Realization of Robust Frequency Stability in Low-Inertia Islanded Microgrids With Optimized Virtual Inertia Control

Abstract

The increase in renewable energy resources penetration into microgrids weakens the inertia of microgrids and negatively affects their frequency stability. This reduction in inertia reduces the microgrid’s ability to handle disturbances and increases frequency instability risk. The purpose of this paper is to present a virtual inertia (VI) control strategy for an island microgrid with the use of an energy storage system (ESS) to improve inertia and frequency stability of the system. The VI controller parameters are optimized using the differential evolution (DE) algorithm. The proposed VI control strategy can effectively improve microgrid frequency stability and reduce the risk of frequency instability. The results demonstrate that the proposed strategy is effective and can provide fast and reliable virtual inertia support for the microgrid. The proposed VI control approach is verified through simulation results and performs better than the conventional inertial response for frequency stability in islanded microgrids. Virtual inertia control injects/absorbs active power into/from the microgrid during frequency deviations. Different disturbances are applied to demonstrate uncertain load and RES generation behavior. The proposed VI control method is compared with the available literature. In the proposed method, the frequency deviation is better controlled. Furthermore, the results demonstrate a more stable and efficient system operation with the developed VI controller than the existing methods.

Keywords

• Virtual inertia control
• differential evolution algorithm
• energy storage systems
• microgrid
• renewable energy resources