Influence of Electromagnetic Emissions of High Voltage Overhead Lines on GNSS-Components

Abstract

For the monitoring of high voltage overhead lines (HVOL) automated robotic systems increasingly come to use. Regardless of whether this is set to line-crawler technology or aerial platforms, Global Navigation Satellite Systems (GNSS) are used for position determination on all of these robotic systems. In aerial platforms they serve for precise navigation, but also – as with line-crawlers – for georeferencing of discovered defects on the power lines. Compared to conventional applications the increased electric and magnetic emissions in direct vicinity to the HVOL of up to one meter can be regarded as unique and harsh environmental conditions for the GNSS-components like antennas and receivers. To test the functionality and quality of real GNSS-components in realistically reproduced electromagnetic fields in a laboratory environment, test bench setups have been designed to reproduce the field strengths and emissions, in which for this publication a couple of GNSS-receivers have been tested. The focus of this paper is on low-frequent fields with grid-frequency (here 50 Hz) as well as corona-discharges as an example for broadband, high-frequency electromagnetic emissions of HVOL (0.2…20 MHz). The paper describes the conducted tests and compares and discusses the measured results, which are the recorded values for accuracy and availability of position determination, time-to-first-fix (TTFF) and carrier-to-noise-density-ratio (C/N0).