College of Energy and Electrical Engineering, Hohai University, Nanjing 211100, China

Hydrogen energy can provide important support for the low-carbon transformation of China’s energy industry. The power-to-hydrogen technology can convert the renewable energy that is difficult to be accommodated by the power grid into green hydrogen and inject it into the natural gas pipelines, which enables the long-distance transmission and utilization of green hydrogen. This paper proposes an optimal dispatch model of the electricity-gas integrated energy system with green hydrogen injection, in which the grid auxiliary services are taken into account to accommodate high proportion of renewable energy. First, the quasi-dynamic operation model of the natural-gas system that considers green hydrogen injections and pipeline line-pack is established. Then, a flexible operation model of the integrated energy system considering auxiliary services of peak regulation and flexible reserve is constructed. Finally, numerical examples quantify and evaluate the value of power-to-hydrogen and multi-energy coordination on accommodating renewable energy and improving system operation flexibility. The impact mechanism of penetration ratio of renewable energy and ratio limit of pipeline injected hydrogen on dispatch results of integrated energy system is analyzed.