Robust PI Controller for Frequency Stabilisation of Islanded Microgrid Operation using Battery Energy Storage System

Abstract

Background/Objectives: Maintaining constant frequency in an Islanded microgrid is highly demanding and challenging issue. Therefore it is proposed to use Robust PI Controller for controlling the frequency of islanded microgrid using Energy Storage system. Methods/Statistical Analysis: The proposed Robust PI controller provides the required frequency stability to the islanded microgrid. The test modeled in MATLAB Simulink environment. The Test system modeled as typical remote location (Island or Military Power Grid or Geographically Disconnected or Hilly Terrain) with a wind turbine and Solar panel, along with distributed loads and Energy storage system. Findings: The drawbacks of the traditional PI controller to adapt to the parametric variations and to provide faster response is overcome using proposed Robust PI controller. The inherent disadvantage of PID controller such as instability and peak overshoot is also overcome with the proposed controller. The Proposed Robust PI controller provides the improved dynamic frequency stability and reduced peak overshoot to the islanded microgrid with in 0.3seconds, if the microgrid is suddenly disconnected from the main grid. The controller also tested under various conditions and it provides required frequency stability to test system during islanding operation. The proposed method is simple, flexible and provides improved performance as compared to the existing methods and approaches for frequency stability of islanded microgrid. Application/Improvements: The proposed controller can be used in remote location and provides simple, yet cost effective solution as compared to costlier PID Controller based on fuzzy logic and neural network.