Development of coordinated control method based on Graph search method between EV and DG for voltage regulation

• Coordinated control between DGs and EVs addresses voltage problems in distribution systems. • Graph Search Method (GSM) optimizes reactive power control to resolve local voltage issues. • The proposed method enhances robustness to topology changes and reduces system losses. • Active power control is applied when reactive power alone cannot solve voltage problems. • OpenDSS and MATLAB integration verifies the performance of the proposed voltage control method. In this paper, a study is conducted to solve voltage problems that may occur, when large-scale Distributed Generations (DGs) and Electric Vehicles (EVs) are connected to the distribution system, through coordinated control between DGs and EVs. Using the Graph Search Method (GSM), the voltage problem was solved through the reactive power control of EVs and DGs in the near area where the voltage problem occurred. As a result, it was possible to obtain a result with high robustness against the change of the topology and reduction of the total loss of distribution system. In addition, when the voltage problem cannot be solved by only reactive power control, the active power control was performed for EVs and DGs included in a specific divided system of the conventional distribution system using the GSM to maintain the voltage within the normal range. Finally, to verify the performance of the proposed method, the whole algorithm was implemented by linking the Open Source Distribution System Simulator (OpenDSS), and the MATLAB.