Online Power Quality Assessment of Microgrid with EVs in Vehicle-to-Grid Configuration

With technological advancements, the new era of clean and efficient transportation brings significant social and technical difficulties to the modern electric grid. Increasing the demand on the charging infrastructure can strain the electrical grid and have a detrimental impact on other customers that are linked to it. Instead of being a further electrical load, the batteries of electric vehicle (EV) are also used as an energy storage (Vehicle-To-Grid, V2G). However, there is a need to assess the grid quality because of this V2G configuration. To this end, an online power quality (PQ) monitoring approach at microgrid is presented in this paper with the simultaneous fast discharging of four EVs. The proposed methodology uses the S-Transform for online PQ assessment. The simulated off-board EV station ensures that the grid injected current has the least harmonic distortion possible, and the controller delivers good dynamic performance in regard to dc bus voltage stability. After accurate identification of PQ issues, this study will further be helpful in PQ improvement by installing appropriate PQ mitigation devices.