Surface charge accumulation on the spacers is one of the key issues restraining the development of HVDC GIS/GIL. The precise measurement of surface charge properties provides the basis for further study of the surface charge transport mechanism as well as the charge-induced flashover mechanism under DC voltage. In this study, the authors discuss their perspective on the current status, development needs and potential developing orientation of surface charge characterisation techniques. Different surface potential measurement methods and charge inversion algorithms are reviewed regarding the previous studies and future research needs. Drawbacks and outlooks of surface charge measurement techniques are also discussed with the background of laboratory experiment results and on-site measurements. It is hopefully that this study can serve as a useful guide reference for researchers within the same research field. More importantly, it is authors’ hope that this study can inspire some novel ideas for readers into developing of more accurate and scientific interface charge characterisation techniques.

中文翻译：

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HVDC GIS / GIL绝缘子的气固界面电荷表征技术

间隔物上的表面电荷积累是制约HVDC GIS / GIL发展的关键问题之一。表面电荷特性的精确测量为进一步研究表面电荷传输机制以及直流电压下电荷诱导的闪络机制提供了基础。在这项研究中，作者讨论了他们对表面电荷表征技术的现状，发展需求和潜在发展方向的看法。关于先前的研究和未来的研究需求，综述了不同的表面电势测量方法和电荷反演算法。在实验室实验结果和现场测量的背景下，还讨论了表面电荷测量技术的缺点和前景。希望这项研究可以为同一研究领域的研究人员提供有用的指导参考。更重要的是，作者希望这项研究能够为读者提供一些新颖的想法，以开发更准确，更科学的界面电荷表征技术。