Real-time current overhead lines load current Monitoring using GMR sensors
We have developed a physical test facility to estimate the overhead line load current using a non-contact GMR magnetic sensor. Two GMR sensor heads were used to measure the overhead power lines’ magnetic field. The off-the-shelf GMR sensors were calibrated to determine the sensitivity, a factor to convert the analog voltages from the sensor to magnetic fields. Alongside the GMR sensor, Hall effect current sensors were installed in the facility to capture the current data, which serves as a reference load current data. A modified mathematical model based on the Biot-Savart theory was the basis for estimating the overhead line current from GMR sensor data. The calculated and measured current from the Hall effect sensor were compared to find the estimation accuracy. Finally, an application was developed using MATLAB program to monitor the measured and estimated magnetic field and load current data in real-time.