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222 results about "Super low frequency" patented technology

Super low frequency (SLF) is the ITU designation for electromagnetic waves (radio waves) in the frequency range between 30 hertz and 300 hertz. They have corresponding wavelengths of 10,000 to 1,000 kilometers. This frequency range includes the frequencies of AC power grids (50 hertz and 60 hertz). Another conflicting designation which includes this frequency range is Extremely Low Frequency (ELF), which in some contexts refers to all frequencies up to 300 hertz.

Ocean-ionized layer ultralow-frequency electromagnetic target detection simulation method based on ADI-FDTD and SIBC

The invention discloses an ocean-ionized layer ultralow-frequency electromagnetic target detection simulation method based on ADI-FDTD and SIBC, and belongs to the field of computational electromagnetics. The ocean-ionized layer ultralow-frequency electromagnetic target detection simulation method comprises the following steps: introducing a frequency domain surface impedance boundary condition SIBC into an ADI-FDTD model; the ocean-ionosphere simulation model is used for carrying out ocean-ionosphere ultra-low frequency electromagnetic wave attenuation analysis on the ocean-ionosphere ultra-low frequency electromagnetic wave attenuation. According to the method, the frequency domain surface impedance boundary condition (SIBC) is combined with the ADI-FDTD method for the first time, so that the calculation space for analyzing the influence of the seabed on electromagnetic wave propagation is reduced. The calculation requirement is obviously reduced, and the efficiency is improved. In addition, the SIBC model based on the ADI-FDTD method can be used for simulating the scattering effect of electromagnetic waves on a high-conductivity and low-conductivity area interface.
Owner:ANHUI UNIV +1

Ultralow frequency sensor

The ultralow frequency sensor comprises a vibration detection unit, a power supply voltage stabilization unit and a signal conditioning unit, the power supply voltage stabilization unit is provided with a low dropout linear voltage regulator U20, a voltage converter U19 and a negative voltage regulator U21, and the low dropout linear voltage regulator U20 stabilizes an external power supply as a positive power supply VCC; the voltage converter U19 is used for converting positive voltage of an external power supply into negative voltage and outputting stable negative power supply VEE through the negative voltage stabilizer; the positive power supply VCC and the negative power supply VEE supply power to the signal conditioning unit; the signal conditioning unit comprises a high common mode rejection differential amplifier, a differential-to-single-ended amplifier, a band-pass filter and a differential output driver, a differential signal output by the vibration detection unit sequentially passes through the high common mode rejection differential amplifier, the differential-to-single-ended amplifier, the band-pass filter and the differential output driver, and then a differential voltage signal is output; the method has the advantages of high stability and reliability and the like.
Owner:WEIHAI SUNFULL GEOPHYSICAL EXPLORATION EQUIP

Folding piezoelectric vibration energy collector

The invention discloses a foldable piezoelectric vibration energy collector, and the collector comprises a cantilever beam which is provided with a fixed end at one end and a free end at the other end; the mass block is located below the cantilever beam, fixedly connected with the free end and used for adjusting the resonant frequency of the cantilever beam; the piezoelectric element is arranged on the cantilever beam; when the cantilever beam vibrates in the vertical direction, the piezoelectric element generates electric energy; the electric energy collecting element is electrically connected with the piezoelectric element and is used for collecting the electric energy; wherein the piezoelectric element comprises a plurality of piezoelectric layers, the plurality of piezoelectric layers are distributed at intervals in the vertical direction and are arranged in parallel, and every two adjacent piezoelectric layers are fixedly connected. Under the condition that a larger mass block or a longer cantilever beam does not need to be arranged, the energy conversion efficiency of the piezoelectric vibration energy collector in an ultralow-frequency vibration environment can be improved, and the miniaturization and wearable requirements of devices or electronic equipment can be met.
Owner:FUDAN UNIVERSITY

Cold atom interference type low-frequency vibration measuring device and measuring method

The invention discloses a cold atom interference type low-frequency vibration measurement device and a measurement method, and solves the problems that the existing cold atom interference gravimeter measurement equipment is limited by the performance of a vibration sensor, the compensation precision is insufficient, timing calibration is needed, and the measurement precision is low. And measurement errors generated by gravity and ultralow-frequency vibration cannot be effectively separated from a measurement result of the cold atom interference gravimeter, namely, decoupling of two measurement parameters is realized, and cold atom interference measurement of low-frequency vibration is realized. The measuring device comprises a Raman laser output system, a vacuum cavity, a sensitive axis converter and a vibration detection reflecting mirror, the Raman laser output system outputs two pieces of Raman laser which have the same polarization state and are both circular polarization states; the low-frequency vibration is transmitted to the liquid crystal phase modulator through the vacuum cavity for polarization state conversion, and then is reflected to the liquid crystal phase modulator or the vibration detection reflector through the polarization splitting prism, so that the interference type low-frequency vibration of the cold atoms is measured, and decoupling of the two is realized.
Owner:XIAN INST OF OPTICS & PRECISION MECHANICS CHINESE ACAD OF SCI

Multi-degree anti-vibration unit

Anti-vibration units are provided for vibration suppression in multiple directions. The anti-vibration units may have an X-shaped structure as part of its support structure. The anti-vibration units can work for ultra-low frequency vibration isolation in three directions in a passive manner. The anti-vibration units can achieve a flexible nonlinear stiffness, which contains zero or quasi-zero stiffness, negative stiffness and positive stiffness. A smooth multi-equilibria state is also achievable. Compared with traditional spring-mass-damper (SMD) and typical QZS systems, the provided anti-vibration units can have an enhanced QZS range of larger stroke with guaranteed loading capacity, and can also achieve a lower resonant frequency with a lower resonant peak. At least some embodiments of the anti-vibration units may include a new and innovative arrangement of components that enables a more compact design than typical anti-vibration systems.
Owner:CITY UNIVERSITY OF HONG KONG

Collaborative optimization method of mixed water electrolysis hydrogen production system considering seasonal wind and light fluctuation

PendingCN121853051AMinimize efficiencyloss minimizationCellsFrequency spectrumThermodynamics
The invention provides a collaborative optimization method of a mixed water electrolysis hydrogen production system considering seasonal wind and light fluctuation. The method comprises the following steps of: analyzing a wind-solar power frequency spectrum by adopting a variational mode decomposition algorithm, and extracting three intrinsic mode function components of ultrahigh frequency, transition frequency band and ultralow frequency; establishing a multi-time-scale collaborative optimization framework comprising a seasonal scheduling layer, an intra-day optimization layer and a real-time control layer; the ultra-low frequency component is distributed to an alkaline electrolytic bath, and the ultra-high frequency component is distributed to a proton exchange membrane electrolytic bath; an electric-thermal-life multi-field coupling efficiency optimization model is constructed, and multi-objective optimization of efficiency maximization and life loss and operation cost minimization is achieved; and an equipment switching critical point calculation method based on an efficiency curve second derivative and a gradient protection strategy are adopted. The method can effectively improve the adaptability of the system to seasonal fluctuation, the operation economy and the service life of equipment.
Owner:POWERCHINA HUADONG ENG CORP LTD

Ultra-low frequency passive self-adaptive tuning vibration absorber based on string-mass system

The invention relates to the technical field of vibration control, and particularly provides an ultralow-frequency passive self-adaptive tuning vibration absorber based on a string-mass system, which comprises a mechanical sensing assembly, a mechanical driving assembly, a mechanical transmission assembly and a tuning vibration absorption assembly which are arranged on a target structure, the mechanical sensing assembly and the mechanical driving assembly are correspondingly arranged, and the mechanical sensing assembly is used for sensing vibration of a target structure and can generate relative movement; the mechanical driving assembly is connected with the mechanical transmission assembly, and the mechanical driving assembly drives the mechanical transmission assembly to work based on relative motion generated by the mechanical sensing assembly; the mechanical transmission assembly is connected with the tuning vibration absorption assembly. The vibration absorber is wide in application range, compared with an existing self-adaptive tuning vibration absorber, the vibration absorber has the advantages that external power supply driving is not needed, the structure is simple, ultralow-frequency vibration control can be achieved, and effective control over broadband even multi-order modal vibration is achieved through a pure mechanical structure.
Owner:CENT SOUTH UNIV

Signal automatic patrol and abnormity intelligent analysis method and device based on centralized control center

The invention provides a signal automatic patrol and abnormity intelligent analysis method and device based on a centralized control center. By constructing a patrol logic control mechanism and combining real-time data acquisition and operation trend analysis, abnormal states and potential fault symptoms occurring in the operation process of the power equipment are identified, periodic or real-time analysis is performed on the operation condition of a target object, and a patrol report and an abnormal grade division result are automatically generated. The method can achieve the intelligent recognition and response of ultralow frequency oscillation, signal fluctuation and other characteristic problems in new power system scenes such as new energy access, facilitates the improvement of the intelligent level of operation monitoring of a centralized control center, and improves the early warning capability of equipment faults and the accident response efficiency. And the operation risk and the system disturbance caused by monitoring omission are avoided.
Owner:HUANENG CLEAN ENERGY RES INST +1

Magnetic suspension type mechanical damping device for ultra-low-frequency vertical vortex-induced vibration of ultra-large-span bridge girder

The invention provides a magnetic levitation type mechanical damping device for ultra-low-frequency vertical vortex-induced vibration of a super-large-span bridge girder, and belongs to the field of low-frequency structure vertical vibration control. The device comprises a mounting base, a top connecting plate, a spring device, a mass block, a magnetic force compensation unit, a damping device and a plurality of guide devices, the multiple guide devices are installed between the installation base and the top connecting plate, the mass blocks are installed on the peripheries of the multiple guide devices, the magnetic force compensation units are installed on the peripheries of the mass blocks, and the mass blocks can vertically move along the guide devices under the action of the magnetic force compensation units. Wherein the spring device and the damping device are vertically arranged between the top connecting plate and the mass block in parallel. The core innovation of the invention lies in providing a magnetic active compensation mechanism, and through a gradient magnetic field with a special configuration, approximately constant upward buoyancy is generated in a TMD vertical motion stroke, so that the mass block is always in a quasi-suspension state, and complete gravity unloading and dynamic tuning separation are realized.
Owner:HARBIN INST OF TECH +1

Power cable insulation state detection system based on ultralow frequency dielectric loss

The invention discloses a power cable insulation state detection system based on ultralow frequency dielectric loss. The system comprises an excitation signal generation module, a signal acquisition and conversion module, a data processing and analysis module, an insulation state evaluation module, a database storage module and a man-machine interaction module. The signal acquisition and conversion module acquires output voltage and current signals and converts analog signals into digital signals; the data processing and analysis module processes signals based on a system identification theory, establishes an equivalent mathematical model, analyzes data, calculates dielectric parameters and provides a basis for evaluation; the insulation state evaluation module combines historical data with a standard threshold value, designs an evaluation algorithm, analyzes dielectric parameter changes, judges the cable insulation problem, sets a parameter alarm mechanism and automatically gives an alarm when the threshold value is exceeded; according to the method, the detection process is optimized based on the identification theory, ultralow frequency key frequency points are covered, the result precision is ensured through mathematical modeling and analysis, the test time is effectively shortened, and the test result accuracy is high.
Owner:SHANGQIU POWER SUPPLY CO OF STATE GRID HANAN ELECTRIC POWER CO

Quasi-zero stiffness vibration isolation device

The utility model discloses a quasi-zero stiffness vibration isolation device which comprises a support, a positive stiffness vibration isolator and a negative stiffness mechanism. The positive stiffness vibration isolator comprises a first support and a second support, a first supporting column is arranged on the first support, and the second support is connected to the first supporting column in a sliding mode. The negative stiffness mechanism comprises an unsprung synchronization unit and a sprung synchronization unit, the unsprung synchronization unit is provided with a second supporting column, and the second supporting column is coaxially located above the first supporting column; an elastic damping structure is arranged between the first support and the second support, and a plurality of negative stiffness elements are arranged between the unsprung synchronization unit and the sprung synchronization unit to form vertical negative stiffness. The utility model relates to the field of vibration reduction and isolation, realizes that the dynamic rigidity is low or is close to zero in a static balance state, solves the difficult problem when a traditional linear vibration isolation system isolates low-frequency or ultralow-frequency vibration, reduces the initial vibration isolation frequency, enlarges the vibration isolation frequency range, and improves the vibration isolation efficiency of the system.
Owner:่ฐญ้”ฆๅฆ‚

A constant-temperature hot-wire anemometer stability margin measurement method based on in-situ open-loop frequency characteristics

This invention relates to a method for measuring the stability margin of a constant-temperature hot-wire anemometer based on in-situ open-loop frequency characteristics, belonging to the field of fluid measurement and automatic control technology. The method disclosed in this invention includes the following steps: S1. Connecting an ultra-low frequency low-pass filter to the closed-loop circuit to form an in-situ open-loop system with a DC closed loop and an AC open loop; S2. Injecting a sweep frequency excitation signal E at the bias circuit. stimu And measure the output response E of the amplifier circuit. a By comparing the amplitude ratio and phase difference of the two, the open-loop frequency response G of the system under actual operating conditions of the hot wire is obtained. open (jฯ‰); S3. According to G open (jฯ‰) Obtain the phase margin of the system and determine its stability. This invention proposes a new method for measuring the stability margin of a constant-temperature hot-wire anemometer, transforming the complex system stability problem into a measurable and analyzable open-loop frequency characteristic stability margin problem, providing a direct and reliable engineering basis for the circuit design of constant-temperature hot-wire anemometers.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

A method for stabilizing the pumping rate of an atomic gyroscope based on a phase-reformatted extended state observer and a power approaching sliding mode control

A kind of atomic gyroscope pumping rate stable composite control method based on phase reshaping extended state observer and power approaching sliding mode control.Aiming at the problems that standard linear extended state observer has steady-state estimation error under the action of ramp disturbance, disturbance estimation phase lag and it is difficult to balance between observation bandwidth improvement and noise sensitivity, a composite corrector composed of lead network and lag network is cascaded at the output end of disturbance estimation of extended state observer, the disturbance estimation channel is shaped in frequency domain, phase lead is provided in mid-frequency band to reduce compensation delay, amplitude lag characteristic is used to suppress high-frequency noise, and parameter constraint design is used to realize zero-error estimation of ramp disturbance;At the same time, a power approaching sliding mode controller is constructed to improve the adaptability to the nonlinear, internal and external coupling and parameter uncertainty of atomic gyroscope system, and the phase reshaping extended state observer is combined to effectively estimate and feed forward compensate the lumped disturbance, so as to improve the stability and accuracy of pumping rate control.The present application can balance dynamic anti-disturbance performance, steady-state control accuracy, convergence speed and noise robustness without significantly improving the observation bandwidth, and is suitable for atomic gyroscope precision control system affected by ultra-low frequency slowly varying disturbance.
Owner:BEIHANG UNIV

A combined polarization ultra-low frequency flexural disk transducer and its preparation method

The present invention relates to a combined polarized ultra-low frequency curved disk transducer and a preparation method thereof. The two transducer components are opposed to each other with the radiation surface facing outward, and an air cavity is provided between the two transducer components. A connecting cable is provided for the two transducer components, and a combined polarization component is provided for any of the transducer components. The present invention combines tangential polarization with thickness polarization. On the basis of conventional thickness polarization, tangential polarization is added to compensate for the vibration displacement at the outer position to obtain a better vibration mode and a larger vibration displacement. By changing the distribution of the piezoelectric elements, the equivalent distribution space of the active driving material is increased. While reducing the resonant frequency of the curved disk transducer, it has a higher transmission voltage response and improves the transmission capability of the transducer. A new implementation method of tangential polarization is proposed to solve the short circuit problem between the element and the metal plate, ensure the adaptability of the vibration mode between the materials, and make the entire transducer have a better vibration mode.
Owner:THE 715TH RES INST OF CHINA SHIPBUILDING IND CORP

A cable insulation aging evaluation method based on high-voltage frequency domain dielectric response characteristic quantity

The application provides a cable insulation aging evaluation method based on high-voltage frequency domain dielectric response characteristic quantity, under the condition that the insulation electric field intensity is 0.5kV / mm-1kV / mm, an ultralow frequency sweep test signal is applied to the measured cable under three different voltages, and the dielectric loss tangent value frequency domain response curve corresponding to each voltage level is obtained; at least two dielectric characteristic quantities are calculated based on the frequency domain response curve, the dielectric characteristic quantities include a first characteristic quantity representing the discrete degree of the dielectric loss tangent value under different voltages, and a second characteristic quantity representing the frequency domain integral characteristic of the dielectric loss tangent value under the highest test voltage; based on a preset correlation evaluation model taking the cable insulation mechanical performance aging index as a benchmark, the insulation health state score of the measured cable is calculated by combining the dielectric characteristic quantities, and the insulation aging state is determined according to the health state score.
Owner:STATE GRID FUJIAN ELECTRIC POWER RES INST +1

Ultralow frequency conduction acoustic system based on reverse installation and sapphire reflection structure

The invention discloses an ultra-low frequency conduction acoustic system based on reverse installation and a sapphire reflection structure, and belongs to the field of audio acoustics, the ultra-low frequency conduction acoustic system comprises a moving coil unit, the sapphire reflection structure and a sound tube, the moving coil unit is reversely installed on the inner side of an earphone surface cover, and a vibrating diaphragm faces the direction away from a sound outlet; sound waves are reflected to the reflecting surface of the stone surface cover of the sapphire reflecting structure through the rear cavity and then are transmitted to the sound outlet through the sound tube; the surface cover of the sapphire reflection structure is of a customized special-shaped structure, is accurately matched with the reflection angle of the rear cavity, and has optical-grade surface smoothness; the moving coil unit is combined with a plurality of moving iron units and static units, and the moving iron units and the static units adopt a forward sound wave conduction mode; the reverse sound wave path is prolonged and reflected by the high-hardness sapphire, and the low-frequency quantity sense is sufficient and distinct in hierarchy; an independent low-frequency sound path can be realized without increasing the volume of the earphone; low frequency and medium-high frequency are physically isolated, and mutual interference is reduced.
Owner:้™ˆ้นคๆ–‡

Navigation at ultra low to high frequencies

A system and method include transmitting a signal according to a set of frequencies. A frequency range associated with the set of frequencies is from about 300 Hz to about 30 MHz. The system and method include sensing an electromagnetic field based on transmitting the signal according to the set of frequencies and determining a distortion in association with sensing the electromagnetic field. The system and method include identifying frequencies at which the magnitude of the distortion is less than the threshold value. The system and method include transmitting the signal according to one or more of the identified frequencies and providing navigation information associated with an environment in response to transmitting the signal.
Owner:MEDTRONIC NAVIGATION INC

Cable insulation state evaluation method based on rapid ultralow frequency dielectric response

The invention discloses a cable insulation state evaluation method based on rapid ultralow frequency dielectric response, comprising the following steps: applying excitation voltage to a cable to obtain an ultralow frequency dielectric spectrum and a U-I hysteresis curve; extracting a characteristic quantity representing the insulation aging of the cable as a criterion for distinguishing the insulation aging type of the cable; respectively setting related index quantities of different cable insulation aging types; constructing an evaluation index system; determining the subjective weight and objective weight of each index in the evaluation index system by adopting an analytic hierarchy process and an entropy weight method respectively, and carrying out combined weighting to determine a combined weight; performing logarithmic correction on the combined weight; constructing a scoring model; evaluating the insulation state of the cable based on a scoring model to obtain an operation state scoring result of the cable; the operation condition of the cable line can be accurately mastered, the operation and maintenance cost is reduced, the test and evaluation time is effectively saved, stable operation of the power cable is ensured, the line failure rate is reduced, and indirect benefits are generated.
Owner:SHANGQIU POWER SUPPLY CO OF STATE GRID HANAN ELECTRIC POWER CO

Magnetic bar coil and laminated ultralow-frequency high-voltage generator

The utility model provides a magnetic bar coil and a laminated ultra-low-frequency high-voltage generator, and relates to the technical field of electron and high-voltage measurement. The winding structure of the coil on the periphery of the magnetic bar is that the two ends are densely wound and the middle is sparsely wound; the periphery of the magnetic bar wound with the coil is sleeved with an insulating tube; the magnetic bar is connected with a plurality of high-voltage lamination units of the lamination type booster in a magnetic field coupling mode. The coil is wound on the periphery of the magnetic bar according to the structure that the two ends are densely wound and the middle is sparsely wound, so that the magnetic flux of the whole body of the magnetic bar is equal, the voltage uniformity of each high-voltage laminated unit is improved, the ultralow-frequency high-voltage generator magnetic bar coil can stably and reliably work, and the high-voltage laminated units are prevented from being damaged due to overvoltage.
Owner:JINAN FANHUA ELECTRIC CO LTD

Vibration isolation device and gravitational acceleration measuring instrument

The invention relates to a vibration isolation device and a gravitational acceleration measuring instrument. The vibration isolation device comprises a primary vibration isolation module and a secondary vibration isolation module. The primary vibration isolation module comprises two fixing structures arranged in the gravity direction in a spaced mode and a floating body structure located between the two fixing structures. The two fixed structures are respectively provided with a first permanent magnet so as to generate a magnetic field between the two fixed structures, and the floating body structure is provided with a second permanent magnet so as to enable the floating body structure to suspend in the magnetic field; the secondary vibration isolation module comprises a displacement measuring unit and an adjusting unit, the displacement measuring unit is used for measuring relative movement information between the fixed structure and the floating body structure, and the adjusting unit is used for adjusting relative displacement between the fixed structure and the floating body structure according to the relative movement information. According to the scheme, the vibration isolation device has a long local oscillation period and has a good inhibition effect on ultralow-frequency vibration.
Owner:TSINGHUA UNIVERSITY

A forming and assembling method of an ultra-low frequency kicker model cavity

The application provides a forming and assembling method of an ultralow-frequency kicker model cavity, and aims at solving the technical problems that a large-diameter copper pipe cannot be directly wound outside an insulating support body made of polytetrafluoroethylene material by a high-temperature heating method, and a large-diameter copper coil cannot be accurately inserted into a slot during forming and assembling of an existing ultralow-frequency kicker model cavity. The application first completes preparation of the large-diameter copper coil by means of a tool, and then sequentially inserts the insulating support body designed as a split structure into the large-diameter copper coil. Meanwhile, the large-diameter copper coil is fixed on the insulating support body by a clamp, the resilience of the large-diameter copper coil is effectively controlled, accurate nesting and fixing of the insulating support body and the large-diameter copper coil are realized, and the accuracy of the resonance frequency of the ultralow-frequency kicker model cavity is ensured. The forming and assembling method of the ultralow-frequency kicker model cavity is convenient, has high reliability, and can accurately realize the target frequency of the ultralow-frequency kicker model cavity.
Owner:NORTHWEST INST OF NUCLEAR TECH

Deep ground medical first-aid digital twinning method and system based on environmental physiological coupling algorithm

The invention discloses a deep ground medical first-aid digital twinning method based on an environmental physiological coupling algorithm. The method comprises the following steps: data acquisition and digital twinning modeling; matching first-aid knowledge; generating an intelligent first-aid scheme; and scheme execution and real-time feedback: pushing the scheme to a deep ground rescue terminal through ultralow frequency communication and Beidou short message double links, receiving execution state feedback in real time, updating the digital twin model, and dynamically adjusting the scheme according to environment and physiological data changes to form closed-loop management. The method has the advantages that the environment and physiology coupling algorithm conducts collaborative modeling through multiple parameters such as temperature, pressure, gas concentration and humidity, the limitation of traditional single parameter correlation is broken through, and the comprehensive influence of the deep complex environment on core physiological indexes such as the heart rate, blood oxygen and body temperature of the human body can be dynamically and accurately reflected; the problem that in an existing scheme, the environment scene is disjointed with the human physiological state is effectively solved, and it is ensured that the first-aid scheme can meet the real physiological needs of trapped people.
Owner:YUNLONG LAKE LAB OF DEEP UNDERGROUND SCI & ENG +1

Broadband power grid oscillation monitoring and alarm methods, systems, equipment and storage media

This invention belongs to the field of power automation and discloses a method, system, device, and storage medium for monitoring and alarming broadband oscillations in power grids. It includes acquiring the oscillation monitoring type and oscillation monitoring data from oscillation monitoring points; and obtaining oscillation monitoring alarm results based on the oscillation monitoring data using the oscillation monitoring judgment method corresponding to the oscillation monitoring type. Different oscillation monitoring judgment methods are used for different oscillation monitoring types. For ultra-low frequency or low frequency oscillations, a combination of time-domain analysis, FFT algorithm, and Prony algorithm is used; for subsynchronous oscillations, a combination of time-domain analysis and FFT algorithm is used; and for sub / supersynchronous or medium-high frequency oscillations, a master-slave combined oscillation monitoring judgment method is used. This effectively solves the problem of misanalysis caused by frequency aliasing in data window selection and data analysis resampling using the pure Prony algorithm, and improves alarm efficiency by enhancing the effectiveness of the Prony algorithm calculation.
Owner:CHINA ELECTRIC POWER RESEARCH INSTITUTE CO LTD +1

Parameter design method of ultra-low frequency tuning lever mass inertia damper

The present application relates to bridge damping technical field, specifically to a kind of super low frequency tuning lever mass inertial mass damper parameter design method, the damper includes: lever, mass, spring and inertial mass mechanism.Lever middle part is rotatably arranged on the structure to be damped, and lever is divided into power arm and resistance arm;Mass is arranged on power arm;Spring one end is connected with resistance arm, and the other end is connected with the structure to be damped;Inertial mass mechanism includes: arc rack, rotating shaft, flywheel and gear;Rotating shaft is rotatably connected with power arm;Flywheel is arranged on rotating shaft;Gear is arranged on rotating shaft, arc rack is fixedly arranged, and cooperates with gear, power arm swings, gear rotates relative to arc rack, and drives flywheel to rotate.This scheme can solve the problem that the elongation and the amount of TMD spring are increased in the prior art by using super low frequency TMD scheme, the installation space of TMD is limited, and the use cost of TMD is greatly increased, and the influence of TMD self weight on bridge structure.
Owner:CHINA RAILWAY MAJOR BRIDGE ENG GRP CO LTD +1

Method, device and equipment for suppressing ultra-low frequency oscillation of power system and storage medium

Embodiments of the present application disclose a power system ultra-low frequency oscillation suppression method, device, equipment and storage medium, the method comprises: acquiring the frequency signal data of the power system and the rotor speed of each wind turbine generator collected by the synchronous phasor measurement device; using the oscillation frequency and the rotor speed of each wind turbine generator to determine whether each wind turbine generator enters the system frequency ultra-low frequency oscillation suppression mode; if any wind turbine generator enters the system frequency ultra-low frequency oscillation suppression mode, then correct the active output reference power of any target wind turbine generator entering the system frequency ultra-low frequency oscillation suppression mode according to the oscillation frequency and amplitude, and realize the suppression of the system frequency ultra-low frequency oscillation. The present application fully considers the flexible control potential of wind power frequency, can realize the active participation of wind power in system frequency ultra-low frequency oscillation suppression, improve system damping and reduce system ultra-low frequency oscillation risk, fully tap the potential of wind power frequency stability control and improve system operation stability.
Owner:YUNNAN POWER GRID CO LTD ELECTRIC POWER RES INST

Low-energy-consumption ultralow-frequency variable-frequency pulsating type hydraulic fatigue test device

The invention provides a low-energy-consumption ultralow-frequency variable-frequency pulsating type hydraulic fatigue test device. The low-energy-consumption ultralow-frequency variable-frequency pulsating type hydraulic fatigue test device mainly comprises a pulsating hydraulic station, an electrical control system, an actuator and a test loading frame. According to the test device, an electric-mechanical-hydraulic energy conversion system is adopted, and the performance characteristics of low energy consumption, low frequency and stable operation are realized through combined application of an inertia flywheel and a gear pair. The testing machine can run for a long time without water cooling, the energy consumption is only one twentieth of that of an electro-hydraulic servo fatigue testing system of the same specification, the running frequency can be as low as 0.1 Hz, and the testing machine can be applied to low-frequency large-amplitude fatigue life testing of large parts, building structural members and full-scale test pieces.
Owner:TIANJIN UNIV +1

Coal mine rock burst disaster acoustoelectric monitoring device based on 5G communication

The utility model discloses a coal mine rock burst disaster acoustoelectric monitoring device based on 5G communication, which comprises an electromagnetic radiation antenna, an acoustic emission sensor, a microseismic sensor, an ultralow frequency sensor, a temperature sensor and an acoustoelectric monitoring device host, the electromagnetic radiation antenna, the acoustic emission sensor, the microseismic sensor, the ultralow frequency sensor and the temperature sensor are connected with the acoustoelectric monitoring device host, and collected data are processed by the acoustoelectric monitoring device host and then sent to a ground server database through a 5G network. Electromagnetic radiation signals, acoustic emission signals, micro-seismic signals, ultralow-frequency signals, temperature signals and measuring point position image data which are generated by deformation and fracture of coal and rock mass are monitored in a movable mode, the monitoring data are directly transmitted to a ground server database from the underground in time through a 5G communication module, and it is ensured that the data are safe and reliable; and the method can be used for risk assessment and forecast monitoring of coal mine rock burst disasters.
Owner:XUZHOU FUAN TECH

An integrated test method and system for cable oscillating ultra-low frequency withstand voltage and partial discharge

The present invention discloses a method and system for integrated testing of oscillating ultra-low frequency withstand voltage and partial discharge of cables, which relates to the technical field of distribution network cable detection, and includes: applying an oscillating ultra-low frequency voltage signal to the cable under test; the oscillating ultra-low frequency voltage signal is optimized and adjusted through a manifold learning algorithm and used as a common excitation source for withstand voltage test, dielectric loss detection and partial discharge detection; obtaining the voltage signal and current signal of the cable under test under the excitation of the oscillating ultra-low frequency voltage signal, analyzing the deviation degree of the voltage signal and current signal from the pre-built feature manifold, and extracting the dielectric loss feature signal and partial discharge pulse signal; calculating the dielectric loss parameter based on the dielectric loss feature signal, determining the partial discharge position based on the partial discharge pulse signal, and generating a cable insulation status diagnosis report according to the dielectric loss parameter and partial discharge position. The present invention improves the cable testing efficiency, reduces the equipment burden and testing time, realizes the comprehensive evaluation of the insulation status and accurate fault location, and provides a scientific basis for the preventive maintenance of the power system.
Owner:SHANDONG CHANGYOU POWER ENG CO LTD

Controllable power supply electric furnace equipment device for valuable metal recovery

The utility model relates to a controllable power supply electric furnace equipment device for valuable metal recovery, a furnace body comprises a furnace shell and a furnace cover fixedly arranged at the top end of the furnace shell, an electrode assembly comprises a graphite electrode and a bottom electrode, the graphite electrode is arranged above the furnace cover, the bottom electrode is arranged at the bottom in the furnace shell, and the graphite electrode is arranged above the furnace cover. The bottom electrode is insulated from the furnace shell, and a conducting circuit of the bottom electrode is connected to the short net system. The power supply is an ultralow-frequency controllable polarity power supply device, the input of the power supply is at the primary end of the transformer system, the output of the power supply is the output ends of the power supply cabinet system and the reactor system, and the power supply is output to the short network system. The device can be used for the technical process of gathering valuable metals in the melting smelting of solid waste residues, can deeply recover the valuable metals, improves the recovery rate of the metals, reasonably utilizes the heat of high-temperature liquid slag, directly reduces the metals in the slag, improves the recovery ratio and purity of the metals in the solid waste residues, and reduces the production cost. And meanwhile, solid waste residues obtained after metal extraction are subjected to slag system reconstruction, so that the activity is improved, and the quality is stable.
Owner:XIAN NEW QINDONG METALLURGICAL TECH CO LTD +1

An intelligent electromagnetic antibacterial and scale removal system and method for a power plant condenser

The present invention relates to the technical field of power plant condensers, and discloses an intelligent electromagnetic antibacterial and scale removal system and method for a power plant condenser, including: acquiring data information and water flow parameters on the cooling water pipeline of the condenser; determining the number of turns of the coil of the electromagnetic antibacterial component based on the data information on the cooling water pipeline; and determining the electromagnetic wave frequency emitted by the electromagnetic antibacterial component based on the water flow parameters. By emitting ultra-low frequency electromagnetic waves with an appropriate frequency, the present invention excites water molecules to generate resonance, preventing scale formation and corrosion on the heat exchange tubes of the condenser.
Owner:HUANENG SUZHOU THERMAL POWER CO LTD