特高压直流换流站阀厅屏蔽效能及设计要求

Shielding Effectiveness and Design Requirement of UHVDC Converter Valve Hall

为了研究特高压直流换流站阀厅的屏蔽效能和设计要求,提出了频率在150 kHz～80 MHz范围内、电场强度≤1 V/m射频干扰强度(120 dB,基准1μV/m对应0 dB)作为邻近换流阀厅外侧的控制指标。结合换流站现场实测数据进行相应的分析及计算,提出阀厅屏蔽设计要求:(1)屏蔽效能目标值取≥20 dB;(2)阀厅屏蔽一般采用直径6 mm、网孔面积200 mm×200 mm的钢筋网;(3)如果墙壁直接采用双层0.6 mm厚镀铝锌压型钢板,每隔30 cm用铆钉连接,两板重合部分宽度>5 cm,则单层板在≤10 MHz范围内的屏蔽效能>40 dB,也可满足要求。

The RF inference no more than 1 V/m caused by the electromagnetic field in the frequency scope of 150 kHz to 80 MHz is considered as the limit specification outside the valve hall.According to the analysis and calculation of the measurement in converter stations,the design requirements for the shielding of valve hall are given as follows：（1） The value of the shielding effectiveness of the valve hall should be larger than 20 dB.（2） The steel wire mesh of wire diameter 6 mm and the side length 200 mm should be used for the shielding.（3） If the sheets are connected every 30 cm with the rivets and the width of the superposition is larger than 5 cm,the shielding effectiveness of single layer sheet achieves 40 dB when the frequency is smaller than 10 MHz.