Development of a New Low-Cost and Reliable Core-Less Current Probe for Conductor With Reduced Access

A new coreless non-intrusive current probe is presented in this paper. Most of the existing current sensors require 360° access to the wire, while the proposed probe accurately measures the current even if the access to the wire is limited to a small angle. Another new feature of the probe is that its output is not sensitive to the variation in the gap between the wire and the probe, which is a major advantage as it helps to provide reliable measurement over time. The proposed probe employs two sets of high sensitive and lightweight Hall effect or giant magneto-resistance-based sensors. Results from the experimental studies conducted showed that the proposed configuration is insensitive to the variation in the gap between the wire and the probe. This feature ensures that the output is independent of the insulation thickness, vibration, thermal expansion, etc. Two prototypes of the proposed probes have been developed and tested. The results obtained established the feasibility of the proposed low-cost current sensor.