670 / 2022-03-31 12:22:37

Effect of aging under DC electric field on space charge behavior in oil paper insulation with air gap

oil paper insulation,space charge

Effect of aging under DC electric field on space charge behavior in oil paper insulation with air gap

Li Long-fei1, 2, LIU Lei1, 2, ZHANG Ling1, 2, ZHANG Wei-ning3, ZHANG Fei1, 2, ZHU Si-rui4, DU Zhao-guang1, 2, WEN Jin-tao1, 2

 1.State Grid XinJiang Company Limited Electric Power Research Institute  830011;

2. Xinjiang Key Laboratory of Extreme Environment Operation and Testing Technology for Power Transmission ＆ Transformation Equipment 830011  ;

3.State Grid Xinjiang Electric Power Company 830011;

4. State Grid Hubei Electric Power Research Institute，430077 

2278342555@qq.com

Purpose/Aim

The valve side winding of converter transformer works under the comprehensive action of AC voltage, DC voltage, polarity reversal voltage and harmonic voltage. Its electric field environment is very complex, which is very different from ordinary power transformer. In order to reveal the effect of aging on the insulation performance of oil paper with air gap under DC electric field, relevant experiments were carried out on oil paper insulation with air gap at different aging stages under DC electric field, and the space charge distribution characteristics at different aging stages were studied.

Experimental/Modeling methods

Through the experiment, the space charge characteristics of oil paper insulation with air gap in different aging stages were obtained after applying DC electric field to three layers of 0.15mm oil paper insulation with air gap in the middle (as shown in figure a) for 2 hours by electroacoustic pulse method.

Results/discussion

The experimental results show that with the increase of aging time, the space charge in the air gap of oil paper insulation accumulates, and increases with the increase of aging time.

Conclusions

With the increase of aging time, the charge accumulates continuously. The accumulated charge causes electric field distortion. With the increase of aging degree, the electric field distortion increases with time and reduces the initial voltage of partial discharge.

Appendix (Figure, table, image…)

If needed, please include a figure or a table or an image with a caption here.