Optimal Scheduling Strategy for Electric Vehicle Charging and Discharging Based on Two-layer Optimization Model

With the rapid promotion of new energy generation and electric vehicles around the world, the volatility and uncertainty of new energy and the randomness of electric vehicle charging have brought great challenges to the stable operation of the power grid. Therefore, this paper investigates the EV charging and discharging scheduling strategy and proposes an optimal EV charging and discharging scheduling strategy based on a two-layer optimization model. First, the reactive power interaction capabilities of distributed power sources and EV charging piles are analyzed. Second, a two-layer optimization model considering the reactive power response of bidirectional charging and discharging piles is established, with the upper layer aiming at minimizing the equivalent load mean square deviation and the lower layer aiming at minimizing the network loss, which are solved by the sparrow search algorithm and the second-order cone planning method, respectively. Finally, simulations are performed on the improved IEEE 33-node distribution network system for verification. The results show that the proposed scheduling strategy can effectively reduce the load peak-to-valley difference, decrease the network losses, and improve the voltage level of the system.