166 results about "Super low frequency" patented technology

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.

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.

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.

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.

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.

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.

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.

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.

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 (jω); S3. According to G open (jω) 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The invention provides a hardware detection method and device for a digital output interface of a motion control system, and the method comprises the steps: triggering the motion control system to enter a pre-configured test mode, and generating an ultralow-frequency periodic signal; the ultralow-frequency periodic signal is output to the target signal pin of the digital output interface without changing related parameters of a normal working mode of the motion control system, and the duration time of a single level in the ultralow-frequency periodic signal is greater than or equal to the preset response time of the universal meter, so that the target signal pin can be measured through the universal meter, and the measurement accuracy is improved. Therefore, the hardware detection of the digital output interface is realized through a simple universal meter, the cost is reduced, and the universal meter is convenient to carry and is more suitable for on-site detection and troubleshooting.

The application discloses a torsional negative stiffness vibration isolation device based on pre-tensioned springs and belongs to the technical field of vibration isolation devices.The vibration isolation device can normally transmit the rated torsional motion of a system, reduces the torsional dynamic stiffness of the system, lowers the natural frequency, realizes the torsional vibration isolation of shaft system components under low-frequency and ultralow-frequency bands, and has a good vibration isolation effect.Two ends of two connecting rod devices are connected in a hinged manner on an inner part and corresponding sliding blocks respectively, the two sliding blocks are limited in displacement directions through sliding grooves fixed on the inner side of an outer part, and elastic elements generate acting forces on the two sliding blocks and apply torsional moments on the inner part through the two connecting rod devices.The application introduces a negative stiffness device, reduces the torsional dynamic stiffness of a shaft system structure, lowers the natural frequency of the system in the torsional direction, and realizes the vibration isolation function under low-frequency and ultralow-frequency bands.

The application discloses a compliant variable stiffness curved beam supporting ultra-low frequency vibration isolation device, which comprises a main frame, a main connecting rod movably arranged in the main frame, and a negative stiffness mechanism and a positive stiffness mechanism coupled in parallel to the main connecting rod, wherein the negative stiffness mechanism with nonlinear negative stiffness is sleeved on the main connecting rod, the positive stiffness mechanism with nonlinear positive stiffness is fixed at one end on the main frame and is fixedly connected at the other end with the main connecting rod, the nonlinear positive stiffness mechanism is used for modulating the nonlinear negative stiffness mechanism, and the high static stiffness and low dynamic stiffness characteristics are realized. The application adopts the arc-shaped beam with double-end clamping to provide the nonlinear negative stiffness, adopts the spiral-shaped beam to provide the nonlinear positive stiffness and the guiding function, and adopts the parallel arc-shaped beam and spiral-shaped beam to realize the high static stiffness and low dynamic stiffness characteristics. The stiffness of the vibration isolation device only needs to be modulated by adjusting the coupling connection relationship of the positive stiffness mechanism and the negative stiffness mechanism, the configuration parameters of the elastic elements do not need to be changed or the elements do not need to be replaced, the stiffness modulation is flexible, and the ultra-low dynamic stiffness can be easily realized. The vibration isolation device adopts the compliant design, is convenient to assemble, has no motion gap and contact friction limitation, and can realize the ultra-low frequency vibration isolation.

The invention relates to a dynamic frequency change tracking live detection device, which belongs to the technical field of power system experiments and comprises a main control module, a double-differential electric field coupling module, an ultrahigh-resistance steady-state acquisition module, a differential amplification and signal conditioning module and a steady-state judgment module. The double-differential electric field coupling module is used for forming more than two groups of coupling potential signals with different spatial positions under the action of an electrostatic field in the space around the measured conductor; the ultrahigh-resistance steady-state acquisition module is connected with the double-differential electric field coupling module; the differential amplification and signal conditioning module is connected with the ultrahigh-resistance steady-state acquisition module; and the steady state discrimination module is connected with the differential amplification and signal conditioning module. According to the invention, the ultrahigh-resistance steady-state maintaining structure is introduced into the electric field coupling end to suppress the discharge of the coupling charge, so that the coupling potential formed by the space electrostatic field under the ultralow-frequency and quasi-static conditions can stably exist, and the reliable identification of the direct-current and ultralow-frequency charged state is realized.

The present application relates to the technical field of hydroelectric generating set operation, and discloses a hydroelectric generating set ultra-low frequency oscillation suppression method, device, equipment and medium, the present application first obtains rotor motion data sets of multiple hydroelectric generating sets, can comprehensively understand the operation state of each hydroelectric generating set. Secondly, the mechanical power of the wide range of speed change rate can be fitted through the target mechanical power relationship, which can more accurately represent the mechanical power of the hydroelectric generating set. Further, the oscillation energy of the speed regulation system can be more accurately calculated by combining the oscillation energy relationship of the speed regulation controller. Finally, multiple hydroelectric generating sets can be quickly determined which hydroelectric generating sets have ultra-low frequency oscillation problems by sorting multiple hydroelectric generating sets according to multiple oscillation energy values. Finally, the energy storage is used to suppress the ultra-low frequency oscillation of the hydroelectric generating set, which can effectively solve the coordination problem of the primary frequency modulation performance and the ultra-low frequency oscillation suppression of the hydroelectric generating set, and provides a new technical means for solving the ultra-low frequency oscillation problem.

The invention provides a pumping unit control system and method, and relates to the technical field of oil field oil extraction equipment control. According to the system, a control module is connected with a high-precision sampling module and a high-frequency power module; the high-precision sampling module is used for sampling the oil pumping unit based on the oversampling rate to obtain sampling data; the control module is used for determining state data of the oil pumping unit based on the sampling data and switching between an open-loop control mode and a closed-loop control mode based on the state data; and the high-frequency power module is used for starting a motor of the oil pumping unit in a closed-loop control mode. The high-precision sampling module and the high-frequency power module are cooperated to work, so that the working performance of the oil pumping unit is fundamentally improved, flexible starting of the oil pumping unit can be realized, heavy-load starting can be realized at ultra-low frequency, and the oil pumping unit can be effectively controlled on the basis that the original unit installed power of the oil pumping unit is not increased or even reduced. And strong instantaneous overload capacity is provided for the oil pumping unit, so that the oil pumping unit can reliably cope with various special working conditions.

The application discloses an embedded vertical NPR surface wave isolation resonator and isolation barrier, and belongs to the technical field of earthquake protection. The NPR surface wave isolation resonator comprises a top concrete cap, a first NPR frame layer, a steel column, a second NPR frame layer, a bottom concrete cap and a concrete packaging box. The first NPR frame layer and the second NPR frame layer are both spliced from a negative Poisson's ratio solid structure with a negative Poisson's ratio effect of a rubber material and are embedded between the concrete cap and the steel column. The application has the advantages that the traditional earthquake metamaterial isolation barrier can not only realize an ultra-wide and ultra-low frequency band gap but also ensure the durability and strength of the resonator structure as a whole when the resonator as a whole is subjected to stress vibration deformation, and when isolating seismic waves, the negative Poisson's ratio solid structure plays a role in energy absorption and energy dissipation, and the resonator itself has the characteristics of local resonance, thereby being capable of coping with the ultra-low frequency band gap generated by the ultra-low frequency seismic wave.

The application relates to a cable partial moisture evaluation method combining VLF dielectric loss and wide-frequency impedance spectrum testing, which comprises the following steps: S1, obtaining the dielectric loss change rate, dielectric loss stability over time and dielectric loss average value of the measured cable by using VLF; S2, obtaining a time-domain positioning spectrum by using BIS, and calculating the polarity deviation of each reflection peak; S3, calculating the moisture risk index of the measured cable; S4, establishing a partial moisture evaluation model; S5, inputting the data of S1-S3 into the partial moisture evaluation model of S4, calculating a moisture state evaluation value, and evaluating the partial moisture degree of the measured cable. The application comprehensively considers the indexes obtained by the VLF dielectric loss test (VLF) and the wide-frequency impedance spectrum method (BIS), combines the cable characteristics, establishes a new cable partial moisture evaluation model, and improves the accuracy of the cable partial moisture state evaluation.