【作者】 赵斌； 郭宝甫； 姚晴林； 蔡常群； 唐云龙；

【Author】 ZHAO Bin~1 GUO Bao-fu~1 YAO Qing-lin~2 CAI Chang-qun~1 TANG Yun-long~1(1.XJ Electric Company,Xuchang 461000;2.Hefei Technical University,Hefei 230009)

【机构】 许继电气公司； 合肥工业大学；

【摘要】 我国发变组的升压变压器都是Y0/△-11或Y/△-11接线,其传统的低阻抗保护装在主变低压侧为三个低阻抗继电器(线电压及相电流之差的0°接线方式)构成"或"门延时出口。本文通过分析及动模试验,认为这种传统方案是不宜采用的,主要理由是主变高压侧两相短路时,这三个继电器的测量阻抗都远大于短路点至保护安装点之间的阻抗,都会拒动,它不能保护主变高压侧的两相短路。本文还分析了若干种正确的Y0/△-11变压器低阻抗保护方案的特征及其优缺点。更多还原

【Abstract】 The upgrade transformers of generator & transformer units are all Y0/△-11 or Y/△-11 connection mode in our country. The traditional low impedance is fixed at the low voltage side of the main transformer.The three low impedance relays compose"or"logic and trip by time-lag.In this paper,the traditional scheme is thought to be inadvisable by analysis and dynamic stimulant test. The main reason is when the two phase short circuit,the metrical impedance of the three relays are all much higher than the actual impedance,so they all don’t operate.So it can’t protect the two phase short circuit of the main transformer high voltage side.The characteristic and strongpoint or shortcoming of some correct Y0/△-11 transformer low impedance protection are analyzed in this paper.更多还原