Mitigation of Voltage Fluctuations in Grid-Connected Microgrids

Distributed renewable energy resources have variable active power output caused by changes in the environmental conditions, such as wind speed or solar irradiance, which affect the voltage magnitude in microgrids. Moreover, the load variations have an impact on the voltage magnitude. Such fluctuations have devastating effects, particularly on sensitive loads. Also, these fluctuations can cause flickering. In this paper, by using sensitivity analysis, the optimal reactive power of solar inverters is calculated and used to reduce the voltage fluctuations in solar photovoltaic-based microgrids. The proposed method leads to injecting or absorbing the reactive power to prevent the voltage fluctuations by solar inverters. This is done by sending data of changes of active and reactive power via a communication link. Therefore, the voltage magnitude of all buses is controlled without using any additional compensator. The proposed method is tested on the IEEE 33-bus distribution network. The results validate the efficiency of the proposed method.