考虑天然气动态特性的电-气综合能源系统经济优化调度

Economic Optimization of Electric-gas Integrated Energy System Considering Dynamic Characteristics of Natural Gas

针对综合能源系统经济优化调度中,天然气模型大多采用理想假设条件,建模分析结果不够精确的问题,提出了一种考虑天然气流动特性的天然气动态模型。首先,采用特征线法对天然气数学模型进行线性化处理,得到天然气动态模型,依据该模型可计算得出天然气流量和压强。其次在电-气综合能源系统模型的基础上,建立以运行成本最低为目标函数的电-气综合能源系统经济优化调度模型,根据已计算得出的天然气流量和压强进行经济优化调度分析。通过仿真算例分析验证得出,所提出的天然气动态模型比天然气稳态模型更能真实反映天然气流动过程,依据该模型可得到更准确的电-气综合能源系统经济优化调度方案,有效提高了可再生能源的消纳率和能源利用效率。

At present, most natural gas models used in economic optimal dispatch of integrated energy system are based on ideal assumptions, and the results of modeling and analysis are not quite accurate. For this situation, a natural gas dynamic model considering the flow characteristics of natural gas is proposed. Firstly, by linearizing the mathematical model of natural gas with the characteristic line method, the dynamic model of natural gas is obtained, with which the flow rate and pressure of natural gas can be calculated. Secondly, on the basis of the integrated electricity-natural gas system model, the economic optimal dispatching model of the system is established with the lowest operating cost as the objective function, and the economic optimal dispatching analysis is carried out with the calculated natural gas flow and pressure. The simulation results show that the dynamic model of natural gas proposed in this paper can more truly reflect the flow process of natural gas than the steady-state model. According to this model, more accurate economic optimal scheduling scheme of the integrated electricity-natural gas system can be obtained, which can effectively improve renewable energy consumption and energy utilization efficiency.