一起35 kV干式空心串联电抗器故障原因分析
Fault Analysis of a 35 kV Dry Type Air-core Series Reactor
廖斌 1冯春林 1陈松 1黄桂发1
作者信息
- 1. 桂林电力电容器有限责任公司,广西 桂林 541004
- 折叠
摘要
目前电力系统中户外型并联无功补偿装置的电抗器大多数采用干式空心串联电抗器,在运行过程中,电抗器常因绝缘老化、局部温升过高、过电压、谐波以及环境等因素影响,导致电抗器匝间绝缘损坏击穿、线圈被雨淋时包封表面爬电,甚至局部放电电弧烧毁现象发生.为此本文介绍了某500 kV变电站35 kV并联电容器组的干式空心串联电抗器故障烧毁情况,进行了现场检查和返厂试验;对烧损相和非烧损相均进行了由外向内的包封层解体分析,推断出故障原因为:由于电抗器本体运行了近十年后,电抗器本体包封层的环氧材料劣化开裂,遇雨水天气时潮气浸入包封层内部,长期运行导线绝缘薄膜加速老化,在电容器组多次投切产生过电压,造成电抗器匝间绝缘损坏,最终导致电抗器绝缘击穿、起火烧毁.针对本次事故电抗器损坏情况,提出了相应的预防和处理措施.
Abstract
For the reactor of outdoor shunt reactive power compensation device of present power system,the dry-type air-core series reactor is mostly adopted.During operation period,the influence of such factors of rector as insulation aging,excessive partial temperature rise,over-voltage,harmonics and environment leads to inter-turn insulation breakdown of reactor,surface creepage of envelope due to rainfall of coil and even arc burning due to partial discharge.For this purpose,the burning of dry type air core series reactor of 35 kV shunt capacitor bank at a 500 kV substation is introduced.Inspection at site and test after returning to the factory are performed.The burned phase and non-burned phase are analyzed from the outside to the inside of the envelope layer disintegration and the reason of the failure is deduced as follows:After nearly ten years of operation of the reactor proper,the epoxy material in the envelope layer of the reactor proper deteriorates and cracks.Moisture immerses into the envelope layer in case of rainy weather,and the insulation film of the wire in long-term operation is accelerated to age.The over-voltage due to multiple switching of the capacitor bank causes inter-turn insulation damage of the reactor and finally leads to insulation breakdown and burning of the reactor.As for the damage of reactor in this accident,the corresponding preventive and treatment measures are proposed.
关键词
干式空心串联电抗器/解体/开裂/过电压/绝缘击穿/措施Key words
dry-type air-core series reactor/disintegration/crack/over-voltage/insulation breakdown/measures引用本文复制引用
基金项目
桂林市重点研发计划(20210209-1)
出版年
2024
NETL
NSTL
万方数据