城市轨道交通供电系统无功平衡分析

基于部分城市轨道交通供电系统公共连接点(PCC)功率因数小于0.9的现象,分析了影响供电系统功率因数的主要无功来源,分别为110 kV电缆容性充电无功、主变电所主变压器感性无功、35 kV环网电缆容性充电无功和动力照明负荷感性无功。阐述了几种目前使用较为广泛的无功补偿方法,介绍了功率因数、电缆容性无功、主变压器无功的计算公式。以南昌轨道交通某主变电所为案例,对其无功容量及补偿需求容量进行计算,在此基础上总结出城市轨道交通供电无功平衡的合理措施。

Reactive Power Balance Analysis of Urban Rail Transit Power Supply System

Based on the phenomenon that PCC(point of common connection)power factor of some urban rail transit power supply systems is lower than 0.9,the main reactive sources that affect the power factor of power supply system are analyzed,which are detected as the capacitive charging reactive power of 110 kV cable,inductive reactive power of transformer,charging reactive power of 35 kV loop network cable and power lighting load respectively.Then,the reactive power compensation methods widely used at present are elaborated,the calculation formula of power factor,cable capacitive reactive power and main transformer reactive are introduced.According to a main substation of Nanchang rail transit,the reactive power capacity and compensation demand capacity are calculated,reasonable reactive power balance measures for urban rail transit power supply are summarized.