A Unified Sensor Platform for Investigating Corona Effects on Overhead Lines

Outdoor long-term continuous measurements of overhead conductor corona are needed to better plan high-voltage power grids. Most of the time, only single aspects of corona are being measured over short periods of time in controlled environments using complex and expensive sensors. This article presents a single unified wireless sensor platform to reliably measure three distinct corona-related quantities on high-voltage lines, namely, the corona current through the line, the ground-level electric field, and the ground-level ion current density. The platform is a distributed, cost-effective, low-power Internet of Things (IoT) system that enables outdoor measurements of lines exposed to real weather overextended periods of time allowing to highlight correlations across seasons. With example measurements, the importance of having heterogeneous sensors measuring different corona effects in a unified way is demonstrated. The corona current sensor is shown to operate at up to hundreds of kV while still providing an accuracy of 83 nA and an average power consumption of 1 mW. Corona effects, collected every 4 s with a sampling frequency up to 1 kHz, make it possible to visualize correlations with environmental parameters, such as humidity, precipitation, and wind speed in novel ways through onboard processing of the collected data.