With the development of China's clean energy and environmental protection system, it is of great significance for China to build a clean energy and environmental protection system, To realize the optimization of energy structure, this paper briefly introduces the advantages of comprehensive energy system.

The concept of integrated energy system breaks through the technical, market and management barriers of traditional energy systems. It is a comprehensive energy system with unified planning and dispatching of all kinds of energy, such as electricity, gas, heat and cold. It is of great significance to promote the transformation of energy structure and promote China's energy revolution. The comprehensive energy system is bound to become the main form of energy system in the future.

All kinds of typical physical equipment and their mathematical models in the integrated energy system have not been systematically combed and summarized. At the same time, the theoretical system suitable for comprehensive energy benefit evaluation has not been established, and the economic, environmental and social benefits that the system can bring are still in the conceptual stage. Therefore, based on the relevant research and exploration at home and abroad, this paper summarizes and analyzes the research status and theoretical results at home and abroad in the basic architecture, system model and comprehensive benefit evaluation system of the comprehensive energy system, combs the shortcomings of the current research, and looks forward to the key research directions and key problems of the comprehensive energy system modeling and comprehensive benefit evaluation in the future.

At present, studies at home and abroad have proposed that energy Internet [5], energy hub [6] and universal energy network are the manifestations of integrated energy system. At the level of basic physical structure and equipment of the system, the integrated energy systems of various forms are basically the same, including the production, transmission, storage and consumption equipment of electric, heat, cold and gas energy.

According to the types of energy and quality carried by the equipment, all kinds of equipment in the integrated energy system can be divided into independent equipment unit and coupled equipment unit. In the independent equipment unit, the electricity / heat / gas / cooling maintains its own unique energy and quality attributes, and there is no coupling conversion and complementary utilization between heterogeneous energy flows. The coupled equipment unit can realize the mutual conversion and utilization of electricity / heat / gas / cooling.

The development of integrated energy system can be said to be an important measure to benefit the country and the people. Although China lags behind the developed countries in Europe and the United States in this regard, with China's continuous investment in energy reform, the integrated energy system will be greatly improved in the future.