摘要
某些中性点不直接接地的35 kV短线路因A相装有电容式电压互感器使三相电容参数严重不对称,这导致母线三相电压不平衡。针对这一问题,以110 kV同祥变35 kV母线电压不平衡为例,通过倒闸操作的办法找出导致母线电压不平衡的线路。然后,采用头脑风暴法列出导致系统三相电压不平衡的各种原因,根据电压、电流等一系列异常信号特征找出同祥变35 kV母线电压不平衡的原因是A相电容式电压互感器引起三相电容参数不对称所致。最后,建立PSCAD暂态仿真模型,分析消弧线圈接于不同档位、改变运行方式和电压互感器的不同安装相位时的系统三相对地电压变化情况,所得结果为解决类似原因引起的系统三相电压不平衡问题提供参考。
For certain 35 kV shorter transmission line with neutral point not to earth directly,the imbalance of three-phase voltages of busbar is occurred due to serious asymmetry of three-phase capacitor parameters since capacitive voltage transformer is mounted in phase A. For this issue,the imbalance of 35 kV busbar voltage at 110 kV Tongxiang substation is taken as an example to find out the line causing imbalance of busbar voltage by way of switching operation. Then,various reasons causing imbalance of three-voltage is listed by brainstorming method. It is found that the reason of imbalance of 35 kV busbar voltage is due to asymmetry of three-phase capacitor parameters of capacitive voltage transformer in phase A in accordance with such series of abnormal signal as current and voltage etc. Finally,a PSCAD transient simulation model is set up and voltage variation of three-phase to ground of the system with arc suppression coil mounted at different steps,the change of operation mode and at different installation phase of voltage transformer are analyzed,and the result obtained can provide reference in solving the imbalance of threephase voltage of the system due to similar reasons.
出处
《电力电容器与无功补偿》
北大核心
2015年第5期80-87,共8页
Power Capacitor & Reactive Power Compensation
关键词
电压不平衡
电容式电压互感器
35
kV短线路
倒闸操作
三相参数不对称
对地电容
消弧线圈
脱谐度
voltage imbalance
capacitive voltage transformer
35 kV short line
switching operation
asymmetry of three-phase parameters
capacitance to ground
arc suppression coil
off turning
