35kV变电站风险评估及改造措施

The Risk Assessment and Improvement Measures of 35 kV Substation

对山西煤矿集团鑫顺矿业35 k V变电站现有的进线线路绝缘配合、主变变压器接地以及变电站内部设备防雷措施进行了风险评估,并提出线路加装保护间隙、对变电站进行进线段保护设计、杆塔安装冲击散流装置、主变接地系统外引环形接地网以及变电站内部采用特种防雷变压器等精细化、差异性防雷改造措施,同时在实验室对保护间隙进行50%U的冲击试验,得出保护间隙最佳距离,并采用电磁暂态软件ATP-EMTP对线路安装保护间隙、外引环形接地网进行仿真计算和验证,从而得出此种精细化、差异性防雷改造措施。

Taking the 35 k V substation in Shanxi coal mining as example, the line insulation coordination of current entrance lines, grounding of the main transformer and the protection measures against lightning of the equipment in the substation are analyzed, and the risk evaluations are made.Some suggestions and measures are presented such as installing protection gap to the lines, protection design of the entrance line to the substation, installing impulse current dispersing device on the tower,adding ring-type grounding grid to the grounding system of the main transformer, and using special transformer in substation to prevent from lightning. Meanwhile, the 50% impulse voltage discharge tests of the protection gap are made in laboratory so as to get the optimization protection clearance. The electromagnetic transient software ATP-EMTP is used to make simulation and verification of the protection gap for line installation and external grounding ring in order to realize a fine and difference lightning transformation measures.