蒸发冷却对高压电机电场分布改善的研究

为尽早开发国内24 kV级大型汽轮发电机,提出了采用蒸发冷却方式的技术路线。根据蒸发冷却介质高绝缘性能提出了一种适于该冷却方式的高电压等级汽轮发电机新型定子绝缘结构。采用有限元数值计算软件仿真了电机定子槽内与端部高压静电场的分布状况,列出了若干组电场强度的计算结果,据此详尽地分析了蒸发冷却方式下形成的气、液、固三态绝缘系统的耐电晕、耐击穿的可靠性,系统地研究了新定子绝缘结构的特点及规律。结果表明该新型绝缘系统无需防晕处理,可实现主绝缘仅4 mm的24 kV等级蒸发冷却汽轮发电机。

Research of Evaporative Cooling Method for Improving Electric Field of High Voltage Generator

In order to develop the first inland 24 kV rated voltage turbogenerator,this paper proposes to adopt an evaporative cooling method to realize it.According to the high insulation capability of evaporative cooling medium,this paper gives a new kind of stator insulation structure that is suitable to evaporative cooling mode and can be applied to high voltage level.By finite element method calculation software,this paper simulates the static electric fields in the slot and the end of a high voltage generator stator.Then this paper analyzes in detail the three-phase insulation system consisted of gas,liquid and solid formed by evaporative cooling mode,including the reliability of its anti-corona and anti-breakdown.After a series of researches on insulation characteristic and laws of the new structure,a conclusion that if the new insulation system is designed in reason it is feasible to 24 kV rated voltage, is obtained.