Abstract
The integrated energy system is the mainstream energy utilization form of integrating a power system, natural gas system and thermal system, which provides a new way to solve the problem of renewable energy accommodation. The integrated energy system includes a variety of energy generation and conversion equipment, and its internal electricity, gas, cooling and thermal systems must balance the multiple energy supplies required by users. The integrated energy supplier (IES) and integrated energy user (IEU), as different stakeholders, pursue the maximization of their own profit. However, integrated energy suppliers should consider their market share and the sustainability of participating in market competition. Based on the constraints of energy access, conversion and accommodation, and the equipment for energy generation, conversion and consumption, we established an energy flow model. Constrained by the dynamic equilibrium of the supply of integrated energy suppliers and the demand of integrated energy users, a Stackelberg game model of integrated energy suppliers and users was established, and the existence of a Nash equilibrium solution of the game was proved. A genetic algorithm was used to solve the Nash equilibrium solution under two conditions aiming at the integrated energy supplier’s maximum profit and target profit. Considering the demand of integrated energy users in different time periods, we analyzed the time-of-use pricing strategy of the integrated energy based on the balance of the energy supply and demand. The results of a case study show that if integrated energy suppliers adopt the time-of-use pricing strategy of maximum profit, the energy load distribution of integrated energy users can be smoothed, and energy utilization and economic benefits of the system can be improved. If integrated energy suppliers adopt the time-of-use pricing strategy of target profit, enlarge the market by limiting their own profit and obtain the purchase willingness of integrated energy users by reducing the energy price, they can have a larger market share, a more reliable profit and a guarantee of long-term participation in market transactions.