蒸发冷却介质两相流状态下工频击穿特性的实验研究

一些不燃型氟碳化合物具有非常好的绝缘特性,既可以作为蒸发冷却变压器等电气设备的冷却介质,也可以作为绝缘介质,使得蒸发冷却变压器不燃不爆、安全可靠、经济高效、绿色环保、成本适中,适用于某些特定场合的需求。在作为绝缘介质实际运行过程中,氟碳化合物将以气液两相流状态存在。为研究该工况下介质的绝缘性能,本文参考国家标准研制了实验装置,测量了若干种氟碳化合物介质在两相流状态下的工频击穿电压特性。实验采用3mm间隙的板-板电极,得到了不同工作压力下的工频击穿实验数据,以及击穿电压与工作压力的经验公式。实验结果的统计分析显示两相流状态下工频击穿数据很好地服从于威布尔分布和正态分布,通过计算得到了各工作压力点下击穿电压值的概率分布函数,为蒸发冷却变压器绝缘结构的设计提供了参考。

Experimental research of AC breakdown voltage of evaporative coolant under boiled two-phase-flow condition

As some fluorocarbons have the nonflammability and high electrical strength,they could be used not only as coolant,but also as insulating materials in evaporative cooling transformers and other electrical apparatuses,which will make transformers be nonflammable and non-explosive,safe and reliable,economical and efficient,environmental friendly.In order to obtain the AC breakdown voltage of evaporative coolant under boiled two-phase-flow condition,where the fluorocarbons in application are used as insulating materials,a special experimental equipment was designed and fabricated according to the related national standards. Using a plane-plane electrode with a gap length of 3 mm,the test was carried out in conditions under different pressures.The statistical analysis of the data demonstrated that both of the Weibull and Normal distribution match the result quite well,and provided probability distributions of the breakdown voltage under corresponding pressures.The result also offered plotted relation curve of the breakdown voltage with working pressure of boiled two-phase-flow condition,which is important reference to the insulation structural design of the evaporative cooling transformer.