Practical Challenges of Magnetic Sensors Based on Magnetic Tunnel Junctions for Power Grid Applications

We provide a review of the status and challenges for utilizing magnetic tunneling junction (MTJ) based magnetic sensors for power grid applications. We show that, with both modeling and experimental measurement, an optimized MTJ-based magnetic sensor can be utilized to monitor grid current, especially for individual grid lines. From the perspective of the sensor, the sensitivity, signal-to-noise ratio, and linearity can all meet the needs in the field. Unlike traditional measurements, this measurement can be based on a contactless or “remote” sensing setup, where the sensor is placed away from the grid line. One of the challenges is that a complex topology and multiple grid lines may exist with different current levels. The other challenge is that, with the improved sensing capability provided by these MTJ sensors, a significantly larger amount of data can be collected, so the system bottleneck shifts from sensing to data transfer.