The invention enables an optical voltage sensor, comprising a piezoelectric actuator mechanically coupled to an optical strain sensor (such as a fibre Bragg grating), to withstand lightning impulses, the effects of which would otherwise be harmful or destructive to the piezoelectric actuator and/or other sensitive components. As such, the optical voltage sensor, comprised within a photonic voltage transducer which also comprises a lightning impulse attenuator, is able to comply with relevant standards and be used for applications in power networks and exposed to the highest voltages for equipment.

An optical fiber winding for measuring current circulating through a conductor. The optical fiber winding includes a first helically wound optical fiber cable and a second helically wound optical fiber cable. The first helically wound optical fiber cable is twisted about its longitudinal axis in a first twist direction, and the second helically wound optical fiber cable is twisted about its longitudinal axis in a second twist direction, the first twist direction being opposite the second twist direction. Each of the first and second helically wound optical fiber cables making contact with one another at multiple locations along their length. Due to the first and second helically wound optical fiber cables making contact with one another and being twisted in opposite directions, counteracting forces exist where the first and second helically wound optical fiber cables contact one another to resist an untwisting.

An optical fiber winding for measuring current circulating through a conductor. The optical fiber winding includes a first helically wound optical fiber cable and a second helically wound optical fiber cable. The first helically wound optical fiber cable is twisted about its longitudinal axis in a first twist direction, and the second helically wound optical fiber cable is twisted about its longitudinal axis in a second twist direction, the first twist direction being opposite the second twist direction. Each of the first and second helically wound optical fiber cables making contact with one another at multiple locations along their length. Due to the first and second helically wound optical fiber cables making contact with one another and being twisted in opposite directions, counteracting forces exist where the first and second helically wound optical fiber cables contact one another to resist an untwisting.

The following relates generally to optical voltage sensing, and in particular to optical voltage sensing of power grids and of a subject body. For example, some embodiments include an optical resonator comprising: (i) a top electrode layer, (ii) a piezoelectric layer, and (iii) a substrate. A light source may illuminate the optical resonator of the voltage sensor with light comprising an incident optical power at an input wavelength, where the input wavelength is offset from a resonant wavelength of the optical resonator by a baseline voltage. The applied voltage may then be measured by measuring a reflected or transmitted light power.

The present disclosure relates to the technical field of current sensors, and provides a fiber-optic current transformer based on nitrogen-vacancy (NV) centers in diamond, and a measurement method. The fiber-optic current transformer based on NV centers in diamond includes a device for laser light excitation and reflected light reception and analysis, a diamond NV center probe, a magnetic concentrator, and a microwave excitation device. The fiber-optic current transformer based on NV centers in diamond includes three measurement methods: an all-optical measurement method, a non-all-optical measurement method, and a measurement method combining the all-optical measurement method and the non-all-optical measurement method. A sensor in the present disclosure has advantages of a simple structure, strong practicability, resistance to external interference, and strong robustness.

A wireless tracking device includes circuit components, a battery, and a circuit connecting the circuit components and the battery. The circuit components include a first wireless communication system, a processor, a memory or storage, and a first sensor operable to measure conditions of the wireless tracking device. The wireless tracking device is configured to attach to an overhead electrical line and detect failure events that are experienced by the overhead electrical line based on sensor data monitored by the wireless tracking device.

A measuring device measures an electrical current and contains a light source for generating a polarized primary light signal for feeding into a Faraday sensor unit, and a detector for detecting a secondary light signal provided by the Faraday sensor unit and polarization-altered in relation to the primary light signal. An optical-electrical compensation element, by which the polarization alteration of the secondary light signal can be compensated via an opposite polarization alteration, and a measurement signal, according to the opposite polarization alteration, for the electrical current can be deduced. A method for measuring an electrical current by use of the measuring device is further disclosed.

The voltage measuring device includes: a light source; a polarizer polarizing light emitted from the light source; a grounded conductor provided apart from a high-voltage conductor; a crystal end face electrode being out of contact with the grounded conductor and the high-voltage conductor; a Pockels cell transmitting light from the polarizer; an analyzer transmitting light reflected by the Pockels cell; a photodetector detecting light emitted from the analyzer; an intra-crystal electric field measurement unit converting voltage output by the photodetector into intra-crystal electric field; a bias electrode being out of contact with the crystal end face electrode; a bias supply; a bias supply control unit controlling the bias supply to keep internal electric field of the Pockels cell at zero; and a measurement voltage calculation unit obtaining voltage of the high-voltage conductor based on results output by the intra-crystal electric field measurement unit and the bias supply control unit.

A method for distinguishing an arc from a luminous gas at least containing metal vapor includes sensing light in a monitoring region and determining a first intensity I.sub.λ1 of the sensed light at a first wavelength λ1 and a second intensity I.sub.λ2 of the sensed light at a second, greater wavelength λ2. The ratio I.sub.λ1/I.sub.λ2 between the first intensity I.sub.λ1 and the second intensity I.sub.λ2 is determined. The sensed light is associated with an arc if said ratio I.sub.λ1/I.sub.λ2 is greater than a specifiable first threshold value and/or with a luminous gas at least containing metal vapor if said ratio I.sub.λ1/I.sub.λ2 is less than a specifiable second threshold value.

An electric field sensing system, in some embodiments, comprises a magnetic shield, an optical magnetometer shielded from external magnetic fields by the magnetic shield, a conductive coil proximate to the optical magnetometer, and first and second electrodes coupled to opposite ends of the coil. The electrodes are disposed outside of the magnetic shield. The conductive coil generates a magnetic field within the optical magnetometer when electrical current passes through the conductive coil.