±1100 kV特高压直流穿墙套管交、直流局部放电试验净空区域优化

Optimization of Clearance Test Area for ±1 100 kV UHVDC Wall Bushing in AC and DC Partial Discharge Measurement

为准确测量±1 100 kV特高压直流穿墙套管交、直流试验电压下的局部放电量水平,验证其绝缘设计、材料选型、制造工艺的合理性,提出了低背景干扰的局部放电试验净空区域优化方法;利用电磁屏蔽试验空间内穿墙套管试验布置的有限元仿真模型计算了交流1 273 kV和直流+1 683 kV下的空间电场分布;通过测量接地尖端电极交流局部放电量、高电位均压环直流局部放电脉冲,得到了用于±1 100 kV直流穿墙套管交、直流局部放电试验净空区域优化的基准场强;通过对比净空区域优化前后局部放电背景干扰水平,验证了所采用的交、直流局部放电试验净空区域优化方法的正确性。研究结果可为有限电磁屏蔽试验大厅内特高压直流设备交、直流局部放电试验干扰信号识别和抑制提供方法和依据。

In order to accurately measure partial discharge on ±1 100 kV UHVDC wall bushing under AC and DC test voltage,and to verify the rationality of insulation design,material selection,and manufacturing process,we proposed an optimization method of clearance area with low background interference during partial discharge test.The electric field distribution of test area with wall bushing in the electromagnetic shielding hall was calculated using the finite element method under 1 273 kV AC and 1 683 kV DC voltage.On the basis of the AC partial discharge magnitude measurement results of a pointed grounding electrode in different locations,and using the DC partial discharge pulse measurement result of a high potential shielding ring in different areas,we obtained the reference electric fields for the optimization clearance area of ±1 100 kV UHVDC wall bushing during the AC and DC partial discharge measurement test.The optimization method of AC and DC partial discharge clearance area is verified by using the comparative test of the background interference level.The optimization method of clearance area during partial discharge test proposed in this paper can be used to identify and suppress the partial discharge interference signal for other ±1 100 kV UHVDC equipment.