| Patent application number | Description | Published |
|---|
| 20090039866 | Fiber-Optic Current Sensor With Polarimetric Detection Scheme - The current in a conductor is measured by exploiting the Faraday effect in a sensing fiber. The light returning from the sensing fiber is split into at least two parts, at least one of which is analyzed by a first circular analyzer for generating a first signal. A second part may e.g. be analyzed by a second circular analyzer, and a third part may be analyzed by a linear analyzer. By combining the signals obtained in this way, the current induced phase delay in the returning light can be measured efficiently and accurately. | 02-12-2009 |
| 20090097796 | Fiber-Optic Current Sensor With Sum Detection - To measure a sum of electrical currents in different conductors, light is led in an optical sensing fiber around all the conductors. The sensing fiber can be wound around the conductors in a single loop or in several individual loops. Interspersed polarization maintaining fibers and retarders can be used to transfer the light between individual loops for preventing undesired signals from stray magnetic fields. The method has high accuracy is particularly suited for measuring large currents that sum up to zero. | 04-16-2009 |
| 20090289617 | OPTICAL VOLTAGE SENSOR - A voltage sensor includes two optical sensing fibers and a control unit. The sensing fibers carry a first mode of light and a second mode of light, which are orthogonally polarized, with a birefringence between the two modes depending on the electric voltage to be measured. The control unit is configured to generate light for the two modes in the sensing element and to measure the phase delay suffered between the two modes. A 45° Faraday rotator is arranged between the control unit and the sensing fibers. The Faraday rotator allows the behavior and functionality of the sensing fibers and their associated components to be converted to those of a magneto-optical current sensors with polarization-rotated reflection, which in turn allows use of advanced measuring techniques developed for optical gyroscopes and current sensors. | 11-26-2009 |
| 20090290165 | OPTICAL HIGH VOLTAGE SENSOR - An electro-optical high-voltage sensor includes a waveguiding sensing fiber of an electro-optical material. The electrical field of the voltage to be measured is substantially parallel to the longitudinal axis of the sensing fiber. The sensing fiber carries two orthogonally polarized light waves, with the applied field affecting the birefringence between the waves. Using an electro-optical waveguiding fiber in this configuration allows the voltage between two widely spaced points to be accurately measured. | 11-26-2009 |
| 20100108870 | PRESSURE SENSOR - A pressure sensor is disclosed with at least one pressure sensing element, the pressure induced changes in the optical properties of which are evaluated by illumination with at least one light source. The pressure sensor can include at least two semiconductor-based pressure sensing elements located in individual pressure chambers, which sensing elements are located essentially adjacent to each other. The sensing elements can be irradiated with the same light source, wherein the light transmitted through the sensing elements is detected using at least two corresponding detectors, and wherein the differential pressure in the two pressure chambers is evaluated based on the output of these detectors. | 05-06-2010 |
| 20100180686 | PRESSURE SENSOR - A pressure sensor is disclosed wherein pressure induced changes in birefringent properties of an optical sensing element are read out by transmission of at least one light beam. The pressure sensor can include at least one single-material transparent body which is subjected to at least two different pressures (p | 07-22-2010 |
| 20110050207 | HIGH VOLTAGE MEASUREMENT DEVICE USING POLED FIBERS - Two transversely poled fibers are disclosed which can be wound around a holder with their poling directions being anti-parallel. A coupling exchanges the polarization directions of the modes of the fibers. Thermally and mechanically caused birefringence changes can thereby be substantially cancelled, while electrical field induced birefringence changes can be added, to provide a more robust high voltage measuring device. | 03-03-2011 |
| 20110072858 | METHOD FOR MANUFACTURING A FIBER OPTIC CURRENT SENSOR WITH INHERENT TEMPERATURE COMPENSATION OF THE FARADAY EFFECT - A method is provided for tuning the fiber optic retarder of a fiber optic current sensor towards a desired temperature dependence, the sensing fiber is exposed to a magnetic field or corresponding electric current and the sensor signal as well as the signal's dependence on the retarder temperature are measured. From this initial sensor signal and its temperature dependence, a target sensor signal can be determined, at which the dependence on the retarder temperature equals a desired value. Then, the retarder is thermally treated until the sensor signal reaches the target value. The method obviates the need for repetitively measuring the temperature dependence during the tuning process. | 03-31-2011 |
| 20110122654 | HIGH VOLTAGE AC/DC OR DC/AC CONVERTER STATION WITH FIBER-OPTIC CURRENT SENSOR - DC current in a high voltage AC/DC or DC/AC converter station can be measured via the Faraday effect in one or more loops of an optical sensing fiber located at the base of a bushing extending through a wall of the hall. This arrangement can exploit the base of the bushing being at ground potential, which can simplify mounting work and maintenance. | 05-26-2011 |
| 20110128655 | GENERATOR CIRCUIT BREAKER WITH FIBER-OPTIC CURRENT SENSOR - The current in a generator circuit breaker is measured using the Faraday effect of an optical sensing fiber looped around the breaker's conductor. The sensing fiber is arranged in a sensing strip, which can be mounted to the enclosure of the generator circuit breaker or to the conductor. Exemplary embodiments can have a wide measuring range and can easily be fitted to new or existing generator circuit breakers. | 06-02-2011 |
| 20110147346 | GAS-INSULATED SWITCHGEAR DEVICE WITH OPTICAL CURRENT SENSOR - An exemplary gas-insulated switchgear device is disclosed which includes a current sensor and a voltage sensor located at a partition insulator. The current sensor can include a magneto-optical fiber on a flexible carrier strip and can be manufactured separately for being easily mounted to an assembled switchgear device. The current sensor can include an electro-optical fiber extending radially into the partition insulator and whose ends are embedded in recesses in the bus bar as well as in the metal embracing of the partition insulator for accurately integrating the voltage. | 06-23-2011 |
