变压法在大型电力变压器干燥过程中的应用

Application of vacuum-changing method for large capacity transformer’s drying process

水分是影响大型电力变压器寿命的重要因素之一,常规的干燥方法容易使绝缘表层毛细管萎缩,影响绝缘深层水分的蒸发,同时,由于受蒸汽压力和干燥罐真空度等等多方面的影响,PID控制器参数难于整定,经常产生很大的超调。采用变压法后,控制器执行器采用可编程控制器,人机界面采用在工控机平台下的组态软件,系统运行后稳定可靠,变压器干燥取得了很好的经济和社会效益。

Moisture is the main factor for the infection of man-sized power transformer＇ s life-span, the atrophy of capillary of insulating layer is easily made by normal dry technology, so moisture of insulating deep layer is affected. The tuning of parameter of PID controller is quite difficult, because of the main vapor pressure and the vacuum degree and so on, big overshoot is often produced. The vacuumchanging method based on PLC is designed to solve the problems, configuration software is used in human interface station. Practical operation results show that the method is effective, this experiegce makes great reference for practical using.