综合能源系统通过电、气、冷/热等多种形式能源的相互耦合、转化和资源分配，实现了能量梯级利用，提升能源综合利用率以及能源供应的灵活度。然而，不同类型的能源系统其能流性质以及传输特性各异，这阻碍了综合能源系统的统一建模和整体分析，难以实现和发挥综合能源系统的整体协同。从能量网络理论出发，基于能量公理化的思想，建立流体网络以及热力网络传输的等值电路模型；结合能量转换设备模型，完成多能流耦合系统的统一建模。随后，以系统总能量损失最小为目标，建立区域综合能源系统运行优化模型，通过粒子群算法对系统内部控制变量进行决策寻优。最后，对某岛屿32热力节点综合能源系统进行建模以及运行优化，验证所提模型以及优化方法的有效性。

Coupling various forms of energy, such as electricity, gas, cold/heat and other forms of energy, the integrated energy system has realized the cascade utilization of energy, enhanced the comprehensive utilization of energy and the flexibility of energy supply through the energy conversion and resource allocation between its sub-systems. However, the energy flows in different types of energy systems vary in their transmission characteristics, which hinders the unified modeling and overall analysis of the integrated energy system, so it is difficult to achieve and bring into play the overall coordination of the integrated energy system. In this paper, based on the theory of energy network and the axiomatic energy theory, the electrical equivalent model of the transmission line in thermal network and the fluid network are established. Combined with the energy conversion equipment model, the unified modeling of the multi-energy flow systems is completed. Then, taking the minimum total energy loss of the system as the goal, a regional integrated energy system operation optimization model is established, in which the particle swarm optimization algorithm is used to optimize the internal control variables of the system. Finally, an integrated energy system of an island with 32 thermal nodes is modeled and optimized, which verifies the validity of the proposed model and optimization method.