Optimal Energy Management of DC Microgrid System using Dynamic Programming

Abstract

Abstract Because voltage regulation of direct current(DC) microgrid is controlled by active power, it is closely related to optimal energy management. In a conventional DC microgrid, the microgrid scheduling is defined as the optimization problem considering the cost of power sources, demand response(DR) and electric vehicle(EV) that make up the system. In this case, the voltage stability is considered separately in power flow analysis. However, since the voltage control is related to economy, it is reasonable to consider it together with the optimal scheduling problem. Considering both the voltage control and the optimal management problem has the issue of increasing the complexity. Hence, this paper proposes optimal operation strategy using dynamic programming(DP) in DC microgrid system to reduce the complexity of the problem. This study is a preliminary study to consider voltage control and economics, and it uses DP to define a day-ahead optimal scheduling problem. The proposed method is verified by DC microgrid system configured by using MATLAB. The result of optimal energy management shows that the proposed strategy reduces complexity and makes reasonable results.