电压互感器二次绕组中性点保护措施研究  

Research for the Neutral Point Protection Measures of Voltage Transformer’s Secondary Windings

作　　者：李谦 郑晓光 饶章权 刘玮[2] 梁文进[2] 袁亮荣[3] 游伏生[4] 林福昌[5] 刘琦[5] 曾嵘[6] 

机构地区：[1]广东电力科学研究院,广州510600 [2]广东电网公司,广州510600 [3]广东省电力调度中心,广州510600 [4]广东省电力设计研究院,广州510663 [5]华中科技大学,武汉430074 [6]清华大学,北京100084

出　　处：《南方电网技术》2009年第1期41-44,共4页Southern Power System Technology

摘　　要：实施雷电侵入、雷直击和工频接地故障状态下电压互感器二次绕组中性点的雷电传递和地网两点间电位差的实验和仿真研究。结果显示:雷电冲击波头对二次侧振荡峰值的影响非常明显,电压型和电容型电压互感器的传递过电压幅值均随波头时间的缩短而上升;加装避雷器保护后传递到二次绕组中性点的过电压得到了明显的限制,表明低压无间隙金属氧化物避雷器(MOA)适用于电压互感器二次绕组中性点过电压保护,但所选择的避雷器额定电压要与实际情况相适应。Experimental and simulation studies are carried out on the lightning transfer in the neutral point of the voltage transformer＇s secondary winding and the potential difference between two points of ground network in the situations of lightning invasion, direct lightning stroke and power frequency grounding fault. The results show that the risetime of lightning surge wave has obvious influence on the over-voltage level of lightning transmission at the neutral point of the secondary winding, and the breadth values of the level for both the voltage-type and capacitance-type voltage transformer increase rapidly as the risetime of lightning suge wave decreases. The over-voltage level is limited greatly by an an＇ester, indicating that the ZnO arrester （MOA） can work well for protection against the over-voltage of the neutral point of the secondary winding, but it should be careful to choose suitable rating voltage of the arrester.

关 键 词：电压互感器 二次绕组中性点 过电压保护 氧化锌避雷器 

分 类 号：TM451[电气工程—电器] TM743