Multi-timescale scheduling and active-reactive support study of electric vehicle resources for hierarchical urban grids

As the penetration rate of new energy continues to increase, distribution networks face multiple challenges such as voltage fluctuations and frequency stability. As widely distributed controllable loads and energy storage resources, electric vehicles (EVs) have the potential to participate in grid regulation and auxiliary services based on their bidirectional power flow capability. In this paper, an active/reactive decoupling model of EV inverter based on PI control is firstly established, and a PQ capability constraint model is constructed by combining the apparent power and battery boundary conditions. On this basis, a Q-U response mechanism based on sag control and a P-f frequency support strategy are designed to realize the fast dynamic response of EV to grid disturbances. A cooperative reactive power optimization strategy oriented to minimize the voltage deviation of regional nodes is further proposed to realize distributed coordinated control in combination with consistency control. Finally, a multilevel control architecture is constructed to integrate the main grid-level scheduling, distribution-level coordination, and microgrid-level fast response to improve the real-time and robustness of control.