Magnetic Field Measurement for Modern Substations

A relatively newer generation of magnetic field sensors has found application in broadband electric current measurement. They are based on the magnetoresistance (MR) effect, remain linear for strong magnetic field stimulus, and can operate at a wide band of frequencies. This chapter explains the study of the effect of sensor size, and then designs a measurement system with small MR sensor head. A single magnetic sensor can be employed for large current measurement when placed in the close vicinity of a conductor. However, the magnetic field is complex in modern substations. Higher sensitivity limits the application of MR sensors in environments with nearby magnetic noise sources. A novel method for a wide range of electric current measurement with tunnel magnetoresistance sensors has been proposed to reduce the effect from an adjacent current‐carrying conductor, which is verified by numerical simulations, finite element analysis of the field, and laboratory experiments in the presence of strong magnetic disturbance.