19 results about "Fiber optic current sensor" patented technology

The invention provides an optical fiber longitudinal differential sampling synchronization error evaluation method and system, and the method comprises the steps: 1, carrying out the timing sampling of a host and a slave at two sides of a line, and circularly recording the serial number and timestamp of each sampling; step 2, the host generates a synchronous benchmark message based on a time synchronization source accessed by the host and pushes the synchronous benchmark message to the slave at regular time; step 3, the slave generates a synchronous benchmark based on the time synchronization source accessed by the slave and the synchronous benchmark message pushed by the host; and step 4, based on the synchronous benchmark, calculating the error of the sampling moments of the host and the slave after each sampling, and performing synchronous error evaluation. According to the method, the synchronization error of the optical fiber differential sampling data of the current ping-pong synchronization can be evaluated by using the time synchronization source in the transformer substation, and the method does not damage the principle that a protection device does not depend on external time synchronization operation. The evaluation algorithm is low in communication resource occupation and small in calculation amount.

The invention relates to the technical field of aluminum electrolysis, and provides an aluminum electrolysis cell damage inversion method based on a machine learning algorithm, and the method comprises the following steps: obtaining the current data of an aluminum electrolysis cell through an optical fiber current sensor, and obtaining the temperature data of the aluminum electrolysis cell; carrying out blanking area division according to a blanking device of the aluminum electrolysis cell; performing regional division on the current data and the temperature data, and performing feature extraction on the current data and the temperature data; establishing a physical information forward model based on a neural network, and performing association mapping on the damage state vector, the current characteristic data and the temperature characteristic data through the physical information forward model; constructing a cathode joint loss function and an anode joint loss function; and respectively carrying out iterative solution on the cathode joint loss function and the anode joint loss function through an optimization algorithm, outputting an optimal damage state vector, and generating a damage space distribution result of the electrolytic cell. According to the invention, online inversion and spatial distribution visualization of the damage states of the anode and the cathode can be realized.

The utility model relates to sensor technical field provides a kind of optical fiber current sensor calibration platform, comprising: bottom, still include: synchronous drive mechanism, set in the top of the bottom. The utility model, by controller control motor start, make its output shaft drive bidirectional screw rod rotate, can make two movable strips synchronous to middle mobile, can synchronous clamping mechanism and limit mechanism move to middle, make external plug and optical fiber current sensor connect, make slide bar along the inside of guide groove slide to one side, make the clamping plate gradually move to optical fiber current sensor, clamping and fixing to optical fiber current sensor, make the ball along the inside of guide frame slide, synchronous drive limit plate to one side moves, will be placed groove two position place shelter, make limit plate to external plug limit, like this, only need to use a motor, i.

The application discloses a closed-loop control direct-current fiber current sensor, which comprises a grating light valve type fiber direct-current current sensor and a polarization interference type fiber temperature sensor; the polarization interference type fiber temperature sensor and the sensing head of the grating light valve type fiber direct-current current sensor are integrated in the same shell; the temperature at the primary sensing head of the grating light valve type fiber direct-current current sensor is measured through the polarization interference type fiber temperature sensor; error correction is carried out according to the measured temperature information; and the influence of the environmental temperature change on the measurement accuracy of the grating light valve type fiber direct-current current sensor is corrected. Meanwhile, the micro-power light control signal source technology is adopted to realize the closed-loop light feedback control of the grating light valve type fiber direct-current current sensor, the measurement linearity of the grating light valve type fiber direct-current current sensor is improved in the closed-loop demodulation algorithm, and the dynamic measurement range is increased.

The application discloses a method for determining a modulation signal of optimal modulation depth of a reflective all-fiber current sensor, and amplitude U of a modulation signal corresponding to the optimal modulation depth H is determined by adjusting amplitude of a modulation signal of a phase modulator PM When the peak-to-peak value of the light power received by the photodetector is maximum and the number of extreme points in one period is 3, the amplitude U of the modulation signal corresponding to the modulation depth H = π rad is obtained PMπ Thus, the electro-optic modulation coefficient k of the phase modulator is determined AP When the optimal modulation depth H o = 1.84 rad, the amplitude of the modulation signal corresponding to the optimal modulation depth is U PMo The method realizes online measurement of the half-wave voltage of the phase modulator, determines the modulation signal corresponding to the optimal modulation depth through the theoretically optimal modulation depth, does not introduce additional devices, and is simple and convenient to operate; and the application is not limited to the reflective all-fiber current sensor, and is suitable for any interference optical path structure which needs to measure the half-wave voltage.

A current measurement method, an optical fiber current sensor system, a medium and a product relate to the field of electrical variable measurement, and the method comprises the following steps: splitting coherent light into a first path of reference light and a second path of sensing light; performing phase modulation on the first path of reference light to generate modulation reference light carrying a phase carrier; the second path of sensing light is guided into two fiber cores of a double-core optical fiber, light output by the two fiber cores of the double-core optical fiber is subjected to spatial beam combination and is coupled into synthesized sensing light, then the synthesized sensing light and the modulation reference light are subjected to coherent superposition, and two paths of interference light signals are obtained; and respectively obtaining a first digital signal sequence and a second digital signal sequence, performing digital signal processing to extract a fundamental component and a frequency multiplication component of a phase carrier, calculating a real-time phase value, and converting the real-time phase value into a current measurement value of the current-carrying conductor to be measured. According to the invention, the current measurement precision can be improved.

The present application relates to the technical field of aluminum electrolysis, and provides an aluminum electrolysis cell damage inversion method based on a machine learning algorithm, comprising the following steps: obtaining current data of an aluminum electrolysis cell through a fiber-optic current sensor, and obtaining temperature data of the aluminum electrolysis cell; performing discharge area division according to a discharger of the aluminum electrolysis cell; performing area division on the current data and the temperature data, and performing feature extraction on the current data and the temperature data; establishing a physical information forward model based on a neural network, and associating and mapping a damage state vector with current feature data and temperature feature data through the physical information forward model; constructing a cathode joint loss function and an anode joint loss function; respectively performing iterative solution on the cathode joint loss function and the anode joint loss function through an optimization algorithm, outputting an optimal damage state vector, and generating a damage space distribution result of the electrolysis cell. The present application can realize online inversion and spatial distribution visualization of anode and cathode damage states.

The invention discloses a current measurement method and device based on a reflection-type optical fiber current sensor, and belongs to the technical field of photoelectricity, and the method comprises the steps: carrying out the first multi-harmonic component extraction of an optical fiber interference signal of a to-be-measured current according to a reference signal before adjustment, and obtaining a first first harmonic component and a first second harmonic component; calculating a first phase offset error, and further generating a phase locking control signal; adjusting the phase of the reference signal according to the phase locking control signal; performing second multi-harmonic component extraction on the optical fiber interference signal according to the adjusted reference phase to obtain a second first harmonic component and a second second harmonic component; and finally, according to the second primary harmonic component and the second secondary harmonic component, calculating the current value of the current to be measured. By implementing the invention, the problem that the reference signal phase cannot be adaptively adjusted in the prior art can be solved, and the accuracy of the current measurement result is improved.

The invention discloses an inclined grating radiation modulation type all-fiber current sensor with dielectric film filtering. The inclined grating radiation modulation type all-fiber current sensor comprises a broadband light source, a 45-degree inclined fiber grating, a lens system, a movable fiber with a dielectric film coating, a fixed fiber, a photoelectric detector and a signal processing unit. The 45-degree inclined fiber bragg grating outputs the S polarization component at a wavelength-dependent radiation angle, and the S polarization component is focused to the end face of a movable optical fiber plated with a dielectric film coating through a lens; the side wall of the movable optical fiber is plated with a permanent magnet alloy layer, the movable optical fiber generates transverse micro-displacement under the action of an alternating magnetic field of current to be measured, and meanwhile, the radiation light receiving efficiency of the movable optical fiber and the coupling efficiency between the movable optical fiber and the fixed optical fiber are modulated; the photoelectric detector detects the light intensity change, and the signal processing unit accurately inverts the current value according to the light intensity change. Compared with the prior art, the current sensor has the advantages of being all-fiber passive, resistant to electromagnetic interference and ambient light interference, good in temperature stability and high in sensitivity, and is suitable for high-precision current detection in complex illumination and electromagnetic environments.

The invention belongs to the field of power equipment on-line monitoring, and particularly provides an active compensation magneto-optical fiber current sensing device and method.The active compensation magneto-optical fiber current sensing device comprises a light source connected with an optical fiber circulator, the optical fiber circulator is connected with a first optical switch, and a port I of the first optical switch is connected with a first input and output port of a temperature reference magneto-optical fiber sensing probe; a port II of the first optical switch is connected with a second input / output port of the magneto-optical fiber sensing probe, a port I of the second optical switch is connected with a first output port of the temperature reference magneto-optical fiber sensing probe, and a port II of the second optical switch is connected with a second output port of the magneto-optical fiber sensing probe; the magneto-optical fiber sensing probe is arranged in the current sensing solenoid, and the current sensing solenoid is connected in series between the tested current units. The temperature stability problem of the magneto-optical fiber current sensor can be solved, and the temperature application range of the magneto-optical current sensor is expanded.

The application discloses a kind of optical fiber current sensors based on multistage cooperative temperature compensation, including optical sensing unit, modulation and switching unit, monitoring unit and signal processing unit, the modulation and switching unit includes optical switch and parallel first phase modulator, second phase modulator;Signal processing unit is configured to perform cooperative control process: select a phase modulator as main modulator work, based on monitoring unit signal real-time calculation its insertion loss, polarization crosstalk and half-wave voltage;And parameter value is processed with three levels of judgment: when primary judgment parameter value is in first range, start algorithm primary compensation;When based on predicted parameters will enter second range, control optical switch switches to standby modulator work;When parameter exceeds fault threshold, determine fault and alarm switching.The two levels of cooperation of algorithm compensation and device predictive switching effectively inhibit the performance degradation caused by temperature, improve the long-term operation reliability and life of sensor.

The application discloses a kind of optical fiber current sensor harmonic superposition test system, method and measuring system, test system obtains superposed current light signal or single current light signal by optical fiber coil, and is sent to FOCT collector, FOCT collector outputs digital or analog signal, digital signal or analog signal is sent to error operation processing module after conversion channel conversion, the digital signal that current waveform exported by current signal source is sent to error operation processing module after conversion channel conversion after standard device, error operation processing module carries out synchronous error calculation according to the digital signal of first conversion channel transmission and the digital signal (or the digital signal that is output after second conversion channel) of FOCT collector, can display power frequency accuracy, direct current accuracy, harmonic accuracy, single component waveform, superposed current waveform, and is superior to the single harmonic accuracy and waveform that only display of existing harmonic measuring equipment.

The application discloses a kind of all-fiber current sensor noise suppression method, light emitted by light source successively passes through coupler, polarizer, phase modulator, polarization maintaining optical fiber, 1 / 4 wave plate, sensing optical fiber and mirror, and the light reflected by mirror successively passes through sensing optical fiber, 1 / 4 wave plate, polarization maintaining optical fiber, phase modulator, polarizer and coupler, and then enters balanced photodetector positive port M, and the other outlet of coupler is electrically connected with balanced photodetector negative port N through optical attenuator.By adjusting the optical power of input light passing through coupler directly to photodetector through optical attenuator, and replacing common photodetector with balanced photodetector, the purpose of suppressing optical noise and photodetector common-mode noise is achieved, and the signal-to-noise ratio of output signal is improved.

An optical fiber current sensing controller module, where an optical transmitter is energized from a DC source and emits an optical field of calibrated intensity and wavelength to a linear polarizer which generates a reference signal which is then launched in alignment with the transmission axes of a polarization maintaining optical fiber link to a remote and passive fiber optic current sensor (FOCS), where the linearly polarized optical pulse traverses a complete circular path around an energized conductor and is subject to polarization plane rotation in proportion to the magnetic flux density with the integration equal to electric current magnitude according to Ampere's law, and the rotated polarized optical pulse is transmitted back to the optical fiber current sensing controller module via a return fiber optic cable, where the Stokes vector polarization parameters for the returned optical signal are calculated by splitting the elliptically polarized field into four components, passing these components through an analyzer comprised of a linear horizontal polarizer, a linear vertical polarizer, a linear polarizer with transmission axis set at 45 degrees, and a linear polarizer with transmission axis set at 135 degrees, respectively, and where the four separate outputs of the four fiber optic polarizing filters are connected respectively to four separate photodiodes which transduce each optical intensity to analog voltage outputs which are sampled by a digital signal processing chipset, where the Stokes vector parameters for the polarized optical signal are calculated directly from the digitally sampled array of optical intensity values transduced by the photodiodes, and the change in polarization state from which electrical current is measured is derived by comparing the initial linear polarization Stokes vector of the generated reference signal with the measured Stokes parameters of the elliptically polarized optical signal received from the analyzer, and where a sample of the generated polarized reference signal is measured at a photodiode to monitor online sensor network optical attenuation and reference signal power fluctuations.

This disclosure provides embodiments of a current measurement system, method, and apparatus based on an optical fiber current sensor. The system includes: a polarizer converting probe light into linearly polarized light; a phase modulator applying a sine wave to the linearly polarized light to obtain a phase-modulated beam; the phase-modulated beam passing through an optical fiber channel of a polarization-maintaining switch into a corresponding polarization-maintaining transmission fiber, reaching a corresponding sensing fiber ring, forming reflected light, and then returning to the polarizer; a photodetector converting the reflected light into a corresponding electrical signal; an optical switch switching module controlling the polarization-maintaining switch to sequentially select one of N optical fiber channels to be activated; and a current calculation module calculating the modulation depth of the current optical fiber channel in real time based on the electrical signal; and, upon reaching a stable state, calculating the current at the measurement point corresponding to the current optical fiber channel based on the electrical signal. In this way, the current at the measurement point can be accurately and quickly calculated based on the electrical signal, improving the efficiency of cyclic measurement for each channel.

The invention belongs to the technical field of signal processing, and particularly provides a processing method and system for measuring a DC weak signal based on optical fiber current sensing, and the method comprises the steps: employing an optical fiber current sensor to measure a to-be-measured current, and carrying out the balance adjustment of two paths of electric signals S1 and S2 outputted by a dual-path balance detector when the to-be-measured current is zero; demodulating the direct current weak signal; and constructing a calibration fitting model of the measured current-voltage effective signal. According to the invention, direct current weak signal processing can be realized, and balance compensation can be realized.

The application provides an all-fiber current sensor based on linear measurement of sharp wedge interference, linearly polarized light obtained through a polarizer is divided into two mutually orthogonal linearly polarized lights through a coupler, a delay line and a 45-degree fusion splice point, is modulated by an initial phase modulator, is converted into left-handed and right-handed circularly polarized light through a first lambda / 4 wave plate, enters a sensing optical fiber, and a phase difference of the two circularly polarized lights is generated through a Faraday magneto-optic effect; the phase difference is doubled after being reflected by a mirror, is combined into a linearly polarized light through a first lambda / 4 wave plate and a 45-degree fusion splice point, and the phase difference of the circularly polarized light is converted into a rotation of a polarization plane of the linearly polarized light; the rotation of the polarization plane of the linearly polarized light is converted into synchronous translation of a light spot through a coupler, a second lambda / 4 wave plate, a sharp wedge and a polarizer after being twice phase-modulated by a modulator; and linear measurement of a phase delay angle is obtained through positioning of the light spot by an image sensor; the demodulation result of the application is irrelevant to optical power, and is beneficial to separation and compensation of linear birefringence.

The invention discloses an optical fiber current sensor based on multistage cooperative temperature compensation, which comprises an optical sensing unit, a modulation and switching unit, a monitoring unit and a signal processing unit, and is characterized in that the modulation and switching unit comprises an optical switch, and a first phase modulator and a second phase modulator which are connected in parallel; the signal processing unit is configured to execute a cooperative control process: a phase modulator is selected as a main modulator to work, and insertion loss, polarization crosstalk and half-wave voltage of the phase modulator are calculated in real time based on signals of the monitoring unit; carrying out three-stage judgment and processing on the parameter value; starting algorithm primary compensation when the primary judgment parameter value is in a first range; when entering a second range based on the prediction parameter, controlling the optical switch to be switched to a standby modulator to work; and when the parameter exceeds a fault threshold, judging a fault and alarming for switching. Through two-stage cooperation of algorithm compensation and device predictive switching, performance degradation caused by temperature is effectively inhibited, and long-term operation reliability and service life of the sensor are improved.

The invention discloses a passive ultra-large dynamic range optical fiber current sensor comprising a pulse light source used for emitting light pulses; the optical polarizer is used for converting the optical pulse into linearly polarized light; the main coupler is used for dividing the linearly polarized light into a clockwise light path and an anticlockwise light path; the sensing optical fiber ring surrounds a current conductor to be measured and is used for sensing the Faraday effect generated by the current; the light path differentiation module is arranged in the anticlockwise light path and is used for splitting the anticlockwise light into at least two sub-pulses which are separated in time and have different phase offsets; sine and cosine response signals of Faraday phase shift are obtained at the same time through an optical path differentiation module and a signal processing algorithm, and switching and splicing are carried out between linear working areas of the sine and cosine response signals, so that a plurality of piecewise linear responses are seamlessly connected into continuous and ultra-large-range linear output; the problem of phase ambiguity caused by response function periodicity of a traditional open-loop optical fiber current sensor is solved.