Abb Research Ltd.

Abb Power Grids Switzerland Ag

Abb Schweiz Ag

Hitachi Energy Ltd

Abb T&d Technology Ltd.

Philippe Gabus

Klaus Bohnert

Andreas Frank

Hubert Brandle

Hubert Braendle

Hubert Brändle

Georg Müller

Xun Gu

Costante Piazza

Jiri Talir

Hubert Br&auml;ndle

Robert Wueest

Roberto Cameroni

Jadran Kostovic

Juergen Nehring

Emiliano Centenaro

The invention relates to a spliced optical fiber comprising a first and second polarization-maintaining optical fiber connected at ends by splicing; to fiber optic current sensors; and to a method for protecting the spliced optical fiber against mechanical stress and/or humidity. A protection tube is arranged around the spliced optical fiber in a splice section of the spliced optical fiber. A first and second end of the protection tube is sealed to the spliced optical fiber by first and second sealing arrangement for protecting the splice.

Spliced optical fiber with splice protection, current sensor with such spliced optical fiber and method for protecting a spliced optical fiber

A fiber-optic current sensor includes an opto-electronics module, a sensor head and a connecting fiber connecting the opto-electronics module to the sensor head. The sensor includes a first and a second beam splitter, between which the measuring light runs in two branches. One fiber connector is arranged in each branch, for connecting a cable assembly to the opto-electronics module. The optical path lengths between the two connectors and the second beam splitter are different, such that light waves cross-coupled into an orthogonal polarization mode due to angular misalignment of the connectors become incoherent with the non-cross-coupled waves returning from the sensor head.

Fiber-optic current sensor with tolerance to connector misalignment

A fiber optic sensor and related method are described, with the sensor including a cross-coupling element in the optical path between a polarizing element and a sensing element, but separated from the sensing element itself; with the cross-coupling element generating a defined cross-coupling between the two orthogonal polarization states of the fundamental mode of a polarization maintaining fiber guiding light from the light source to the sensing element thus introducing a wavelength-dependent or temperature-dependent sensor signal shift to balance wavelength-dependent or temperature-dependent signal shifts due to other elements of the sensor, particularly signal shifts due to the wavelength dependence of the Faraday effect or the electro-optic effect constant.

Fiber-optic sensor and method

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.

Method for manufacturing a fiber optic current sensor with inherent temperature compensation of the faraday effect

A fiber-optic sensor head is disclosed for an optical current or magnetic-field sensor which can have an optical fiber which includes a magnetooptically active sensor fiber which is optically connected to at least one polarization-defining element. The sensor fiber can be arranged in a magnetic field to be measured or around a conductor carrying current to be measured and can be in the form of a coil, with the coil defining a coil plane (A) with a surface normal (N), and with the at least one polarization-defining element having a marked axis (f). The sensor head can be flexible in the area of the sensor fiber, and an adjustment means can be provided for adjustment of a predeterminable angle &#x3b2; between the marked axis,(f) and the surface normal (N) or for adjustment of predeterminable angles &#x3b2;, &#x3b2;' between the marked axes (f) and the surface normal (N).

Fiber-optic sensor coil and current or magnetic-field sensor

A high-voltage component, having a first end and a second end, whereby the first end is on a high-voltage potential with respect to the second end. An insulating part, is arranged between the first end and the second end, and an optical fiber is integrated in the high-voltage component and extends from the first end to the second end. A capillary extends from the first end to the second end and is arranged within the insulating part. The inside diameter of the capillary exceeds the outside diameter of the fiber, and the fiber is arranged within the capillary. The capillary includes a protective medium to achieve a dielectric strength in the capillary, which dielectric strength is suitable for the operating conditions.

High-voltage component with optical fiber and method for producing it

The fiber-optic sensor head () for a current or magnetic field sensor comprises an optical fiber which contains a magnetooptically active sensor fiber () and at least one polarization-maintaining supply fiber (), which are optically connected, with the sensor fiber () having its fiber protective sheath removed. The sensor head () furthermore contains a capillary (), in which at least the sensor fiber () is arranged. Furthermore, the sensor head () can be bent in the area of the sensor fiber (), and a friction reducing means () is provided in the capillary (), in order to reduce the friction between the sensor fiber () and the capillary (). The friction reducing means () is advantageously an oil or a dry lubricating means (). The capillary () is advantageously encased by a capillary casing (). The sensor () allows very largely temperature-dependent measurements, is easy to install and allows measurements on large cross-section conductors.

Temperature-stabilized sensor coil and current sensor

The invention relates to a fiberoptic current or magnetic field sensor having a plurality of sensor heads, and to a corresponding measurement method. The sensor has a light source: N&#x2267;2 sensor heads; at least one phase modulation unit; a detector; a control and evaluation unit. The at least one phase modulation unit is connected to at least one of the sensor heads. Lightwaves can be differentially phase-modulated in a non-reciprocal fashion by means of the at least one phase modulation unit. Modulation amplitudes &#x3c6;and modulation frequencies vare selected as a function of modulation-relevant optical path lengths l.

Fiberoptic current sensor having a plurality of sensor heads

A method is described for producing a fiberoptic waveguide with a basic segment ( ) and a phase shift segment ( ), the basic segment ( ) and phase shift segment ( ) having fiber cores (K) of the same form and the fiber cores being aligned at a defined angle (&agr;) to one another. In the method, use is made of an optical fiber ( ) having a fiber core (K) of the abovenamed form, which fiber is twisted at least approximately by the abovenamed defined angle (&agr;) and held fixed in this torsional position. Subsequently, a stress-relief zone ( ) is heated inside the twisted fiber ( ) until the torsion is released inside the stress-relief zone ( ) and the basic segment ( ) is produced on one side of the stress-relief zone ( ) and the phase shift segment ( ) is produced on the other side. In this case, the fixing of the torsional position is maintained until after solidification of the stress-relief zone ( ).

Method for producing a fiberoptic waveguide

A pole of a high- and/or medium-voltage circuit breaker, including an insulating housing, at least one, interruption chamber which is positioned inside the insulating housing and contains at least a moving contact and at least a fixed contact. A device for measuring the electric current flowing through the pole, and a dielectric gas, the particularity of which is the fact that said device for measuring the electric current flowing through the pole includes an optical current sensor arranged within a volume of the pole that is occupied by the dielectric gas.

Pole of a circuit breaker with an integrated optical current sensor

The subject matter of the present invention is a fiber-optic outdoor high-voltage sensor 1. The known sensor principle is based on the fact that a piezoelectric quartz cylinder 3 wound with a glass fiber 4a effects a voltage-proportional fiber strain which is measured interferometrically. According to the invention, a 420 kV outdoor sensor 1 is created by virtue of the fact that several quartz cylinders 3 and electrically conductive spacing elements 5 are arranged in an alternating fashion one behind another and are sealed in a silicone-shielded 17 insulating tube 16 by means of polyurethane 18 or silicone 21. Dividing the high voltage between several spaced, E-field integrating sensor elements 2 permits simple field control and a very high measuring accuracy. In addition, the fiber-optic voltage sensor 1 is distinguished by a low outlay on insulation, compactness and low weight, and can easily be scaled to other voltage levels and be effectively combined with optical current sensors 38.

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Nussbaumen, Switzerland

Philippe Gabus