Control Strategy of Water Heater Group Based on Pre-switching State

Wind power accommodation has become the bottleneck of its further development, and the effective way to promote its accommodation is to match the wind power profile reversely by demand side resources. A novel demand response strategy for household electric water heaters is proposed in this paper. Firstly, the thermodynamic model and dynamic regulation model of water heater are established. The pre-switching state (PSST) is defined as the state in which the water heater will be turned on or off within 1 minute of normal operation. A grouping strategy considering PSST is adopted, and the priority of the water heaters in on and off groups is ranked based on the combined index of T_se and C_seto generate the priority sequence of the load group. Finally, the optimization model of load group power adjustment is proposed and applied to wind power accommodation. Compared with other strategies, the proposed one can track the wind power response target well, reduce the response error effectively and balance the heating effect of the load group. It has good application prospects.