冲击电压下不同温度油中空间电荷迁移对电场分布影响

冲击电压下油中空间电场分布对于变压器内部绝缘优化设计至关重要,现有设计方法没有考虑温度和空间电荷迁移对电场的影响。为了研究温度对空间电荷迁移特性的影响,搭建温度可控的冲击电压下油中电场测量平台,测量雷电冲击电压下25℃、50℃、60℃均匀电场的油中空间电场分布,分析空间电荷对油中电场的影响。实验结果表明:随着温度的增加,60℃时油中场强峰值比25℃时下降了5.2%;50℃时油中场强分布在0.60μs时提前达到稳定阶段。温度升高后,电子漂移速度最大是25℃下的1.8倍,迁移率最大是25℃下的2.0倍,温度升高引起电子迁移率、漂移速度的增加导致了上述现象。该文研究结果为变压器绝缘优化设计提供了实验依据。

Effect of Space Charge Migration on Electric Field Distribution at Different Temperature in Oil Under Impulse Voltage

It is important for optimization design of transformer insulation that the spatial electric field distributes in the oil under the impulse voltage. Existing design methods do not take into account temperature and space charge migration effects. In order to study the effect of temperature on the space charge migration characteristics in the oil, an electric field measurement platform under impulse voltage was built, the temperature of the measuring platform can be controlled. The spatial electric field distribution in the oil with uniform electric field at 25℃, 50℃ and 60 ℃ under lightning impulse voltage was measured. The results show that as the temperature increases, the peak electric field strength at 60 ℃ has decreased by 5.2% compared with it at 25 ℃, the field strength distribution in the oil reaches the stable stage at 0.60 μs under 50℃, the maximum electron drift velocity and mobility is 1.8 and 2.0 times at 25 ℃. The increase in electron mobility and drift velocity caused by temperature primarily generates the above phenomenon. The results of this paper provide experimental basis for transformer insulation optimization design.