Low-Carbon Economic Dispatch of Electric-Thermal-Hydrogen Integrated Energy System Based on Carbon Emission Flow Tracking and Step-Wise Carbon Price

To address the issues of unclear carbon responsibility attribution, insufficient renewable energy absorption, and simplistic carbon trading mechanisms in integrated energy systems, this paper proposes an electric-heat-hydrogen integrated energy system (EHH-IES) optimal scheduling model considering carbon emission stream (CES) and wind-solar accommodation. First, the CES theory is introduced to quantify the carbon emission intensity of each energy conversion device and transmission branch by defining carbon emission rate, branch carbon intensity, and node carbon potential, realizing accurate tracking of carbon flow in the process of multi-energy coupling. Second, a stepped carbon pricing mechanism is established to dynamically adjust carbon trading costs based on the deviation between actual carbon emissions and initial quotas, strengthening the emission reduction incentive. Finally, a low-carbon economic dispatch model is constructed with the objectives of minimizing operation cost, carbon trading cost, wind-solar curtailment penalty cost, and energy loss. Simulation results show that compared with the traditional economic dispatch scheme 3, the proposed scheme1 reduces carbon emissions by 53.97% and wind-solar curtailment by 68.89% with a 16.10% increase in total cost. This verifies that the model can effectively improve clean energy utilization and reduce carbon emissions, achieving low-carbon economic operation of EHH-IES, with CES theory ensuring precise carbon flow tracking across multi-energy links.