A Novel Non-contact Measurement Method for Current Positioning Based on Magnetic Sensors

With the intelligent and distributed development of the power grid, the demand for the security of power systems is increasing. As an essential part of energy transportation in power systems, transmission lines have arc sags and wind-induced swings that can lead to serious safety incidents, so more and more researchers are studying the spatial condition monitoring of transmission lines. The existing methods usually use intrusive sensors, such as temperature sensors, or need photographic image analysis. Nevertheless, the intrusive sensors may increase safety risk, and the image analysis can be affected by extreme weather conditions. This paper proposes a novel non-contact method for current measurement and spatial positioning based on magnetic field sensors. In this method, two sensors are combined as a probe. By analyzing the magnetic field at different distances, the space position of the conductor and the target current can be calculated. Since the measurement results of this method are unstable when the target current is close to 0, this paper proposes an optimized method by using a limiter and digital low-pass filter to process the distance values, which effectively improves the measurement stability and accuracy. In experiments, the average error of distance is about 1%, and the error of the current RMS is about 2%.