电热联合系统潮流计算

Power Flow Calculation of Combined Heat and Electricity System

热力系统和电力系统通过电热耦合元件耦合后形成了电热联合系统。电热联合系统潮流计算能为电热联合系统后续的规划、运行、调度打下基础。文章以传统的水热联合模型为基础,根据量调节方式下的热网模型,建立了质调节方式下的热网模型。在此基础上对比研究了顺序计算法、联合计算法等2种电热联合系统潮流计算方法。顺序计算法依次计算热力系统潮流、"以热定电"功率和电力系统潮流,方法原理简单且计算量小;联合计算法则是将热力系统、热电耦合元件和电力系统等3个部分的方程联立,然后用牛顿–拉夫逊法计算,计算精度相当高。算例仿真及对比分析表明,顺序计算法更适用于以热定电的电热联合系统的潮流计算,而联合计算法更适用于电热相互影响的电热联合系统潮流计算。

Through electrothermal coupling component, the heat network and the electricity network are coupled, thus forming a combined heat and power system. Power flow calculation of the combined heat and power system lays the foundation for the subsequent planning, operation and dispatch of the combined heat and power system. This paper establishes a heat network model with quality regulation, which is based on the traditional combined heat and water model. On this basis, two calculation methods, sequential flow method and combined flow method, are compared for the power flow calculation of the combined heat and power system. The sequential flow method, which is simple, needs less computing resource, sequentially calculates the heat power flow of the heat network# the associated electrical power consumption/production, and the electrical power flow of the electricity network. The combined flow method, which has a quite high accuracy, combines equations of the three sub-models in the combined heat and power network, and is solved by the Newton-Raphson method. Simulation of a numerical example and a comparison of the results show that sequential calculation method is more sxiitable for the power flow calculation of the combined heat and power system if electricity production is a result of heat load, while the combined flow method is more suitable for the power flow calculation of the combined heat and power system wherein the heat and electricity production influences each other.