城市轨道交通运行对城市电网谐波的影响研究

A Study Concerning the Impact of Urban Rail Transit Operation on the Harmonic of Urban Power Grid

针对城市轨道交通的实际投运会对城市电网的电能质量产生影响,尤其是可能会在系统公共连接点(point of common coupling,PCC)处产生不利于电网安全、稳定运行的高次谐波,本文在考虑地铁列车牵引、惰行、制动3种具体运行工况的前提下,构建了基于24脉波整流方式的城市轨道交通牵引供电系统及地铁列车的运行模型,并对地铁列车投运后在不同运行工况下对电力系统公共连接点处的电能质量进行了仿真测算和谐波分析。分析结果表明,城市电网在列车处于牵引、制动两种运行工况时的特征次谐波较大,而在列车处于惰行工况时的谐波值较小。该研究不仅精确地展现了列车的行驶状态,还反映出当列车处于不同运行工况时对网侧谐波的影响情况,为今后地铁系统公共连接点处谐波的精准化治理提供了理论依据。

Since the power quality of grid can be influenced： especially higher harmonics working against the safety and stability of the grid might be produced at the point of common coupling of this system-by the prac-tical operation of urban rail transit, the study, under the promise of concerning the three conditions including traction, coasting, and braking, builds an urban rail traction power supply system based on the 24 - pulse recti-fier system and an operation model of a train. Meanwhile, it makes both simulation and harmonic analysis which are regarding the power quality at the point of common coupling under different working conditions after the train is put into running. The result reveals that far larger characteristic harmonics are present in the urban grid when the train is under the two conditions of traction and braking, whereas there are the smaller in the train＇s coasting situation. The study not only accurately illustrates these separate states of the operation of the train, but also reflects on the influences of the train on the grid under various running conditions. It may offer a theoretical basis to the next precise control over the harmonics at the point of common coupling of the subway system.