Development of a Portable Corona Current Measuring Device for High Voltage Detection in HVDC Systems

Abstract

High voltage direct current (HVdc) detection is essential to ensure the suitability and operation of electrical systems, as well as personal safety. Today there are commercial sensing devices equipped with a safety system that emits audible warnings, but they do not indicate voltage and polarity levels. Likewise, although the scientific literature describes various solutions with satisfactory results, very few of these achievements are found in real-world applications. The purpose of this article is to present a technological alternative based on the study and development of a simple and portable electronic device to enable the detection and quantification of high voltage and polarity in HVdc systems. The principle is based on the detection of corona current by means of an aluminum tip held at a distance of about 5 mm from the energized surface through a radial contact rod. The detected electrical current signal is collected and processed through an electronic system. The performance was analyzed by means of corona discharge models and high voltage experimental tests in real-world conditions. The results demonstrated the satisfactory response of the proposed approach in the detection, quantification, and identification of polarity in a ±600 kV HVdc transmission system, with an error varying from 1.79% to 2.72% compared to theoretical values, as well as its ability to withstand the influence of temperature variations between 18 °C to 29 °C, relative humidity between 56% and 78%, and an atmospheric pressure kept constant at 101.6 kPa. The proposed approach contributes to HVdc monitoring and inspection activities, helping to ensure their operation and suitability.