高压直流换流站换流阀电磁干扰的测量

针对目前缺乏国内换流站阀厅电磁骚扰特性的研究,高压换流站阀厅电磁屏蔽效能的设计缺乏依据的问题,采用环状天线、双锥天线、对数周期天线和ESCI无线电干扰接收机,在国内4个典型换流站实测了换流阀的电磁干扰。测量结果表明:在阀厅内距墙壁1m处150kHz～1GHz频段的电磁干扰水平最大值范围为102～105dB(基准1μV/m,下同);在9～150kHz的低频段换流阀厅内距墙壁1m处的电磁干扰最大值为140dB。测量分析指出,换流阀所发出的电磁干扰水平随频率的增高衰减很快,最主要的高幅值场强出现在低频段特别是<1MHz,频率>10MHz的电磁干扰水平基本<60dB,而且在频率>10MHz以后的干扰水平与换流阀停运后的背景噪声水平基本一致。换流阀所发出的电磁干扰水平与换流阀输送功率没有明显的相关性。

Characteristics of Electromagnetic Disturbance in HVDC Valve Hall

To investigate the characteristics of electromagnetic disturbance in HVDC,by means of loop antenna,bi-conical antenna,log-periodic antenna and ESCI EMI receiver,electromagnetic disturbance of converter valves was tested in valve hall of Gezhouba,Jiangling,Lingbao,Longquan converter stations.Tested results show that in the frequency scope of 150 kHz to 1 GHz,the maximum electromagnetic disturbance levels are 102 to 105 dB at 1m close to the wall in the valve hall,and in the low frequency scope of 9 kHz to 150 kHz,the maximum level is 140 dB.It is indicated that with the frequency increasing,the electromagnetic disturbance level quickly decreases in the valve hall.And the most high intensity occurs in a low frequency range,especially below 1 MHz.Above 10 MHz,electromagnetic disturbance level is less than 60 dB,and above 10 MHz,the level when valve is in operation is nearly equal to background disturbance level when valve packs up.The level caused by the valves is not obviously related with transmission power.