基于恒功率负荷的牵引供电系统潮流计算

A Power Flow Analysis Method of Traction Power Supply System Based on Constant-power Load

采用电力系统的潮流迭代算法进行牵引供电系统潮流计算。建立了牵引供电系统数学模型,将机车负荷作为恒功率模型,根据机车负荷和供电电压,分别采用牛顿-拉夫逊法和前推回代法,进行了直供和AT牵引供电系统潮流计算,通过典型算例比较了其与传统简化方法(机车负荷为恒电流模型)在机车网压计算的差异。结果表明,传统算法误差较大,尤其是在高速重载工况下误差更大,而电力系统潮流迭代方法进行牵引计算的精度更高。

This paper introduces a method to the traction power supply system based on power flow iterative algorithm of the power system. Mathematical models of the traction power supply system are established. The locomotive load is regarded as a constant-power model instead of a constant-current one. The Newton-Raphson method and forward and backward substitution method are used to calculate the voltage of locomotive and voltage loss of traction network and traction transformer respectively,and both direct power supply system and AT fed system are taken into consideration.The results are compared with those calculated by the traditional simplified method for the same typical examples. It shows that there are large deviations in the results of power flow calculation for traction power supply system using the traditional simplified method,especially in high-speed or heavy-load conditions,while the accuracy of results by power flow iterative algorithm is much higher.