海拔和湿度对电机定子绕组相间绝缘起晕电压的影响及校正试验研究  

Experimental Research on the Effects of Altitude and Humidity on the Corona Inception Voltage of Phase Insulation of Stator Winding and Its Correction

作　　者：胡建林[1] 赵禹来 刘剑 汪江昆 丁志远 谭恢林 HU Jianlin;ZHAO Yulai;LIU Jian;WANG Jiangkun;DING Zhiyuan;TAN Huilin(State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Shapingba District,Chongqing 400044,China;Yalong River Hydropower Development Co.,Ltd.,Chengdu 610051,Sichuan Province,China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市沙坪坝区400044 [2]雅砻江流域水电开发有限公司,四川省成都市610051

出　　处：《中国电机工程学报》2020年第22期7460-7468,共9页Proceedings of the CSEE

摘　　要：发电机定子绕组的电晕放电会导致线棒绝缘劣化,引发电机绝缘绝缘故障。高海拔、湿度和温度等大气参数会影响电机绕组的电晕放电特性,开展大气参数对电机定子绕组起晕电压影响的研究对运行于高海拔地区的电机绝缘设计具有重要的工程价值。在多功能人工气候室内对18kV等级大型水轮发电机定子绕组相间绝缘进行不同海拔、湿度和温度的电晕起始特性试验,重点分析海拔和绝对湿度对起晕电压的影响。结果表明:电机定子绕组相间绝缘间隔垫块附近电场较为集中,是电晕放电高发区;定子绕组相间绝缘起晕电压随着海拔的升高(或气压的降低)而降低,综合考虑各大气参数,气压每降低1k Pa,绕组端部起晕电压降低约0.83%;起晕电压随着绝对湿度的增加而降低,总体上的平均递减率约为0.88%/(1g/m3)。该文提出的考虑比湿的起晕电压校正公式包含气压、绝对湿度和温度3个大气参数,可为工程计算电机定子绕组起晕电压作参考。The corona discharge of generator stator windings will lead to the bar insulation deterioration, which will cause insulation failure. Atmospheric parameters such as high altitude, humidity and temperature affect corona discharge characteristics of stator windings. It is of great engineering value to study the influence of atmospheric parameters on the corona inception voltage(CIV) of the stator windings in the insulation design of generators in high altitude areas. In this paper, the corona inception characteristics of the stator winding of a real 18 kV large hydro-generator with phase insulation were tested at different altitudes, humidity and temperatures in the multi-functional artificial climate chamber. The effects of altitude and absolute humidity on CIV were analyzed. The results show that the electric field is concentrated mainly near the insulation spacer block in the phase insulation of stator winding, which is a high incidence area of corona discharge. With the increase of altitude or the decrease of air pressure, the CIV of phase insulation of stator winding decreases. Considering all the atmospheric parameters, the CIV at the end of winding decreases by about 0.83% for per 1 kPa decrease in air pressure. The CIV decreases with the increase of absolute humidity, and the average decline rate is about 0.88%/(1 g/m3). The correction formula of CIV takes specific humidity into consideration and thus includes parameters of air pressure, absolute humidity and temperature, which can be used as the reference point for engineering calculation of CIV of generator stator winding.

关 键 词：定子绕组 相间绝缘 电晕 高海拔 湿度 起晕电压校正 

分 类 号：TM31[电气工程—电机]