特高压换流变压器油纸绝缘交直流击穿特性及选型

Breakdown Characteristics of Oil-Paper Insulation in UHVDC Converter Transformer Under AC/DC Voltage and Its Selection of Oil and Paper

作为特高压直流系统的核心设备,特高压换流变压器的国产化对我国特高压直流技术的发展具有重要的推动作用。针对特高压换流变压器的实际运行工况,基于不同油纸组合交直流击穿特性,对其油纸选型进行研究。试验结果表明：绝缘油的击穿电压随交流分量的降低而缓慢下降;油纸绝缘的击穿场强随着交流分量的降低而快速上升;油纸绝缘的性能主要由绝缘纸决定,绝缘油对油纸绝缘强度影响较小。从特高压换流变压器网侧与阀侧出发,同时考虑交流、直流电压在油纸复合绝缘中的分布特点,分析油纸选型需要考虑的因素,根据实验结果,最终得到KI-50X绝缘油与魏德曼DPE绝缘纸为最佳油纸组合。研究结果可为特高压换流变压器的制造提供相关数据参考。

As the core equipment of UHVDC system, the UHVDC converter transformer of home manufacture will be significant to the development of UHVDC technology. According the complicated operation condition of UHVDC converter transformer and the compound voltage breakdown characteristics of different oil-paper combinations, this article researches the selection work of oil and paper. The results show that the breakdown voltage of oil declines smoothly with the decrease of AC voltage components, while the breakdown strength of oil-impregnated paper increases rapidly and the insulation performance of oil-paper is mainly decided by the paper instead of oil. Meanwhile, consider the distribution characteristics of AC and DC voltage in the oil-paper insulation and based on the valve and line side of UHVDC converter transformer, this paper analyzes the factors which will influence the selection work. Finally, according the results that KI-50 X oil and DPE paper are the best choice. In a word, this paper can provide some relevant reference dates to the manufacture of UHVDC converter transformer.