The electricity-hydrogen coupling system is an important way to promote the low-carbon transformation of energy structure. However, the supply and demand of electricity and hydrogen are the inverse distribution of time and space, which seriously restricts the low-carbon economic development of electricity-hydrogen coupling systems. The existing dispatching methods of cross-region electricity-hydrogen coupling systems have some problems, such as low utilization rate of new energy and high operating cost. Therefore, an electricity-hydrogen coupled system dispatching method considering the coordinated inter-region transportation of electricity and methanol is proposed in this paper. The supply and demand balance of regional electricity and hydrogen can be better through the coordinated inter-region transportation of electricity and methanol, so as to improve the inter-regional economic consumption level of new energy and the system operation economy. First, based on the energy supply and demand characteristics of the sending and receiving areas, the operating characteristics of the electricity/hydrogen subsystems and the transport characteristics of methanol, the cross-regional cooperative operation mechanism and the dispatching framework of the electricity-hydrogen coupled systems are designed. Secondly, the supply and demand balance model is developed considering the coordinated inter-region transportation of electricity and methanol, so as to ensure regional energy demand under multi-time scales. Finally, a bi-level dispatching model of electricity-hydrogen coupling system is established under the electricity-methanol inter-region cooperative transport. The upper-level model determines the daily methanol transportation plan and unit commitment plan. The lower-level model is developed to determine the annual time series operation plan of the transmission and receiving zone. The characteristics of energy production and demand in the sending and receiving areas and the flexible transfer of time and space are fully considered in the bi-level dispatching model. In this way, the safe and economical operation of the cross-region electricity-hydrogen coupling systems can be realized under multi-energy coordination and multi-channel coordination. The improved HRP 38 is used to test the proposed method. The simulation results indicate that compared with the existing operation dispatching methods of the cross-region electricity-hydrogen coupling systems under single energy transmission channel and electricity-hydrogen long-tube trailer transport, the operation dispatching method of the electricity-hydrogen coupling system using electricity-methanol inter-region collaborative transport can significantly improve the operation economy and new energy consumption of the system. Compared with a single energy transmission channel, electricity-methanol inter-regional collaborative transport expands the consumption channel of new energy. Through the reaction of hydrogen production and methanol synthesis in electrolytic cells, the surplus new energy can be converted into methanol, which can be transported to the receiving region through the transportation system, thus realizing the multi-channel inter-regional consumption of new energy. Compared with the energy transport only using methanol or electricity energy, this synergistic transport has increased energy consumption by 33 883 GW·h and 3 264 GW·h, respectively. Compared with electricity and long-tube trailer inter-region transport, electricity-methanol inter-regional collaborative transport takes advantage of methanol economic storage and transportation, reducing the system energy inter-region transport cost and system operation cost by 10.69%. At the same time, the simulation results of different hydrogen load permeability show that when the hydrogen load increases to a certain extent, in order to reduce the dependence on high purchased hydrogen, hydrogen production facilities in the system need to be expanded to ensure the economic operation of the system. The following conclusions can be drawn from the simulation analyses in the paper. (1) Considering the supply and demand characteristics of the sending and receiving regions, the utilization of electricity-methanol collaborative transport to optimize the scheduling of the cross-region electricity-hydrogen coupling system can promote the cross-region consumption of new energy and improve the level of low-carbon economic operation of the system. (2) Methanol has significant economic advantages in long-distance energy storage and transportation, which can realize the transfer and optimal utilization of new energy across time and space. (3) With the increase of hydrogen load permeability, the dependence of the hydrogen energy supply of the system on externally purchased hydrogen is gradually enhanced. It is necessary to timely increase the methanol transport capacity and the capacity of hydrogen production, storage and use equipment in accordance with the increase of hydrogen load. © 2024 China Machine Press. All rights reserved.
