Remote sensing of voltage using optical assessment of corona

The measurement of voltage in a high voltage substation is relatively costly. It may be surmised that a method of remotely sensing the voltage in a substation would, overall, be cheaper since insulation would not be required. Other researchers have considered this strategy and have developed designs using electric field based sensors. To date, no consideration has been made of the possibility of voltage measurement by assessing the presence of corona on high voltage plant, made possible by advances in imaging technology. This paper describes the early results of a project investigating corona based voltage measurement. Initial studies, investigating DC voltage measurement, are reported including typical accuracy, spectral characteristics and equipment requirements. The project is now considering the issue of AC voltage measurement and early research into this is reported. The paper concludes with a discussion of the prospects of this technique for substation applications.