Abstract: A stress control apparatus for managing effects caused by electrical stress in a high voltage environment, and methods of manufacturing the apparatus. A dielectric tube with a central bore coated with a conductive material has an outer conductive coating on a lower section that is grounded. The central bore carries a high voltage potential from a current-carrying conductor. The grounded coating transitions to the exposed outer dielectric surface along a gradually tapered transition. A conductive insert connects to the central bore and forms an electric field in a space between the insert and the grounded coating. When coated with an epoxy and inserted into the central bore, the insert forms a small gap between an outer surface of the insert and part of the central bore, such that there is no zero potential difference in the gap. Any epoxy that oozes out during insertion will collect in the gap.

Abstract: An optical sensor that senses current by directing polarized light across an airgap that is orthogonal to a direction of current running through a conductor. The sensor includes a prism having a high Verdet constant for high sensitivity to magnetic fields, which cause an angle of polarization of the polarized light to be rotated as an indication of the magnitude of current. A polarizing beamsplitter having a low Verdet constant is mounted to the prism so that incoming light that is traveling in a direction orthogonal to the magnetic field being sensed across the airgap is insensitive to unwanted magnetic fields produced by nearby conductors. The distance the light travels in this orthogonal direction is minimized, reducing the overall volume of the sensor, making a compact sensor highly sensitive to magnetic fields of interest, largely insensitive to unwanted magnetic fields, and having a very high dynamic range for sensing current.

Abstract: Structure is provided for controlling the electrical stress on one or more optical fibers in a high voltage environment.

Abstract: A method of measuring a current of a current carrying cable teaches the first step of providing an optical sensor assembly comprising a base unit, and an optical current sensor mounted on the base unit for transmitting a beam of polarized electromagnetic radiation to an optical fiber. A light detector is also provided having a first channel that operably connecting the light detector to an analog to digital converter through a programmable gain amplifier, a second channel that operably connects the light detector directly to the analog to digital converter, and a processor operably connected to the analog to digital converter. The optical sensor assembly is mounted adjacent the current carrying cable, and the fiber optic is operably connected to a light detector. A plurality of factors are then evaluated from rotation information from the light detector, by using the first and second channels for analog to digital conversion operably connected with the processor.