Optimal Operation of Integrated Electricity-Gas Systems Considering Hydrogen Injection

This paper proposes an optimal operation method for integrated electricity-gas systems (IEGSs) considering hydrogen injection. First, the low-carbon operation mechanism (LCOM) is developed incorporating carbon capture, power-to-gas and hydrogen enriched compressed natural gas (HCNG) technologies. Second, a united HCNG energy flow model is proposed, including the modellings of pipeline flow, compressors, gas-fired units, and nodal gas flow balance, in which the strong coupling relationship between hydrogen volume fraction and HCNG energy flow model is captured. Then, a low-carbon dispatch model for IEGSs is developed based on the proposed LCOM and HCNG energy flow model, which minimizes the system operation cost while maintaining both gas pressure and HCNG flow rate within acceptable ranges. Furthermore, the model linearization methodology incorporating the piecewise linearization method and Taylor expansion are developed, which reformulates the dispatch model as a tractable mixed-integer linear programming problem. Finally, the effectiveness of the proposed model and method are verified in case studies.