JPhysD编辑优选:新型环保绝缘气体C4F7N及其混合气体电场敏感性研究

04 1月 2021 gabriels

该研究来自武汉大学电气与自动化学院唐炬教授团队的肖淞副教授研究小组,并与湖南大学、湖北工业大学的同行合作完成。通过实验和计算结果分析发现:含有新型环保绝缘介质C4F7N的混合气体电场敏感性略高于SF6及其混合气体,易在设备内部电场极不均匀区域发生放电。当设备内部出现严重影响电场均匀性的绝缘缺陷或结构设计和制造优化不足时,相对容易发生放电性故障等问题,从而影响电力系统安全可靠运行。因此,对设备制造和维护的要求更高,需引起重视。


文章介绍

The sensitivity of C4F7N to electric field and its influence to environment-friendly insulating gas mixture C4F7N/CO2

肖淞 高兵 庞轩佩 张晓星 李祎 田双双 唐炬 罗毅

第一作者:

  • 肖淞 武汉大学

通讯作者:

  • 高兵 湖南大学
  • 李祎 武汉大学
In this paper, the influence of electric field on C4F7N/CO2 mixture with different gas pressure and mixing ratio are tested, analyzed and compared with SF6 by experiment (Fig.1). According to Fig. 2 and Fig. 3, it can be found that the electric field sensitivity of CO2 is higher than that of pure SF6 after mixing C4F7N, and the sensitivity is obviously improved with the increase of C4F7N content or mixed gas pressure. At the pressure of 0.1MPa or more, the ratio of breakdown voltages in highly non-uniform electric field and quasi-uniform electrical field of C4F7N/CO2 is lower than 1. When the gas pressure was 0.6 MPa and the mixing ratio was 12%, the breakdown voltage in highly non-uniform electric field is even close to half that of quasi-uniform electrical field. It can be predicted that if the mixing ratio or the gas pressure is further increased, the breakdown voltage ratio will continue to decrease, and the difference of the breakdown voltages in the two electric fields further expand. In order to further explain the breakdown characteristics of C4F7N/CO2 mixture under the extremely heterogeneous electric field and verify the effectiveness of the experimental results, this paper theoretically analyses the dielectric insulation strength under different proportions and pressures from the perspective of calculation. (Fig.4)

Fig.1 Experiment platform
Fig. 2 The breakdown characteristics in quasi-uniform electrical field and highly non-uniform electric field
Fig. 3 The ratio of breakdown voltages of different gases in highly non-uniform electric field and quasi-uniform electrical field
Fig.4  Sensitivity of mixed gases to electric field non-uniformity

The electric field sensitivity of CO2 is higher than that of pure SF6 after mixing C4F7N, and the sensitivity is obviously improved with the increase of C4F7N content or mixed gas pressure. It is very easy to discharge in the non-uniform electric field commonly induced by the rough metal surface inside GIE. Its sensitivity is higher than that of SF6 and CO2, which makes equipment more likely to suffer quality problems and affects the security, reliability and power quality of power systems. Therefore, the requirements for equipment manufacturing and maintenance are higher, and it is necessary for related fields to pay enough attention. Future research will be required to study the influence from gap spacing and other shape of electrodes.

研究背景

SF6气体具有优异的绝缘性能和良好的灭弧能力,被大量应用于中高压气体绝缘设备中。《京都议定书》将SF6列为六大温室气体之一。因此,寻找环境友好型气体作为电气设备绝缘介质成为近年来的研究热点。C4F7N及其混合气体因其优良的环保和介电性能而备受关注,国内外专家学者对其绝缘和灭弧性能、分解和恢复特性、生物安全性、材料相容性等开展了大量研究,证实其具备替代SF6应用于中高压气体绝缘电气设备的潜力。然而,现阶段缺乏对该气体电场敏感性的研究和报道,而设备内部绝缘缺陷和结构优化不足可能产生不均匀电场,并极易诱发放电进而导致设备绝缘故障。该研究分析了电场对C4F7N及其混合气体的影响,为设备内部电场设计和缺陷防护提供理论基础。


作者介绍

肖淞,武汉大学电气与自动化学院副教授,博士生导师,中法双博士。近五年来,主持了2项国家自然基金、2项博士后科学基金(含特别资助)等项目;发表了SCI检索论文63篇(第一作者或通讯作者31篇、ESI高被引论文6篇);荣获重庆市科技进步一等奖、贵州省科技进步二等奖和中国产学研合作创新成果二等奖。入选中国科协“青年托举人才工程”和湖北省“楚天学者计划”,获得全国“向上向善好青年”荣誉称号。