Design of a 3D Magnetic Field Sensor for Live-Line Safety Operations

To address the safety monitoring requirements in live-line operations under complex electromagnetic environments, this paper proposes a three-dimensional (3D) magnetic field sensor design based on multi-turn coils. By establishing an equivalent circuit model and optimizing the magnetic core structure, an orthogonally configured 3D sensor architecture is developed. A signal conditioning module integrating impedance conversion, low-pass filtering, inverting amplification, precision rectification, and voltage division buffering circuits is implemented to enhance the signal-to-noise ratio of weak signals. Simulations and experimental results demonstrate that the sensor can detect magnetic field strength within a spatial range of 0.5m at 0-200A power frequency current, with a measurement error of less than 10%. This provides a miniaturized and low-cost solution for safety warning of live working.