operation aspects of converter-dominated microgrids (MGs), however, are faced by many challenges. Important among these, are the absence of physical inertia, comparable size of power converters, mutual interactions among generators islanding detection delays and large sudden disturbances associated with transition to islanded mode, grid restoration, and load power changes. Sources in the MGs use droop control to share power according to their capacity without any form of communication. This paper proposes a novel controller for inverters in DG for improving transient frequency response of the micro grid under consideration of large disturbances with considerable frequency deviations to validate the effectiveness of the proposed P-F droop controller simulation is carried out on MATLAB Simulink platform.

Keywords: DG (Distributed Generator), MATLAB SIMULINK, Transient Frequency Responses, Droop Characteristics, P-F Control.