A two-level optimal scheduling control strategy for air source heat pump loads with phase change energy storage

Abstract

Reasonable scheduling and control of air-source heat pumps (ASHPs) contribute to reducing operational costs for users while encouraging their participation in grid demand response. This article proposes a two-layer optimal scheduling and control strategy for ASHP loads incorporating phase change energy storage (PCES). First, an electricity-heat coupling model for ASHP loads is proposed. This model integrates PCES technology and considers the influence of outlet water temperature, ambient temperature, and the cold island effect on the coefficient of performance. Subsequently, a PCES capacity configuration model is established with the objective of maximizing the overall benefits of the PCES device. Finally, a two-layer optimal scheduling and control strategy for ASHPs is introduced: The upper-layer model employs model predictive control to minimize heating costs based on user comfort, leveraging PCES and building thermal storage characteristics, in conjunction with time-of-use electricity pricing. The lower-layer model schedules periodic start–stop cycles of the ASHP units to respond to the upper-layer power demand and mitigates the impact of the cold island effect on ASHP performance through unit interval sequencing. The simulation results show that the proposed strategy reduces the daily operation cost and power consumption by 38.9% and 25.0%, respectively, significantly improving the building's regulation capability.