Multi-time scale coordinated dispatch of integrated electricity-hydrogen-heat microgrids with waste heat recovery

• An integrated electricity-heat-hydrogen microgrid architecture with cascaded waste heat recovery is developed. • A unified model for the full hydrogen chain and waste heat utilization dynamics is established. • A multi-time scale dispatch strategy coordinating day-ahead, intra-day, and real-time is proposed. • The low-carbon benefits of the system are quantified by using a carbon emission flow model. Hydrogen energy plays a crucial role in integrating renewable, reducing carbon emissions, and boosting the operational flexibility of multi-energy microgrids (MEMG), owing to its substantial storage capacity and clean characteristics. However, a key challenge arises in the coordinated dynamic dispatch between power flows and the multi-stage hydrogen value chain, which includes production, conversion, utilization, and waste heat recovery. To address this, we introduce a novel multi-time scale operational framework for MEMG that considers electricity-hydrogen coupling and encompass the entire hydrogen process chain. This framework operates on a three-phase model: day-ahead scheduling aimed at minimizing daily operating costs; intraday rolling optimization every 15 min to adjust for renewable energy fluctuations; and real-time adjustments to fine-tune key conversion devices. Additionally, a carbon emission flow is integrated into the day-ahead phase to guide the dispatch of hydrogen and electricity towards low-carbon operations. Case studies demonstrate that our proposed framework lowers total operating costs by 6.64% and cuts carbon emissions by 13.06% compared to traditional day-ahead scheduling. This work offers a practical, system-level operational strategy to enhance both the economic and environmental performance of future flexible energy systems.