摘要
为研究叠加电场作用下油纸绝缘的油流带电特性,在实验室搭建了同轴圆柱电极结构的油纸绝缘模型,利用密闭油循环系统开展了叠加电场下油流带电的试验研究,并探讨了外施电压幅值、直流分量比例和油流速度对油流带电的影响。试验结果表明,流速和外施电压幅值对冲流电流的影响与温度有关。在低温下冲流电流随流速和外施电压幅值线性增加,提高直流分量比例会促进冲流电流;在高温下冲流电流随流速指数增加,随外施电压幅值提高出现峰值,峰值电压随直流分量比例提高而下降。理论分析表明:较低温度下油中冲流电流大小取决于纸中负离子的迁移和扩散速度;而在较高温度下该冲流电流取决于油流剥离正离子的速度和外电极处电荷泄放的速率;温度通过影响绝缘中离子迁移速度和电场分布而影响油流带电特性。
In order to investigate the flow electrification characteristics of oil-paper insulation under the AC superimposed DC electric field, an oil-paper tube model with concentric cylindrical electrode geometry was built in laboratory. Experiment study on flow electrification under AC superimposed DC electric field was carried out with the closed oil circulating system, and the influence of voltage amplitude, DC component ratio and oil flow velocity on flow electrification was discussed. The experiment results show that the influences of oil flow velocity and the amplitude of applied voltage on streaming currents are related to temperature. At low temperature, the streaming current increases linearly with flow velocity and amplitude of applied voltage, and the increase of the DC component ratio can enhance the streaming current. At high temperature, the streaming current increases exponentially with flow velocity and shows peak effect with amplitude of applied voltage. The peak point voltage decreases with the DC component ratio. The theoretical analysis demonstrates that the streaming current depends on migration and diffusion rate of the negative ion in paper at low temperature. However, at high temperature, it is related to the stripped rate of positive ion by oil flow and the charge leakage rate at the outer electrode. The temperature can influence the flow electrification characteristics by affecting the ions migration speed and the electric field distribution in the insulation.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2014年第15期2502-2510,共9页
Proceedings of the CSEE
基金
国家自然科学基金项目(51277047)
黑龙江省杰出青年基金资助项目(JC2010-09)~~
关键词
油纸绝缘
交直流叠加电场
油流带电
换流变压器
离子迁移
oil-paper insulation
AC superimposed DC electric field
flow electrification
converter transformer
ion migration
