摘要
某核电厂一台百万千瓦汽轮发电机定子绕组在安装结束后进行定子绕组交流耐压交接试验过程中,C相和A相先后发生了对地击穿。经分析,原因是定子绕组下半过渡引线软连接沿上绝缘块拼接处缝隙、通过绝缘盒固定绝缘螺杆到达压电式测振探头及其引线发生了沿面放电。通过将压电式测振探头改进为主绝缘级的光纤式测振探头,并对绝缘盒固定螺杆进行环氧树脂密封切断放电路径,三相交流耐压试验全部顺利通过。至今此发电机已经运行超过3年,在线局放监测数据显示定子绝缘情况良好。
During a 1000 MW turbine generator stator winding AC withstand voltage test,there were insulation break down in phase C and phase A.After analyzing,the discharge along surface was found from the insulation pieces connection gap of the stator winding lower dropper connection to the piezoelectric vibration sensor and its cable.By changed the piezoelectric vibration sensor to optical fiber vibration sensor and seal the discharge path inside the insulation box with epoxy to avoid discharge,the 3 phases AC withstand voltage test has successful.So far the generator has operated over 2 years and online partial discharge system shows the stator winding insulation is good.
出处
《大电机技术》
北大核心
2014年第4期27-29,共3页
Large Electric Machine and Hydraulic Turbine
关键词
发电机
交流耐压
沿面放电
压电式测振探头
光纤式测振探头
generator
AC withstand voltage test
discharge along surface
piezoelectric vibration sensor
optical fiber vibration sensor
