110 kV变压器中性点雷击闪络故障分析及防治措施

摘要

In order to work out over-voltage on insulated neutral point of 1 1 0 kV transformer under lightning current impact, line cake model was used for modeling for 1 1 0 kV transformer winding and PSCAD software was adopted for simulating cal-culation on this model. Simulating analysis was carried out for breakdown of 1 1 0 kV transformer neutral point in Guangzhou region by using this model and the result indicates that it is not enough to prevent lightning by only installing discharge gap for transformer neutral point and the fault rate of neutral point reaches up to 0.686 times a year when lightning wave inva-ding the transformer which explains that it needs to combine other control measures for protection on the transformer neu-tral point in this region. According to simulation result,transformation measure of using 130 mm gap in parallel connection with Y1.5 W-72/1 86 typed arrester is proposed.%为获得雷电流冲击下110 kV变压器不接地中性点上的过电压，采用线饼模型对110 kV 变压器绕组进行建模，并用 PSCAD仿真软件对该模型进行仿真计算。利用该模型对广州地区110 kV 变压器中性点击穿事故进行仿真分析，结果表明对变压器中性点仅加装放电间隙不足以防止雷电侵害，并且雷电波入侵变压器时中性点故障率高达到0.686次/年，说明需要结合其他防护措施对这一地区变压器中性点进行保护。根据仿真结果提出采用130 mm的间隙并联Y1.5W-72/186避雷器实施改造措施。