摘要
水内冷发电机定子绕组冷却水路堵塞引起的股线绝缘局部高温会造成股线绝缘短路,加剧电机故障的严重性。该文建立了1000MW超临界汽轮发电机定子流体场与温度场共轭传热计算模型,得到了定子采用氢气冷却时定子铁心表面散热系数的分布规律;分析了定子冷却水路堵塞时,股线绝缘四周的温度变化规律,研究了股线绝缘温度与股线堵塞位置及根数的关系,发现两根股线同时堵塞时,堵塞处股线绝缘的温度受堵塞股线之间的距离影响显著;研究了定子冷却水路排布对定子股线绝缘温度分布的影响,发现采用新冷却水路排布结构后,发生堵塞故障时,股线绝缘最高温度降低44.3℃。所作研究为股线绝缘性能受堵塞股线的影响程度提供了理论依据,可以有效预防股线绝缘因温度过高损坏而发生股线短路事故的发生。
The local high temperature of the strand insulation caused by the blocking failure in water cooled turbo-generator will cause the inter-turn short circuit, which will increase the severity of the faults. In this paper, the conjugate heat transfer model of 1 000 MW supercritical turbo-generator was established. The heat transfer coefficient of the stator core surface cooling by hydrogen was obtained using finite volume method. The temperature change laws of the strand insulation with blocking hollow strands was investigated. The relationship of strand insulation temperature and blocking strand numbers and locations was studied. The study finds that the strand insulation temperature is effect observably by the distance of blocking strand when two strands were blocked simultaneously. The influences of a new stator cooling structure on the strand insulation temperature were studied. Adapting the new structure, the highest temperature of the strand insulation can be reduce 44.3 ~C when the hollow strands were blocked. The research for the influence of the blocking degree on strands insulation performance provide theory basis, which is helpful for preventing strand insulation short caused by high temperature in strand insulation.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第15期141-148,5,共8页
Proceedings of the CSEE
基金
国家自然科学基金项目(51077031)~~
关键词
水内冷汽轮发电机
流体场
温度场
股线堵塞
绝缘性能
water cooled turbo-generator
fluid field
temperature field
blocking hollow strands
insulating property
