The goal of this project is to design a non-intrusive meter that can accurately measure the current in a standard electric power cable such as an extension cord or lamp cord by monitoring the vector magnetic field around it. Standard ’non-intrusive’ current meters either require the conductors to be separated and a single conductor inserted through a magnetic loop-based current transformer, or use an external magnetic field sensor and knowledge of the relative geometry of the wires and sensor. The net flux surrounding a standard power cable is zero because there is no net current in the cable inside. Locally, however, the two current-carrying wires produce a magnetic dipole. In this work, we are designing a sensor that uses multiple vector magnetic field measurements and intelligent algorithms to measure the current flowing in a power cable with no knowledge of the conductor geometry. The sensor will be a PCB-based solution that is easily movable between load devices, uses commercial sensors, includes low-power wireless communication, and can measure currents down to approximately 10 mA RMS.
Project end date: 07/15/16