Day-Ahead Energy Trading Strategy of Regional Integrated Energy System Considering Energy Cascade Utilization

The traditional energy system has the disadvantages of high energy consumption and high emission. Through multiple energy networks interconnection and flexible energy conversion, the regional integrated energy system (RIES) can satisfy various energy demands and achieve clean and efficient energy utilization. However, the demand and supply relationship of RIES is complex. Without a reasonable energy supply structure, it’s difficult for RIES to give full play to the economic and efficient operation. At the same time, the multi-energy trading and service mechanisms are still unclear. The promotion of RIES brings challenges and opportunities to energy sector. In order to address the issues in the promotion of RIES, a day-ahead energy trading strategy of RIES considering energy cascade utilization is proposed in this paper. Firstly, the relationship between energy suppliers (ESs), integrated energy service provider (IESP) and energy users (EUs) is clarified. And their benefits are clarified in the energy trading strategy. Furthermore, the day-ahead energy trading model, which is a bi-level optimization model is built. In the upper model, the IESP purchases electric energy and natural gas from ESs at wholesale prices and set energy retail prices. According to energy cascade utilization theory, the IESP make decisions on the energy retail plan and energy scheduling. In the lower model, optimal energy consuming plan are given for EUs. In this model, energy grades of energy production, conversion and storage devices output are classified and the energy grade demands of different energy loads are divided. And the energy cascade utilization trading model is simulated based on actual data. The simulation results show that the trading strategy is feasible and the application of energy cascade utilization theory can further improve the energy utilization efficiency of RIES.