“源-网-荷-储”式异质能流复合供能系统的研究现状及发展趋势

The development of a “generation-grid-load-storage” type integrated system with heterogeneous energy flows is necessary to construct a high-quality energy industry and improve the consumption level of renewable energy. Accelerating its development is significant to construct a multi-energy complementary, flexible and intelligent energy system and to achieve the carbon peaking and carbon neutrality goals. At present, the transformation and upgrading process of the energy system is speeding up in China. Compared to the conventional energy system, the new “generation-grid-load-storage” type of integrated systems with heterogeneous energy flows is more complex. It involves the processes of acquisition, integration, conversion, and transportation of various energy forms including cooling energy, heating energy, electricity, and gas. The demand of diversified energy utilization and the objective of higher energy conversion efficiency are both achieved. In view of these issues, this paper believes that the characteristics of multi-energy flows, multi-grade energy distribution, multiple time scales and space scales of the energy systems are becoming remarkable with the increase of complexity of the generation-grid-load-storage energy system. It also leads the new challenges of theoretical and technical problems to the efficient utilization of energy. Besides, to realize the collaborative development of the generation-grid-load-storage energy system with heterogeneous energy flows, it is necessary to break through the limitations of the energy conversion analysis of single energy flow system primarily. The coupling logic between different energy systems needs to be elaborated from the perspective of energy quality and energy grade to guide the optimization of energy structures and conduct energy control. Moreover, the difficulties in multi-scale collaborative responses of heterogeneous energy flow systems are required to be solved because of the more obvious nonlinear characteristics and the instability of the system. Thus, this paper states the composition and characteristics of the generation-grid-load-storage type of heterogeneous energy flow systems at first. The functions and features of the physical layer, interaction layer, and information layer are described respectively. The relationships between layers are clarified. Second, the modeling method of energy coupling and conversion is introduced to clarify the theoretical basis of heterogeneous energy flow systems. The importance of energy utilization and the realized method of energy grade matching are further expounded for building an efficient energy cascade utilization system. They are also significant to realize orderly and on-demand energy conversion. The essential role of renewable energy taking in the high-efficient energy utilization system is introduced with an emphasis. Furthermore, the dynamic response characteristics of heterogeneous energy flow systems are summarized from the perspective of time scales and space scales. The role of digital twin technology taking in heterogeneous energy flow systems is described to present its importance to construct intelligent energy systems. The research status and challenges of collaborative regulation, structural optimization, and energy control are illustrated. Meanwhile, the introduction of the authors’ team work is displayed including high-efficient energy conversion analysis of the heterogeneous energy flow system, dynamic response characteristics of systems under real-time microgrid load and the optimized energy management method. Finally, some recommendations of the future development of energy systems are presented from aspects of theoretical, methodological and technical perspectives.