变电站隔离开关操作产生的电磁暂态特征量研究

Research of Electromagnetic Transient Characteristics in Substations Due to Disconnector Switching

变电站隔离开关操作产生的电磁骚扰是电力系统二次设备防护的重要内容。基于真型实验场开展了一系列实验,在AIS和GIS内进行了一系列不同电压等级不同容性负载的隔离开关分合闸重复实验。由于隔离开关操作持续时间长,采样率高,采集得到的实测数据十分庞大,为了方便处理实测数据,设计了一种自动计算的模型既能实现隔离开关全过程多次放电脉冲群的特征量提取,也能实现单次击穿波形的分离和计算。计算结果显示AIS隔离开关操作产生的电磁骚扰主频在300~600 kHz,有些文献中测量结果高达几MHz,GIS产生的电磁骚扰在17~20 MHz。暂态电流及其耦合的电磁骚扰主频仅受变电站结构和参数影响,相同实验条件下GIS产生的地电波比AIS幅值更高主频更大振荡更强烈。该实验结果为电力系统开展针对二次设备的电磁防护试验提供了量化参数。

Electromagnetic interference caused by substation isolation switch operation is an important part of secondary equipment protection of power system.Therefore,a series of experiments were carried out based on the real type test site,and a series of repeated experiments on the opening and closing of the isolation switch under different voltage levels and different capacitive loads were conducted in AIS and GIS.The isolation switch has a long working time and the high sampling rate,thus the collected measurement data are very large.In order to facilitate the processing of measurement data,an automatic calculation model is designed,which can not only realize the extraction of multiple discharge pulse groups in the whole process of isolation switch,but also realize the separation and calculation of a single breakdown waveform.The calculation results show that the main frequency of electromagnetic interference generated by AIS isolation switch operation is 300~600 kHz,and the main frequency of electromagnetic disturbance generated by GIS is 17~20 MHz.The main frequency of the transient current and its coupled electromagnetic interference is only affected by the substation structure and parameters.Under the same experimental conditions,the ground wave generated by GIS has higher amplitude,larger main frequency and stronger oscillation than AIS.The experimental results of this paper provide quantitative parameters for electromagnetic protection test of secondary equipment of power system.