33 results about "Fiber optic current sensor" patented technology

The invention discloses a three-phase intelligent disconnecting switch fuse group, which relates to the technical field of circuit protection and comprises an emergency protection circuit device, a three-phase disconnecting switch module, a fuse module, an intelligent control module and a base. According to the invention, the efficiency and reliability of circuit protection can be significantly improved through a three-stage cascade architecture, the optical fiber current sensor and the millimeter wave radar temperature measurement module are integrated by using the multi-physics field coupling detection unit, accurate real-time monitoring of current, temperature and arc characteristics is realized, the sensitivity and accuracy of fault detection are enhanced, and the fault detection efficiency and reliability are improved. The deep learning trigger judgment unit adopts a CNN-LSTM hybrid network, dynamically optimizes a protection threshold and effectively deals with a complex and changeable circuit environment, and the electromagnetic driving emergency processing mechanism adopts a strong magnetic field electromagnet driving technology, so that quick response and efficient execution are ensured, the fault processing time is further shortened, the stability and safety of the system are improved, and the reliability of the system is improved. And the effect of emergency circuit protection is achieved.

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 present invention provides a device for correcting the nonlinear feedback phase shift of a fiber optic current sensor, which is used to perform nonlinear correction on the feedback phase shift output by the output end of the fiber optic current sensor. The device includes a correction coefficient generator, a first multiplier and a second multiplier. The input end of the correction coefficient generator is connected to the output end of the fiber optic current sensor, the output end of the correction coefficient generator is connected to an input end of the first multiplier and the second multiplier is connected to the output end of the fiber optic current sensor, the output end of the first multiplier is connected to an input end of the second multiplier, the second multiplier is connected to the output end of the fiber optic current sensor, and the output end of the second multiplier outputs the corrected feedback phase shift. The present invention also provides a system and method for correcting the nonlinear feedback phase shift of a fiber optic current sensor, which improve the linearity of a flexible fiber optic current sensor within a large dynamic range.

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 invention discloses a fiber current sensor vibration measurement error compensation method and device based on an embedded sensing array, and belongs to the technical field of fiber current sensor vibration measurement. The device comprises a sensing optical fiber, an optical fiber sheath layer, an MEMS sensing array and an optical fiber ring shell, the method comprises the following steps: constructing a prior knowledge base of multi-azimuth degrees of freedom and vibration errors measured when an optical fiber is subjected to external vibration and impact on the basis of a deep learning theory, obtaining error data under different vibration conditions, and training a deep learning model; the vibration error corresponding to the prior knowledge base is sought by measuring the acceleration induced by external vibration and sensed by the MEMS sensors which are arranged in the sensing optical fiber in an embedded array manner, so that the vibration measurement error compensation of the optical fiber current transformer is realized. The method is simple and easy to implement, the measurement method is accurate and efficient, and a feasible scheme is provided for compensation of measurement errors caused when the optical fiber current transformer suffers from external vibration and impact.

The application discloses a current measurement method based on an optical fiber current sensor and belongs to the field of optical fiber sensing. The period of a basic digital square wave is composed of a current signal collection period and a vibration signal collection period, and the size is related to the round-trip time of the modulated light. The current phase shift and the vibration phase shift are collected in the two collection periods respectively, the first digital step wave and the second digital step wave are obtained according to the two phase shifts, the total phase of the optical fiber current sensor is kept at the sensitive point of pi / 2 in the current signal collection period through the reset and closed-loop modulation functions, the total phase of the optical fiber current sensor is kept at the insensitive point of 0 in the vibration signal collection period, the current signal and the vibration signal are obtained, the time of vibration occurrence is determined through the vibration signal, and the vibration filtering is performed on the current signal. The method can improve the measurement precision and stability and avoid the occurrence of false locking accidents.

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 all-fiber type isolated circular polarizer and a preparation method thereof. The all-fiber type isolation circular polarizer comprises three parts, namely a fiber type polarizer, a fiber type lambda / 4 wave plate and a holding fiber, the fiber type polarizer and the fiber type lambda / 4 wave plate with a certain length are connected in a manner that an axial included angle is 45 degrees, the lambda / 4 wave plate is prepared from novel high-birefringence crystal derived fibers, and the holding fiber is made of high-birefringence crystal derived fibers. The optical fiber type polarizer is composed of a single-polarization optical fiber, a D-type optical fiber, a 45-degree inclined grating or any optical fiber type device with a polarization effect. The all-fiber device which is manufactured based on an improved welding mode and integrates circular polarization and isolation characteristics has the advantages of high temperature resistance, ultra wide band, high performance, low cost, compactness, easiness in integration and the like; the method can be applied to the fields of optical fiber gyroscopes, AR / VR equipment, optical fiber current sensors, high-power laser, optical fiber communication, medical imaging, quantum communication, material structure analysis and measurement and the like.

The invention discloses a while-drilling focused resistivity foresight logging method and device based on optical fiber current sensing, and relates to the field of geological advanced detection, and the method comprises the steps: a constant current source generates a current; the exploring electrode applies current to the drill collar close to a drill bit to form shielding current and exploring current; the return electrode receives current to form a current loop; measuring the voltage close to the drill collar in real time; measuring a detection current by using an optical fiber current sensor; calculating apparent resistance and apparent resistivity of the front geologic body; and current is adjusted to ensure constant power. The device comprises a detection electrode, a return electrode, an amplitude-adjustable constant current source, an optical fiber current sensor, a voltage measurement module, a self-adaptive constant power control module and a measurement signal acquisition module. The beneficial effects are that the low-frequency focusing current can overcome the defect that a high-frequency electromagnetic wave signal rapidly attenuates in a medium-high resistance stratum, the optical fiber current sensing technology improves the detection precision of the detection current, and the constant power mode improves the stratum adaptability and the measurement dynamic range.

The present application relates to the technical fields of optical fiber current sensor monitoring, and discloses a state monitoring device for optical fiber current sensor, which comprises a device body, the device body comprises an optical fiber monitoring box, an optical fiber monitoring device and an optical fiber monitoring top cover; wherein, a partition is arranged in the optical fiber monitoring box, the partition separates the inside of the optical fiber monitoring box into multiple independent cavities, and a wire passing port is arranged on the side wall of the optical fiber monitoring box and communicates with the independent cavities; the optical fiber monitoring device is multiple and arranged in each independent cavity; the optical fiber monitoring top cover is connected with the optical fiber monitoring box to form a closed box structure, the inner surface of the optical fiber monitoring top cover is provided with an embedded connector corresponding to the optical fiber monitoring device, and the outer surface of the optical fiber monitoring top cover is provided with an ammeter, and the embedded connector is used for connecting the optical fiber monitoring device and the ammeter. The present application also discloses a state monitoring method for optical fiber current sensor.

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 discloses a method for manufacturing an ultra-high-sensitivity optical fiber current sensor. The method specifically comprises the following steps of: 1, manufacturing a cascaded Fabry-Perot interferometer structure, namely FPI (Fabry-Perot Interferometer); 2, dimethyl silicone oil with the refractive index n equal to 1.40 is injected into the large capillary tube and the small capillary tube of the cascade structure; 3, uniformly coating the conductive silver adhesive mixture on the surfaces of the large capillary tube C1 and the small capillary tube C2 to form a sensor sensitive to current; fourthly, in order to prevent Joule heat generated by the conductive silver adhesive from being diffused or convected by the environment, a transparent hard plastic shell is arranged on the outer surface of the structure in a sleeving mode, the heat generated by the conductive silver adhesive can be rapidly absorbed by the temperature sensor, and high-sensitivity measurement of the current is indirectly achieved; the current sensor manufactured by the method is particularly compact in structure, simple to manufacture, easy to package and high in sensitivity.

The invention discloses a device and a method for detecting alternating voltage based on an optical fiber current sensor, and solves the technical problem of low voltage detection accuracy in the prior art. The device comprises a solenoid which is a wire wound spirally, and the wire is provided with a first end and a second end; the plurality of capacitors are arranged, the capacitance values of the plurality of capacitors are different, and any capacitor is operably connected with the first end of the wire in series; a sensing head of the optical fiber current sensor is located in the solenoid; the second end of the wire and the capacitor are respectively used for connecting two joints with different electromotive forces. According to the device and the method provided by the invention, the sensitivity and the accuracy of alternating-current voltage detection are improved.

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 provides an all-fiber current sensor based on S wave plate linear measurement, which is based on Sagnac effect, Faraday magneto-optic effect and S wave plate; linearly polarized light is obtained through a polarizer, and the linearly polarized light is divided into two mutually orthogonal linearly polarized lights through a delay line and a 45-degree fusion splicing point; the linearly polarized light is modulated by a modulator, and then enters a λ / 4 wave plate and is converted into left-handed and right-handed circularly polarized light; after entering a sensing optical fiber, the measured circuit current magneto-optic effect makes the two circularly polarized lights produce a phase difference; the phase difference is doubled through a fiber end mirror and a sensing optical fiber, and the linearly polarized light is combined into linearly polarized light through a λ / 4 wave plate, a modulator and a 45-degree fusion splicing point; the phase difference of the circularly polarized light is converted into the rotation of the linearly polarized light polarization plane; the linearly polarized light after the secondary modulation passes through an S wave plate and a polarizer in turn, and the rotation of the polarization plane is converted into the synchronous translation of the light spot; the phase difference and the current value are obtained by positioning the light spot through an image sensor; the application has the advantages of optical power independence and linear birefringence complete compensation.

The invention discloses a vibration test method and system for a polarization-maintaining optical cable of an optical fiber current transformer, and the method comprises the steps: laying the polarization-maintaining optical cable in an optical cable groove box, and enabling the polarization-maintaining optical cable to be connected with an optical fiber current sensor and an acquisition unit; injecting current into the optical fiber current sensor, and transmitting an output signal of the optical fiber current sensor to the acquisition unit through the polarization-maintaining optical cable; based on the heavy object falling test scheme, carrying out a heavy object falling test on the polarization-maintaining optical cable to obtain a heavy object falling output signal; based on the vibration table impact vibration test scheme, performing a vibration table impact vibration test on the polarization maintaining optical cable to obtain a vibration table impact vibration output signal; based on the vibration table sweep frequency vibration test scheme, performing a vibration table sweep frequency vibration test on the polarization maintaining optical cable to obtain a vibration table sweep frequency vibration output signal; and respectively determining anti-vibration effects of the test schemes, and guiding anti-vibration measures of the polarization maintaining optical cable based on the anti-vibration effects.

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 provides a linear measurement all-fiber current sensor, linearly polarized light is obtained through a polarizer, and is divided into two mutually orthogonal linearly polarized lights, and is further converted into left-handed and right-handed circularly polarized light to input a sensing optical fiber, a Faraday magneto-optic effect of current is used to make the two circularly polarized lights have a phase difference, the circularly polarized light is reflected by a mirror at the end of the sensing optical fiber, and then the phase difference is doubled through the sensing optical fiber, and the circularly polarized light is combined into a linearly polarized light through a λ / 4 wave plate, a modulator secondary phase modulation and a 45° fusion splice point, meanwhile, the phase difference of the circularly polarized light is converted into the rotation of the linearly polarized light polarization plane, and the rotation of the linearly polarized light polarization plane is converted into the synchronous translation of a light spot through a coupler, a beam expander and a radial polarization grating, and the phase difference is obtained by positioning the light spot through an image sensor; the application realizes linear demodulation of a Faraday magneto-optic rotation angle, has the advantages of being irrelevant to the measurement result and optical power, being beneficial to the separation compensation of linear birefringence, realizing non-distortion harmonic measurement and the like.

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.