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405 results about "Frequency stabilization" patented technology

Frequency stabilization. Process of controlling the center or carrier frequency so that it differs from that of a reference source by not more than a prescribed amount.

SF6 gas leakage detection method and system based on photoacoustic spectrum analyzer

The invention discloses an SF6 gas leakage detection method and system based on a photoacoustic spectrum analyzer, and the method comprises the steps: arranging a sampling end to collect an SF6 gas sample, and obtaining stable gas input through constant-current sampling and steady-state pretreatment; steady-state gas is guided into the photoacoustic spectrum analyzer, and resonance frequency stabilization and signal amplification output are achieved through the self-tuning unit; executing double-microphone differential detection and digital filtering processing, and outputting a stable SF6 detection signal with a high signal-to-noise ratio; performing time calibration, abnormity elimination and consistency processing on the detection signal to generate standardized detection data; inputting the standardized data to a Transform model, and performing inversion to generate an SF6 leakage source position and a diffusion path; and displaying an inversion result on a monitoring interface, triggering a sound-light alarm when the inversion result exceeds a limit, and uploading the inversion result to a cloud monitoring platform. According to the invention, the intelligent photoacoustic spectrum system combining photoacoustic-fluid steady-state control and self-tuning detection is constructed, so that high-sensitivity detection and accurate positioning of SF6 gas leakage are realized.
Owner:BEIJING DUKETECH TECH CO LTD

Optical storage parallel network control method

The invention provides an optical storage parallel network control method, which comprises the following steps: calculating the current load rate percentage of each residual unit according to the connection relation and electrical path information of the residual units after isolation; evaluating the available margin capacity and the frequency regulation bearing capacity of the remaining units, matching the available margin capacity and the frequency regulation bearing capacity with a specific power value and a frequency regulation requirement which need to be compensated, and determining a feasible unit combination scheme for fault recovery; generating a power redistribution list and a frequency adjustment responsibility distribution table according to the direct current bus connection mode of the optimal unit recombination, and obtaining an output power set value and a frequency adjustment parameter of each unit after adjustment; and extracting the continuous power supply time value of the optical storage parallel network, updating the total power supply capacity value of the optical storage parallel network, and maintaining the continuous power output and frequency stability after the fault of the optical storage parallel network.
Owner:FOSHAN NEW CAPITAL CONSTR TECH CO LTD

Phase-locking frequency-stabilizing multi-core control radio frequency system

The invention relates to the technical field of radio frequency generator circuits, and provides a phase-locking frequency-stabilizing multi-core control radio frequency system, which processes I / Q signals and constructs a multi-core task allocation and cooperation mechanism through a digital baseband processing module, and performs pre-distortion processing and system scheduling. The double-closed-loop control module is used for stabilizing fundamental frequency, correcting temperature drift and compensating and adjusting frequency swing amplitude; the hybrid power amplification module is used for performing multi-stage hybrid power amplification signal processing and temperature monitoring through a driving stage and output stage combined topology; and the feedback sampling network module collects output signals in real time through a directional coupler and feeds back, adjusts and precisely controls the frequency stability according to the output signals.
Owner:JIANGSU PULI YOUCHUANG TECH CO LTD

Laser frequency stabilization system based on Faraday anomalous dispersion atomic filtering

The invention discloses a laser frequency stabilization system based on Faraday anomalous dispersion atomic filtering, which is used for carrying out frequency stabilization on phase modulation multi-sideband laser, and comprises a frequency doubling laser unit which is configured to comprise a fundamental frequency seed light source, an electro-optical modulator, a fundamental frequency amplifier and a frequency doubling crystal; the light splitting module unit is configured to split the frequency doubling light into a main output light path and a monitoring light path; the atomic optical rotation filter is located on the monitoring light path and is configured to maintain the purity of the frequency-stabilized laser spectrum through purification treatment under the control of the axial magnetic field and the temperature; the frequency stabilization unit is configured to be a frequency stabilization light path and a servo system, and the frequency stabilization light path is used for obtaining laser frequency information and generating an error signal; the servo system is used for controlling the frequency of the fundamental frequency seed light source according to the error signal feedback. According to the laser frequency stabilization system provided by the invention, the spectrum purification and frequency stabilization precision can be improved, so that high-frequency stability locking is realized.
Owner:NATIONAL INSTITUTE OF METROLOGY CHINA

Frequency stability control method for accessing new energy to offshore energy platform

The invention discloses a frequency stability control method for accessing new energy to an offshore energy platform, and the method comprises the steps: firstly carrying out the state recognition and parameter extraction of frequency modulation resources, building a frequency-power response model of the frequency modulation resources, carrying out the superposition construction of a system frequency response total model, and carrying out the packaging of a dictionary structure; based on a frequency safety index, disturbance occurrence and grade are judged in real time, and a frequency change trend is dynamically estimated; according to the disturbance level and the response characteristics of various resources, a fast-medium-slow layered frequency modulation control strategy is constructed, different types of resources are scheduled in stages for cooperative adjustment, the frequency state is monitored, and control parameters are dynamically corrected; constructing a fuzzy logic controller to process nonlinear disturbance, and introducing a whale optimization algorithm to set and optimize parameters of the fuzzy controller; and finally, dynamically correcting the control strategy according to the frequency control result and the resource utilization rate index. The method can guarantee the frequency stability, reduces the frequency modulation cost, and improves the frequency control precision, the response speed and the overall operation toughness.
Owner:SOUTHEAST UNIV +1

VCO digital circuit control method and system with temperature compensation

The invention provides a VCO digital circuit control method and system with temperature compensation, and relates to the technical field of circuit control, and the method comprises the steps: obtaining VCO output frequency and real-time temperature, and calculating an initial frequency deviation; correcting the frequency deviation based on the temperature compensation coefficient, and generating a temperature-frequency deviation characteristic curve; an optimal compensation factor is determined through Monte Carlo sampling; calculating a compensation parameter adaptive weight by using Bayesian iteration, and dynamically adjusting a compensation factor; and a control signal is generated through the digital integrator to realize frequency calibration. According to the invention, the high-precision frequency stability of the VCO under the temperature change condition is realized, and the circuit reliability is improved.
Owner:ZHEJIANG FANSHUANG TECH CO LTD

Intelligent diagnosis system for electricity consumption abnormity information acquisition

The invention discloses an intelligent diagnosis system for power utilization abnormal information acquisition, particularly relates to the technical field of power system monitoring, and is used for solving the problems of waveform distortion and broadening caused by transmission line distribution parameters in the long-distance wired transmission process of an existing system. The system collects abnormal characteristic waveform data through a distributed intelligent terminal, selects a characteristic harmonic component in the power frequency voltage of a power line to construct an inherent test signal, extracts the envelope form similarity of a response signal and the test signal through envelope analysis as a first distortion evaluation index, and obtains a second distortion evaluation index after statistical significance judgment. Performing instantaneous frequency stability analysis on the signal with significant distortion to obtain a second distortion evaluation index, and finally generating a corresponding waveform compensation parameter based on double indexes to realize real-time compensation correction; the integrity of the abnormal characteristic waveform in the transmission process is effectively maintained, and the accuracy and reliability of power consumption abnormity diagnosis are remarkably improved.
Owner:GUANGXI POWER CO LTD HECHI POWER SUPPLY BUREAU

Device for improving atom coherent population trapping efficiency and implementation method

The invention relates to the technical field of quantum measurement, in particular to a device for improving atom coherent population trapping efficiency and an implementation method. Screening candidate frequency points; judging a temporary frequency point; extracting concerned frequency points; correcting a target frequency point; c field and power adjustment; and applying a radio frequency field and performing frequency locking output. According to the invention, the radio frequency sweep frequency operation is carried out at the preset C field current value and the preset radio frequency power in the high-altitude field area, and the real-time collection and analysis of the transmitted light intensity, the internal temperature of the cavity and the external air pressure are combined, so that the target frequency point is screened from the original to-be-determined frequency points in a multi-level and multi-angle manner; and the C-field current and the radio frequency power are dynamically adjusted, so that high-precision locking of the radio frequency output frequency is further realized, the imprisoning efficiency of atom coherent population can be remarkably improved, the adaptive capacity and the compensation capacity of the system to external disturbance are enhanced, and the system has relatively high environmental robustness and frequency stability.
Owner:BEIJING ACAD OF QUANTUM INFORMATION SCI

Narrow-linewidth single-frequency laser frequency stabilization system and method based on Gaussian filter

The invention provides a narrow-linewidth single-frequency laser frequency stabilization system and method based on a Gaussian filter, and the system employs the Gaussian filter to reduce the optical power of single-frequency laser, and employs the frequency selection characteristic of the Gaussian filter, the frequency spectrum of the single-frequency laser is a single narrow peak, and the frequency stability of the single-frequency laser is improved. When laser frequency passes through a designed Gaussian filter (the fluctuation range of a frequency-stabilized laser source is only on the left side of the center frequency of the Gaussian filter), laser signals can be reduced according to a Gaussian function rule, and along with frequency change, attenuation degrees are different and monotonically change, so that output optical power is different, and the output optical power is changed. And the optical power is compared with the optical power of a preset frequency stabilization target (a half-high point on the left side of a Gaussian filter) to obtain the deviation of the laser source relative to the target frequency stabilization frequency, so that the laser frequency is correspondingly adjusted to achieve the frequency stabilization purpose. The high-sensitivity optical power detection is realized, the response speed and the frequency stabilization precision of the system are improved, and the system is simple in structure and low in maintenance cost.
Owner:HUNAN HAOMIN PHOTOELECTRIC TECH CO LTD

New energy power system frequency supporting capability quantitative evaluation method and system based on frequency band analysis

The invention discloses a new energy power system frequency supporting capability quantitative evaluation method and system based on frequency band analysis. Aiming at the frequency response difference of multiple types of power generation equipment in a new energy power system, a unified system frequency response model is established in a frequency domain, and the frequency supporting capability of the power generation equipment under different frequency bands is quantified by adopting a frequency band analysis method. Comprising the following steps: establishing a frequency response transfer function matrix based on a linearized dynamic equation of a multi-machine system; calculating a frequency band H2 / H infinity norm index in a selected frequency range to quantitatively characterize the stability performance of the system in inertia response and a primary frequency modulation stage; through normalization processing of the reference capacity and frequency of the system, comparison of frequency supporting capabilities of different devices and systems is realized. The response difference and contribution of the synchronous machine and the wind and light storage power electronic interface power supply in each frequency band can be accurately revealed, and a unified and effective frequency domain analysis method is provided for frequency modulation control design and frequency stability evaluation of a new energy power system.
Owner:ZHEJIANG UNIV

System reference clock frequency accuracy automatic calibration circuit and calibration method thereof

The invention discloses a system reference clock frequency accuracy automatic calibration circuit and a calibration method thereof, and belongs to the technical field of frequency sources, the calibration circuit comprises a first crystal oscillator, a first power divider, a second power divider, a second crystal oscillator, an analog switch, a radio frequency switch, a detector, a comparator, an FPGA controller, a digital analog converter, an operational amplifier and a temperature sensor. When an external high-precision reference clock is accessed, the FPGA controller automatically switches a frequency measurement reference, performs high-precision frequency measurement on a 100MHz signal output by the first crystal oscillator, and judges whether calibration is needed or not according to frequency offset; if calibration is needed, the output voltage of the digital-to-analog converter is adjusted, the Vc end of the first crystal oscillator is controlled after operational amplification, and frequency closed-loop adjustment is achieved. According to the method, the crystal oscillator does not need to be disassembled, calibration is rapidly completed on site, and system availability and long-term frequency stability are remarkably improved.
Owner:CHENGDU SHIYUAN FREQUENCY CONTROL TECH

Crystal oscillator taming system based on Kalman filtering and adaptive PID

The invention discloses a crystal oscillator taming system based on Kalman filtering and adaptive PID, and relates to the technical field of time-frequency equipment. Comprising a crystal oscillator time frequency module used for generating a local time frequency signal, a reference module used for receiving an external reference time frequency signal, an error measurement module used for measuring the phase deviation between the local time frequency signal and the reference time frequency signal, and a Kalman filtering estimation module used for performing Kalman filtering estimation based on the phase deviation. The Kalman filtering module is used for outputting phase deviation estimation and covariance estimation and adaptively adjusting PID parameters according to the phase deviation estimation, the position deviation estimation and the covariance estimation; the control feedback module is used for superposing the voltage-controlled voltage adjustment quantity to the crystal oscillator time frequency module to adjust the output frequency of the crystal oscillator; according to the method, the crystal oscillator taming parameters are dynamically adjusted through Kalman filtering in combination with self-adaptive PID, high-precision and robust taming of the crystal oscillator is achieved, and the long-term frequency stability and the time synchronization precision of the crystal oscillator are improved.
Owner:CHENGDU JINNUOXIN HIGH-TECH CO LTD

Virtual inertia adaptive control method, device and system

The invention provides a virtual inertia adaptive control method, device and system, and relates to the technical field of inverter system control. The method comprises the following steps: calculating a reference current value according to a power reference value and an actual output voltage; calculating a current deviation value according to the reference current value and the actual output current value; outputting the current deviation value to an adaptive resonance controller to obtain a compensation control voltage signal; inputting the compensation control signal to an AHO virtual oscillator to obtain a reference value of the output voltage of the inverter; and controlling the output of the three-phase inverter circuit according to the reference value of the inverter output voltage. Wherein the adaptive resonance controller carries out adaptive control through the proportional parameter and the proportional resonance inertial parameter. The virtual inertia output can be dynamically adjusted according to the real-time requirement of the system, the overshoot phenomenon caused by power oscillation is effectively suppressed while the frequency stability is met, and the capacity of the system for resisting sudden load change and frequency disturbance is enhanced.
Owner:YANSHAN UNIV

Thin-film suspended microacoustic resonators for timing applications

A piezoelectric Micro-Electro-Mechanical Systems (MEMS) resonator employs a thin-film piezoelectric layer as an anchor, which eliminates a dominant loss source, anchor loss, which stems from the irreversible mechanical energy radiation through the anchors. By implementing fundamental or higher-order thickness Lame modes (TLMs) in the thickness direction, the piezoelectric resonator exhibits a substantial reduction of thermoelastic damping (TED) and increase of anchor quality factor. The piezoelectric resonator also provides temperature stability by utilizing a substrate with a turnover temperature, minimizing deviation on resonance frequency. This approach enables the use of thin-film piezoelectric materials as anchors, which can be precisely controlled to minimize losses. The piezoelectric resonator's compact design and CMOS-compatibility make it suitable for batch production at a minimal cost per unit. Furthermore, the highly frequency-stable temperature point of the piezoelectric resonator can be used for implementing oven-controlled oscillators for ultra-stable clock generation in various applications.
Owner:UNIVERSITY OF CENTRAL FLORIDA RESEARCH FOUNDATION INC

Multi-type resource participation power grid frequency modulation method based on consistency algorithm

The invention discloses a multi-type resource participation power grid frequency modulation method based on a consistency algorithm, and the method comprises the steps: firstly constructing an improved frequency response model fusing distributed optical storage equipment, hydrogen storage and energy storage equipment and a DC flexible load, identifying system parameters, solving a multi-resource comprehensive adjustment coefficient, constructing a directed graph model, employing a grouping consistency algorithm, and obtaining a multi-type resource participation power grid frequency modulation model; the optimal adjustment coefficient of each resource is solved through distributed optimization of an augmented Lagrange function and a consistency index, and primary frequency modulation of a multi-type resource collaborative response system is driven. According to the multi-type resource participation power grid frequency modulation method based on the consistency algorithm, by driving a multi-type resource collaborative response system to perform primary frequency modulation, collaborative regulation and control of light storage, hydrogen storage and flexible load are realized, economy and operation constraints are considered through distributed optimization, and communication complexity is reduced through a clustering iteration mechanism; and the frequency stability of the high-proportion new energy power grid is obviously improved.
Owner:STATE GRID HUBEI ELECTRIC POWER CO XIAOGAN POWER SUPPLY CO

A method, device and medium for constructing a light storage and charging alternating current-direct current hybrid microgrid

The present application relates to a kind of light storage fills in and mixes direct current hybrid microgrid network control method, equipment and medium, the method is according to the SOC value of energy storage device and is classified management to energy storage converter.Priority high converter switches to VSG mode, detect whether microgrid voltage and frequency fluctuation exceeds adjustment dead zone.When frequency fluctuation exceeds, active power output is adjusted by VSG mode;When voltage fluctuation exceeds, adjust reactive power output. Energy storage device is switched to VSG mode gradually, when demand cannot be met, photovoltaic equipment and electric vehicle are sequentially put into support grid.Before photovoltaic equipment access, its voltage is consistent with the connected energy storage device, and is converted into VSG mode.If still need further support, then by adjusting charging pile control algorithm, electric vehicle is fed back.Electric vehicle also needs to synchronize voltage and phase before access, to support microgrid.This method significantly improves the voltage and frequency stability of microgrid system.
Owner:CRRC ZHUZHOU ELECTRIC LOCOMOTIVE RESEARCH INSTITUTE CO LTD

Passive laser gyroscope based on light force induced transparency effect and measuring method thereof

The invention provides a passive laser gyroscope based on a light force induced transparency effect and a measurement method thereof, the passive laser gyroscope comprises a frequency stabilized laser light source, a signal modulation input device, a balance homodyne detection device, an annular optical resonant cavity and a signal detection and feedback device, wherein a reflection cavity mirror with a photomechanical resonance structure characteristic is integrated in the annular optical resonant cavity; according to the passive laser gyroscope, a narrow transparent window modulated by a mechanical damping rate is generated on an annular optical resonant cavity of the passive laser gyroscope by utilizing a light force induced transparency effect and a light-mechanical coupling effect, so that the quality factor of the annular optical resonant cavity is improved, and the measurement sensitivity of the passive laser gyroscope is enhanced.
Owner:SUN YAT SEN UNIV

Power system operation strategy generation method and device, equipment, medium and product

The invention discloses a power system operation strategy generation method and device, equipment, a medium and a product, and belongs to the technical field of power system automation control. The method comprises the following steps: establishing a cooperative operation model of a wind turbine generator and a battery energy storage system participating in power grid primary frequency modulation; deriving an analytic expression of frequency stability constraints of the power system based on the collaborative operation model, wherein the frequency stability constraints comprise a maximum frequency change rate constraint, an overshoot constraint and a static frequency deviation constraint; constructing a wind power uncertainty model based on the uncertainty budget; constructing a mixed integer linear programming scheduling model taking the minimum total operation cost as a target; and solving the mixed integer linear programming scheduling model to obtain a power system operation strategy. According to the embodiment of the invention, the frequency safety level of the power system can be remarkably improved under the wind power uncertainty.
Owner:CHINA SOUTHERN POWER GRID COMPANY +1

Beat frequency comparison device mediated by optical frequency comb

The invention discloses a beat frequency comparison device mediated by an optical frequency comb. The beat frequency comparison device comprises the optical frequency comb, a first frequency stabilized laser, a first beat frequency device, a first frequency mixer, a first high-pass filter, a second frequency stabilized laser, a second beat frequency device, a second frequency mixer, a second high-pass filter, a DDS signal generator, a third frequency mixer and a low-pass filter. Frequency-stabilized lasers output by the first frequency-stabilized laser and the second frequency-stabilized laser and an optical frequency comb output by the optical frequency comb are subjected to beat frequency in the first beat frequency device and the second beat frequency device respectively, and first beat frequency and second beat frequency are obtained; the first beat frequency and the second beat frequency are mixed with the carrier envelope offset frequency of the optical frequency comb, and a first sum frequency and a second sum frequency are filtered out; the first sum frequency obtains a synthetic frequency through direct digital frequency synthesis; the second sum frequency and the synthetic frequency are mixed in the third mixer, and then the difference frequency is filtered out through the low-pass filter. According to the invention, beat frequency comparison of frequency-stabilized lasers with different wavelengths can be realized, and the influence of the stability of the optical frequency comb is avoided.
Owner:BEIJING CHANGCHENG INST OF METROLOGY & MEASUREMENT AVIATION IND CORP OF CHINA

Low-cost precise time keeping method, system and device based on gating circulation unit

The invention discloses a low-cost precise time keeping method, system and device based on a gating circulation unit, and relates to the technical field of power grid measurement. The method is executed when the synchronous phasor measurement device cannot receive external signals, and comprises the following steps: monitoring operation parameters which influence the frequency stability of an internal crystal oscillator of the phasor measurement unit in real time; calculating a current frequency error of the crystal oscillator in real time by using a crystal oscillator frequency drift prediction model based on a gated cycle unit network based on the operation parameters; generating a time correction amount according to the current frequency error; and applying the time correction to a local clock of the phasor measurement unit to compensate the frequency drift of the crystal oscillator so as to realize accurate time keeping. According to the invention, through accurate prediction of crystal oscillator errors and lightweight software compensation, the synchronous phasor measurement device adopting a low-cost crystal oscillator can also realize long-time high-precision time keeping, the hardware cost is obviously reduced, and the reliability of power grid monitoring during the Beidou / GPS lock losing period is improved.
Owner:SUQIAN POWER SUPPLY COMPANY OF JIANGSU PROVINCE POWER +1

Power system inertia online evaluation method, device, equipment and medium

The invention relates to the technical field of power system frequency stability control, in particular to a power system inertia online evaluation method and device, equipment and a medium, and the method comprises the steps: obtaining frequency deviation data and active power data of each node, carrying out the low-pass filtering of the frequency data, and calculating the amount of active unbalance; an inertia response model is constructed based on the rotor motion equation of the synchronous generator, and inertia and damping coefficients are estimated by using a least square method; constructing a transfer function and judging the stability of the transfer function, if the transfer function is stable, inputting an active unbalance amount to obtain a frequency deviation predicted value, and calculating a Pearson correlation coefficient with an actual frequency; different time periods are selected through a sliding window to repeat the process, finally, the inertia corresponding to the maximum Pearson's correlation coefficient is selected as a system inertia evaluation result, the inertia level of the system can be accurately evaluated on line through the method, and therefore data support is provided for frequency control, and the frequency stability and safety of the system are guaranteed.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD RESEARCH INSTITUTE +1

Thermal power-gas turbine-energy storage regional power grid frequency modulation power distribution method

The invention discloses a thermal power-gas turbine-energy storage regional power grid frequency modulation power distribution method, and relates to the technical field of power system frequency stability control, and the method comprises the following steps: S1, carrying out the dynamic modeling of a multi-energy frequency modulation system; s2, designing a hierarchical control architecture; s3, designing an adaptive power distribution algorithm; s4, constructing a constraint optimization model; and S5, designing a closed-loop control flow. The technical problem to be solved by the invention is to provide a thermal power-gas turbine-energy storage regional power grid frequency modulation power distribution method, and provides a whole-process method of modeling, hierarchical control, adaptive distribution, constrained optimization and closed-loop execution. The control targets that the frequency is quickly recovered (less than or equal to 2s), the power distribution error is less than or equal to 5%, and the energy storage SOC is maintained within the safety interval of 20%-80% are achieved, and the frequency stability and the operation economy of a regional power grid are improved.
Owner:XIAN THERMAL POWER RES INST CO LTD +1

Cooperative frequency modulation method and system for hybrid flywheel energy storage system

The invention relates to the technical field of power system frequency modulation control, and discloses a collaborative frequency modulation method and system of a hybrid flywheel energy storage system. The method comprises the following steps: constructing a hybrid energy storage array consisting of a power type flywheel array and an energy type flywheel array which are respectively responsible for millisecond-level frequency support and second-level frequency recovery; a double-layer cooperative control structure is designed, the upper layer carries out total power distribution and coordination based on power grid frequency deviation and change rate, and the lower layer carries out instruction execution through speed and current double-closed-loop control; a state manifold design based on a Lyapunov stability theory is introduced; and a self-adaptive gain adjustment mechanism is adopted, flywheel output is dynamically adjusted according to the real-time characteristic of frequency disturbance, and dynamic cooperative scheduling of the two types of flywheels under different time scale frequency fluctuations is achieved. According to the method, the adaptive capacity, the response speed and the control precision of the hybrid flywheel system to complex frequency disturbance are effectively improved, and the frequency stability of a power grid is enhanced.
Owner:INNER MONGOLIA UNIV OF TECH +1

Resonant bionic cilium vector hydrophone based on quartz tuning fork and underwater acoustic system

The invention provides a resonant bionic cilia vector hydrophone based on a quartz tuning fork and an underwater acoustic system, and relates to the technical field of micro-mechanical electronics. A vibration detection mechanism in the hydrophone comprises two quartz tuning forks located in a first axial direction and two quartz tuning forks located in a second axial direction, the first axial direction is perpendicular to the second axial direction, one end of each quartz tuning fork is fixed, and the other end of each quartz tuning fork is connected with a vibration acquisition mechanism; and the vibration acquisition mechanism is connected with the quartz tuning forks and is used for driving the two quartz tuning forks in the same axial direction to generate symmetrical frequency deviation under the action of sound waves. According to the embodiment of the invention, the excellent frequency stability and strain sensitivity of the double-end fixed tuning fork can be utilized to realize efficient conversion of sound signals and generation of corresponding electric signals, digital signal output can be conveniently realized, high-sensitivity detection of the sound signals can be effectively realized, the influence of common-mode signals can be inhibited, the anti-interference performance is good, and the detection precision is high. And the underwater sound detection effect is greatly improved.
Owner:YUNJI XINGGUANG (ZHUHAI) MICROELECTRONICS CO LTD +1

Laser frequency stabilization device and method based on optical frequency shift

The invention provides a laser frequency stabilization device and method based on optical frequency shift, and relates to the field of laser frequency stabilization, and the device comprises a first slave laser, a first frequency stabilization system, a second slave laser, a second frequency stabilization system, a master laser, an acousto-optic modulation module, and a phase-locked frequency stabilization device. The first slave laser is used for emitting first laser of a first wavelength; the main laser is used for emitting third laser with a second wavelength; the first frequency stabilization system is used for locking the first laser according to the first laser to obtain first frequency-stabilized laser; the second slave laser is used for emitting second laser with the first wavelength; the second frequency stabilization system is used for locking the second laser to obtain second frequency-stabilized laser; the acousto-optic modulation module is arranged between the first slave laser and a light path of the phase-locked frequency stabilization equipment; and the phase-locking frequency stabilization equipment is used for receiving the first frequency stabilized laser and the second frequency stabilized laser and carrying out frequency locking on the third laser according to the first frequency stabilized laser and the second frequency stabilized laser. According to the invention, the modulation transfer spectrum and the optical frequency shift can be combined to complete frequency locking of the laser.
Owner:PEKING UNIV

Gas saturation absorption optical path structure based on dual optical path enhancement

The invention provides a gas saturation absorption optical path structure based on dual optical path enhancement, which belongs to the field of laser optical path design and comprises an optical fiber circulator, a gas absorption chamber and an optical fiber reflector. A first port of the optical fiber circulator is connected with a laser output optical fiber, a second port of the optical fiber circulator is connected with an input collimator of the gas absorption chamber, and a third port of the optical fiber circulator is connected with a detector and is used for providing frequency reference for gas absorption; and the optical fiber reflector is connected with the output end of the gas absorption chamber. According to the invention, the physical contradiction between the air chamber size and the optical path gain is broken through, and a compact frequency stabilization system with miniaturization and high stability is realized.
Owner:THE 41ST INST OF CHINA ELECTRONICS TECH GRP

New energy power station grid connection method and system based on satellite time service and synchronous compensation

The invention discloses a new energy power station grid connection method and system based on Beidou satellite time service and synchronous compensation, and the method comprises the steps: receiving a Beidou satellite time service signal, generating unified reference synchronization time, and calculating a reference synchronization phase angle according to the reference synchronization time; taking the reference synchronous phase angle as a control reference, and driving a grid-forming inverter to execute grid-connected operation; the integrity index of the Beidou time service signal is monitored in real time, and when it is detected that the Beidou time service signal is abnormal or invalid, at least one stage of synchronous compensation mechanism is started according to the abnormal or invalid duration time and the system operation state so as to maintain the phase continuity and frequency stability of the grid-connected operation of the new energy power station.
Owner:CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY

Main sound source noise identification method and system for flexible direct current converter station

The invention relates to the technical field of noise identification, in particular to a main sound source noise identification method and system for a flexible direct current converter station. Obtaining the current of the converter station and the audio time sequence data of each monitoring point; processing the audio time sequence data to obtain a time-frequency diagram, analyzing the amplitude change difference of different monitoring point positions under the same time-frequency point, adjusting the amplitude change condition of the time-frequency point of a target point position according to the amplitude change difference, obtaining an amplitude change index, and conveniently analyzing whether noise is from a converter transformer or not; for the magnetostrictive noise of the converter transformer core, the vibration frequency is stable, and the amplitude is synchronously changed along with the current, so that the correlation between the amplitude change index and the current time sequence data and the difference of the time sequence characteristics under each frequency are analyzed in the target point location time-frequency diagram, and the multi-frequency synchronization index is determined; the possibility that a frequency component is derived from an iron core magnetostriction effect is reflected; and finally, the amplitude change and the multi-frequency synchronization index are fused, the noise characteristics are integrated, and the noise source identification accuracy is improved.
Owner:STATE GRID JIANGXI ELECTRIC POWER CO LTD

Frequency support control method and device for flexible direct current power transmission system

The invention provides a frequency support control method and device of a flexible DC power transmission system. Inertia control is carried out on the actual frequency of the flexible direct current partition alternating current power grid, a direct current voltage dynamic correction value of a converter station in the flexible direct current power transmission system is obtained, a d-axis alternating current component and a q-axis alternating current component of the converter station are calculated, and then frequency support control is carried out on the flexible direct current power transmission system. The dynamic frequency response characteristic of the flexible direct-current power transmission system is remarkably improved through inertia control, and the frequency stability of the flexible direct-current partition alternating-current power grid is guaranteed. According to the method, inertia control is carried out on the actual frequency of the flexible direct-current partitioned alternating-current power grid, the frequency change rate of the flexible direct-current partitioned alternating-current power grid is rapidly suppressed at the initial stage of the fault, the frequency drop amplitude of the flexible direct-current partitioned alternating-current power grid is reduced, and the frequency of the flexible direct-current partitioned alternating-current power grid is prevented from entering a dangerous interval.
Owner:CHINA ELECTRIC POWER RESEARCH INSTITUTE CO LTD +1

Rydberg atom electromagnetic signal detection device based on correlated photon coincidence measurement

The invention provides a Rydberg atomic electromagnetic signal detection device based on correlated photon coincidence measurement, and the device comprises a correlated photon source assembly which is used for enabling single-polarization and frequency-stable laser to generate polarization orthogonal correlated photon pairs; the Rydberg atom preparation system is in communication connection with the associated photon source assembly, and associated photon pairs emitted by the associated photon source assembly enter the Rydberg atom preparation system; the correlation detection assembly is in communication connection with the Rydberg atom preparation system and is used for counting transmission photons of the EIT-AT split transmission spectrum signals, and when the difference value between the reference photon arrival time and the transmission photon arrival time is within a preset range, the EIT-AT split transmission spectrum signals are regarded as coincidence events and coincidence counts are recorded. According to the invention, the problem of low sensitivity caused by the defects of optical readout noise, weak off-resonance field response, sensitive temperature drift vibration environment and the like in the prior art is solved.
Owner:BEIJING KEWEI QUANTUM TECHNOLOGY CO LTD +1