Coordinated scheduling of flexibility sources in an air-conditioning system with chilled water storage under dynamic electricity pricing

Under dynamic electricity pricing with high renewable penetration, a key issue in demand-side management is how to convert building loads into high-quality flexibility while limiting indoor-temperature variation. Existing dual-source coordination studies mostly remain within sequential or fixed-ratio shared-use modes, while dynamic ratio handover beyond such modes still lacks systematic discussion and experimental validation. To address this, this study proposes a staged coordination framework for the coordinated use of chilled water storage and building thermal mass, centered on a lead–relay–handover logic. Based on an experimental air-conditioning system with chilled water storage, single-source dynamic regulation tests, dual-source coordinated regulation tests, and all-day tracking tests under three representative dynamic electricity price structures are conducted. By quantifying response time, power ramp rate, load-adjustment magnitude, indoor-temperature variation, and operating cost, the regulation performance of different strategies and lead–relay sequences is compared. The results show that chilled water storage-led provides faster response and larger adjustment, while building-led operation is smoother and provides better indoor-temperature stability. The proposed method enables a flexible trade-off among response strength, indoor-temperature stability, and energy quality. For the Hunan and Fujian price structures, the calculated all-day operating cost is reduced by 13.7% and 14.5%, respectively, under the selected baseline and tariff conditions on the platform. Under the Beijing low-frequency single-peak price structure, the proposed strategy achieves effective price tracking and load reshaping. This study provides a reusable coordination method for flexible control of air-conditioning systems with chilled water storage under dynamic electricity pricing.