To alleviate environmental pollution and improve the energy efficiency of end-user utilization, the integrated energy systems (IES) have become an important direction of energy structure adjustment over the world. The widespread application of the coupling units, such as gas-fired generators, gas-fired boilers, and combined heat and power (CHPs), increases the connection between electrical, natural gas, and heating systems in IES. This paper proposes a mixed-integer nonlinear programming (MINLP) model combining electrical, natural gas, and heating systems, as well as the coupling components, such as CHPs and gas-fired generators. The proposed model is applicable for either the radial multi-energy network or the meshed multi-energy network. Since the proposed MINLP model is difficult to be solved, the second-order-cone and linearized techniques are used to transform the non-convex fundamental matrix formulation of multi-energy network equations to a mixed-integer convex multi-energy flow model, which can improve the computational efficiency significantly. Moreover, the potential convergence problem of the original model can also be avoided. A simulation of IEEE 14-node electrical system, 6-node natural gas system, and 23-node heating system is studied to verify the accuracy and computational rapidity of the proposed method.

中文翻译：

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综合能源系统考虑凸网约束的多能流计算

为缓解环境污染，提高终端用户利用能源效率，综合能源系统（IES）已成为全球能源结构调整的重要方向。燃气发电机、燃气锅炉和热电联产 (CHP) 等耦合单元的广泛应用增加了 IES 中电力、天然气和供暖系统之间的联系。本文提出了一种混合整数非线性规划 (MINLP) 模型，该模型结合了电力、天然气和加热系统，以及耦合组件，例如 CHP 和燃气发电机。所提出的模型适用于径向多能网络或网状多能网络。由于提出的 MINLP 模型难以求解，利用二阶锥和线性化技术将多能网络方程的非凸基本矩阵公式转化为混合整数凸多能流模型，可显着提高计算效率。此外，还可以避免原始模型潜在的收敛问题。对IEEE 14 节点电气系统、6 节点天然气系统和23 节点加热系统进行了仿真研究，以验证所提出方法的准确性和计算速度。