5 results about "Optical current transducer" patented technology

The present application relates to a kind of stress line birefringence compensation method of optical current sensor, the optical current sensor includes laser source, polarizer, magneto-optical film, nanometer ring-shaped radial polarization grating, image beam and CMOS area array camera sequentially arranged in same optical path, the method includes the following steps: utilize laser source to emit light signal, under the action of current to be measured, the output signal of optical current sensor is superposed with Faraday magnetic rotatory angle θ And stress line birefringence δ, form synchronous rotating annular light spot;Determine the zero-crossing moment of the measured alternating current, the rotation angle of corresponding annular light spot is stress line birefringence δ at zero-crossing moment by CMOS area array camera and record;Based on the stress line birefringence δ of record, utilize model-free adaptive iterative learning method to predict the stress line birefringence δ of future time, and according to the prediction result, the output signal of optical current sensor is compensated.

The application discloses a kind of independent double strip optical current sensor and its anti outside temperature fluctuation interference method belonging to the field of intelligent measurement and sensing technology of electric power system.The sensor includes mutually connected sensing unit and signal processing unit, wherein the output end of multi-frequency modal decoupling signal processing device is connected with the input end of double strip optical current sensor signal processing device, the output end of double strip optical current sensor signal processing device is connected with the input end of measurement signal output device;Sensing unit is provided with double strip sensing unit main structure including measurement sensing optical path structure and temperature compensation sensing optical path structure, the vertical distance of the midpoint of measurement sensing optical path structure and temperature compensation sensing optical path structure to the current to be measured is equal.The application can realize the measurement function of temperature resistance while ensuring the long-term operation stability of single straight-through optical path type optical current sensor, and the advantages of simple structure.

This invention discloses a single-path dual-channel optical current sensor device and a self-compensation testing method. The method and device can achieve four-AD sampling and bidirectional demodulation of the same current sensor optical path, and automatically compensate for temperature-induced errors. The method includes an optical path unit, a circuit unit, and a data processing unit. The optical path uses a coupler to split the light source into two beams. Utilizing the symmetry of the sensing optical path, dual-channel demodulation is achieved, and an isolator is used to achieve unidirectional light output, avoiding bidirectional light interference with the light source and signal power. Each channel uses dual-AD differential demodulation, and a beam splitter ensures that the differential signals are of equal magnitude. Coupler 2 is used to monitor the light source power. The circuit unit includes a light source driver, temperature control and drive closed-loop control, a signal filtering and amplification unit, and a DSP or microcontroller for AD acquisition and signal processing. The data processing unit includes a current signal demodulation algorithm and a self-compensation method.

An optical fiber break detection method includes: acquiring multiple current sampling data of a photodiode in an optical current transducer; respectively performing wavelet transform on the multiple current sampling data to obtain a detail coefficient corresponding to each of the current sampling data; and determining an on / off state of an optical fiber in the optical current transducer according to the detail coefficients corresponding to the multiple current sampling data. This solution achieves the detection of an optical fiber break within a relatively short time, thereby reducing the occurrence of malfunction in a relay protection apparatus in case that an optical fiber break occurs. An apparatus and the relay protection apparatus are configured for implementing the method.

This invention relates to an AC zero-crossing compensation method for stress line birefringence in an optical current sensor. The optical current sensor includes a laser source, a polarizer, a magneto-optical thin film, and a radial polarization grating arranged sequentially on the same optical path. The method includes the following steps: emitting an optical signal using the laser source, which passes sequentially through the polarizer, the magneto-optical thin film, and the radial polarization grating. Under the influence of the current to be measured, the output signal is superimposed with the Faraday magnetostrictive rotation angle α and the stress line birefringence γ, forming a translated strip-shaped light spot; locating the position of the strip-shaped light spot using a position-sensitive detector and measuring the rotation angle of the polarization plane of the linearly polarized light; detecting the AC zero-crossing point of the current to be measured, and acquiring the rotation angle of the polarization plane measured by the position-sensitive detector at the zero-crossing point as the stress line birefringence γ; and compensating the output signal of the optical current sensor using the acquired stress line birefringence γ.