Abstract: A current sensor is provided including a Rogowski coil in an assembly that is easily positioned about a conductor, e.g. without cutting the line or deenergizing the line. In one arrangement, the Rogowski coil is formed about a split helical structure such that the ends of the Rogowski coil are not coincident. While this does introduce a small error in the current measurement, this small error is easily correctable by calibration and/or application software. The current sensor includes suitable insulation such that it can be placed about energized, high-voltage lines.

Abstract: A magneto-striction based, passive optical current sensor is provided that is located at high voltage and communicates to ground level via an optical fiber. The optical current sensor includes a ferromagnetic core, a modulator of magnetostrictive material, e.g. Terfenol-D in a preferred embodiment, that responds to the magnetic field, and two or more matched fiber Bragg gratings that convert this response into a wavelength modulated optical signal that is transmitted via an optical fiber to ground level electronics. To linearize the output of the optical current sensor, the optical sensor includes arrangements to provide both mechanical and magnetic bias to the modulator.