Deep reinforcement learning-based strategy for charging station participating in demand response

The trend of zero-carbonization has accelerated the prevalence of electric vehicles (EVs) owing to their advantages of low carbon emissions and high energy efficiency. The stochastic and high charging load of EVs results in a non-negligible challenge that may cause grid overload. A promising approach is the participation of charging stations in demand response as load aggregators by coordinating the charging power of electric vehicles. However, improper coordination of charging load may lead to unfulfilled charging demand, which would cause dissatisfaction on the demand side. In this study, the incentive-based and time-varying demand response mechanism is considered when charging stations coordinate charging of multiple EVs. A decentralized decision-making framework is innovatively applied to provide charging power of each EV. The charging process is modeled as a Markov decision process, and a virtual price is designed to help decide the charging power. Deep reinforcement learning algorithms such as deep deterministic policy gradient are applied to determine the charging strategy of multiple and heterogeneous EVs. Numerical experiments are performed to validate the effectiveness of the proposed method. A comparison with an optimal charging strategy and a heuristic rule-based method shows that the proposed method can trade off the revenue from demand response and user satisfaction, as well as reduce the peak load of the charging station. Furthermore, a test with inaccurate departure information indicates the robustness of the proposed method.