25 results about "Harmonic resonance" patented technology

The invention discloses a wind turbine generator impeller anomaly detection method and system based on sound vibration signal identification. According to the method, firstly, impeller response is collected through a microphone / vibration sensor, and a Mel spectrogram is generated; then, a Teager-Kaiser energy operator and self-correlation analysis are utilized, and under the condition of not depending on a rotating speed signal, the rotating period of the impeller is recognized, and frequency spectrum segmentation is carried out; calculating a cross-period Mel frequency spectrum dynamic deviation, and normalizing the cross-period Mel frequency spectrum dynamic deviation through an amplitude correction coefficient related to the rotating speed; generating a periodic coherent energy diagram by adopting an improved structural similarity algorithm; performing filtering enhancement by using a harmonic resonance template, performing morphological deconstruction and parameterization on an abnormal region in the graph, and extracting geometric features; and finally, calculating a comprehensive abnormal score based on the multi-dimensional features and realizing automatic early warning. According to the method, the problems of variable working condition interference and rotating speed dependence are effectively solved, and accurate and stable detection of early abnormality of the impeller can be realized.

The invention relates to a frequency conversion and moving blade combined control method, device and equipment of an induced draft fan and a medium. Comprising the steps that performance parameters and structure parameters of a target induced draft fan are obtained, the target induced draft fan is simulated based on the parameters, and an initial frequency conversion-moving blade combined operation strategy is generated; a resonance rotating speed prohibition interval of the target induced draft fan is determined, and a final frequency conversion-moving blade combined operation strategy is generated based on the initial frequency conversion-moving blade combined operation strategy and the resonance rotating speed prohibition interval; generating a rotating speed-moving blade opening mapping table based on the strategy and a first preset frequency conversion-moving blade coupling operation area of the target induced draft fan; and based on the first preset frequency conversion-moving blade coupling operation area, the second preset frequency conversion-moving blade coupling operation area, the preset multi-mode adjusting rule and the rotating speed-moving blade opening mapping table, frequency conversion and moving blade combined control is conducted on the target induced draft fan. Therefore, the problem that in the prior art, on the premise that the safety of an induced draft fan device body is guaranteed (frequency conversion harmonic resonance is avoided), the operation efficiency in the full working condition range cannot be optimized is solved.

The invention belongs to the technical field of regional power grid electric energy quality treatment, and discloses a cross-power-grid harmonic resonance suppression method, system and device and a medium, and the method comprises the steps: deploying an active filter, and executing local harmonic treatment; on the basis of a local harmonic suppression result, the operation state of the active filter is evaluated, the residual capacity of the flexible resources in the regional power grid is called, and a cooperative harmonic suppression mechanism for cooperative work of the active filter and the flexible resources is constructed; and synchronously executing local harmonic suppression and collaborative harmonic suppression mechanisms, monitoring the total harmonic distortion rate of the regional power grid in real time, performing iterative optimization adjustment on the installation position and capacity of the active filter by using a particle swarm optimization algorithm, and outputting an optimal suppression scheme. According to the invention, through optimizing the harmonic suppression strategy, the total harmonic distortion rate of the power system is reduced, so that the harmonic suppression effect is improved; and a chance constraint method is adopted to ensure that the method has good robustness and adaptability under different power grid operation conditions.

The invention relates to a compressor torque compensation method and variable frequency air conditioning equipment. The method comprises the steps that vibration acceleration frequency spectrums of a compressor in multiple directions under adjacent operation frequencies are obtained, the vibration acceleration frequency spectrums comprise vibration acceleration amplitude values under a fundamental wave frequency and a harmonic wave frequency, and according to the vibration acceleration amplitude value change trend of the fundamental wave frequency or the harmonic wave frequency under the adjacent operation frequencies, the vibration acceleration frequency spectrums of the compressor in multiple directions are obtained; and judging whether the compressor generates fundamental wave resonance or harmonic wave resonance at the current operation frequency, determining a torque compensation strategy according to the resonance mode and the resonance direction under the condition of judging that the compressor generates fundamental wave resonance or harmonic wave resonance at the current operation frequency, and executing the torque compensation strategy in a resonance frequency range containing the current operation frequency, and torque compensation current is determined, and torque compensation is conducted on the compressor according to the torque compensation current. By the adoption of the method, directional and accurate vibration suppression can be achieved, and the compensation effect is remarkably improved.

The invention provides a power system resonance suppression method and device, equipment and a storage medium, and relates to the technical field of power quality analysis and control. The method comprises the following steps: acquiring electrical signals of a plurality of nodes in a power system, and identifying a source node which generates harmonic resonance currently and a corresponding resonant frequency based on the electrical signals; a load redistribution scheme is generated with the aim of destroying the resonance condition of the source node, the scheme is used for transferring at least one load under the source node to other nodes so as to change the system impedance of the source node, and the system impedance is equal to the parallel equivalent value of the impedance of all the loads under the source node; a load redistribution scheme is performed to suppress harmonic resonance. Resonance suppression can be realized only by optimizing the existing network load distribution, the system transformation cost is remarkably reduced, the additional operation loss is reduced, the instability risk is controlled, meanwhile, the advantages of rapid response, high adaptability and the like are achieved, and effective technical support is provided for constructing a safe and flexible novel power system.

The invention discloses an ammeter relay resonance fault detection method and system based on harmonic analysis, and relates to the field of electrical variable measurement, and the method comprises the steps: obtaining a current signal and a voltage signal, and carrying out the preprocessing, and obtaining a current analysis signal and a power grid harmonic spectrum of a current period; quantifying the resonance risk of the power grid based on the power grid harmonic spectrum to obtain a resonance sensitivity index of the power grid in the current period; presetting a candidate wavelet basis set, and obtaining a time-frequency focusing capability evaluation index and a task suitability index of each candidate wavelet basis in the set; based on the three indexes, constructing a dynamic comprehensive cost function and selecting an optimal wavelet basis; and performing wavelet packet decomposition on the current analysis signal based on the optimal wavelet basis, extracting fault features, and identifying and judging the current working state of the relay. According to the method, adaptive selection of the wavelet basis can be realized, and the problems of inaccurate fault feature extraction, high false alarm rate and unreasonable computing resource utilization of an existing detection method are solved.

The embodiment of the invention relates to the technical field of harmonic resonance suppression of an energy storage converter, and provides a harmonic resonance suppression method and system for a network construction type energy storage converter, which abandons the traditional thought of relying on fixed parameters, and perceives the stability of a grid-connected system online in real time through a non-intrusive resonance state observer. The resonance state observer can accurately identify the frequency and the damping ratio of the most unstable resonance mode in the current system to form a real-time diagnosis report, and based on the real-time diagnosis report, a virtual impedance controller with optimal parameters is further dynamically synthesized, so that the real-time diagnosis report is obtained. The center frequency of the virtual impedance can accurately lock the identified resonant frequency, and the damping strength of the virtual impedance is adaptively adjusted according to the severity of resonance (namely the deterioration degree of the damping ratio), so that the problem of invalidation or deterioration of suppression caused by the time-varying of the impedance of the power grid and the drifting of a resonance point in the traditional method is solved; and the stability of the converter in a dynamic change power grid environment is ensured.

The invention provides a ship valve electric device control system and a construction method thereof, and belongs to the technical field of ship valve control. According to the electric device control system, a frameless torque motor is used as a driving unit, and parameter identification, self-adaptive control, smooth switching and safety protection units are integrated, so that motor parameter drift and inverter nonlinear disturbance can be compensated in real time; according to the control method, a linear active-disturbance-rejection self-adaptive control framework is constructed through dead-beat direct torque flux linkage control and an extended Kalman filter algorithm, a full-rank identification model is established through time-sharing injection of current, accurate parameter identification is achieved in combination with an improved particle swarm algorithm, a harmonic resonance suppression and ramp function switching strategy is adopted, and the control precision is improved. And the torque ripple and the mode switching impact are reduced. The problems that a traditional ship valve device is low in torque density, narrow in speed regulation range and weak in anti-interference capacity are solved, the special working condition requirements of low-speed heavy load, high-speed position regulation and the like of a ship valve are met, control precision is high, and stability and reliability are high.

The present application relates to the technical field of neuroacoustics, in particular to a personalized brainwave induction audio generation method and system, comprising: step S1, extracting multi-dimensional features of an input audio signal, the extracted dimensions including at least time domain features, frequency domain features, pitch features, emotion features and complexity features; step S2, based on the multi-dimensional features extracted in step S1, parallelly calculating parameters of four neuroacoustic induction mechanisms; step S3, according to the features obtained in step S1 and the four-mechanism parameters obtained in step S2, fusing signals corresponding to the four mechanisms through a weight distribution strategy and a signal synthesis formula to generate a final brainwave induction audio. The present application has the advantages that: four mechanisms of rhythm synchronization, harmonic resonance, neural oscillation coupling and binaural beat effect are fused, mechanism parameters are dynamically adjusted through analysis of music features, and efficient personalized brainwave induction is realized.

Synchronization within a wireless power transmission system is used to ensure proper transfer of power. An example wireless power system includes a wireless power transmitter and a wireless power receiver, wherein the wireless power transmitter comprises a transmitter controller. The wireless power receiver comprises filter circuitry configured to receive an input signal from the wireless power transmitter, identify a harmonic signal of the input signal, and generate a filtered signal. The wireless power receiver also comprises converter circuitry configured to convert the filtered signal to an output signal, and a receiver controller configured to control the converter circuitry, wherein the receiver controller is synchronized with the transmitter controller based on the harmonic signal identified by the filter circuitry.

The invention relates to the technical field of smart power grids, and discloses a harmonic resonance-based impedance remodeling low-frequency alternating-current power transmission and transformation system, which comprises a data synchronization module, a harmonic analysis module, a vibration frequency calculation module, an impedance characteristic determination module, an impedance adjustment instruction generation module and an impedance remodeling module, acquiring a real-time current signal and a real-time voltage signal in a low-frequency alternating-current power transmission process, and performing phase synchronization on the real-time current signal and the real-time voltage signal to obtain power transmission data; extracting each harmonic component in the power transmission data, and determining a dominant harmonic component in the low-frequency alternating-current power transmission process; determining the initial resonant frequency of the low-frequency alternating-current power transmission process; determining the current impedance characteristic of the low-frequency alternating-current power transmission process, and constructing an impedance adjustment instruction of the low-frequency alternating-current power transmission process to obtain a low-frequency alternating-current power transmission and transformation process after resistance remodeling; the accuracy of low-frequency alternating-current power transmission and transformation can be improved.

The application relates to the technical field of Bluetooth earphone control, and discloses a Bluetooth earphone voice control method, system and equipment based on AI, the method comprising the following steps: acquiring real-time audio and a voice signal, and obtaining frequency distribution characteristics through Fourier transformation; a matched peak position set is obtained through multi-layer convolution operation and peak value detection; a single sound source feature subset is extracted and clustered according to the peak position set, so that a classified sound source group is obtained; a harmonic resonance feature vector is fused and analyzed, a preliminary tuning parameter set and a candidate list are generated, and an optimal set is determined; a dynamic tuning scheme is obtained through smoothing processing and weight adjustment; after the voice signal instruction is matched, the scheme is activated, the real-time audio is adjusted, and an optimized signal is output. The method can realize intelligent real-time audio optimization and multi-frequency adaptive adjustment based on a voice instruction, and improves the sound quality performance and auditory experience of the Bluetooth earphone in different scenes.

The invention belongs to the technical field of regional power grid electric energy quality management, and discloses an offshore wind plant station harmonic resonance suppression method, system and device and a medium, and the method comprises the steps: calling the residual capacity of an offshore wind power access node, carrying out the primary harmonic compensation based on the residual capacity, and carrying out the primary evaluation of a regional power grid after the primary harmonic compensation; if the initial evaluation does not meet the preset suppression requirement, establishing a collaborative suppression mechanism by combining an active filter, performing secondary harmonic compensation by applying the collaborative suppression mechanism, and performing secondary evaluation on the regional power grid after the secondary harmonic compensation; and if the secondary evaluation result still does not meet the preset suppression requirement, performing iterative optimization on the parameter configuration of the active filter and the utilization configuration of the residual capacity by using an improved particle swarm optimization algorithm to obtain an optimal configuration scheme. According to the invention, through cooperative utilization of the residual capacity of the wind power, the number of active filters is reduced, the treatment cost is reduced, and the wind power compensation economy is optimized.

An antenna device and a communication terminal device are provided that can widen the frequency band or support multiple frequency bands without degrading antenna characteristics. The antenna device (100) disclosed herein includes: a first radiating element (11) connected to a feed circuit (30); a second radiating element (12); a first coil (L1) connected to the first radiating element (11); a second coil (L2) connected between the second radiating element (12) and a ground electrode, and electromagnetically coupled to the first coil (L1); and a capacitor (C2) connected in parallel with the second coil (L2), forming a parallel resonant circuit. The resonant frequency of the parallel resonant circuit is a frequency within the frequency band of the fundamental resonance or harmonic resonance of the first radiating element (11).

The invention provides a power distribution network harmonic suppression method and device and a controller, and relates to the technical field of urban power distribution network harmonic resonance suppression. The method comprises the following steps: acquiring an admittance matrix of a target power distribution network, parameters of each harmonic suppression device and voltage distortion rates of each node; establishing a time domain differential state model of each module of each harmonic suppression device according to the parameters of each harmonic suppression device, converting the time domain differential state model into a frequency domain differential state model, and constructing a frequency coupling model of each harmonic suppression device about input and output according to the frequency domain differential state model; and performing optimal planning solution based on the frequency coupling model, the admittance matrix and the voltage distortion rate of each node to obtain optimal operation parameters of each harmonic suppression device. According to the method, the frequency coupling model can be integrated into harmonic treatment optimization of the target power distribution network, and compared with a traditional ideal harmonic source model, the method is more accurate, and the treatment effect is more excellent.

The utility model relates to a particle energy penetrating damp-clearing resonance health-preserving device which comprises a shell, a top cover is fixedly installed on the top of the shell, an LED display screen is arranged on the top of the top cover, a back plate is fixedly installed on the back face of the shell, a handheld groove is formed in the bottom of the shell, a charging base is installed at the bottom of the shell, and the charging base is provided with a power source. Treatment holes are formed in the left side and the right side of the bottom of the shell, a body temperature detection mechanism is arranged at the bottom of the shell, an intelligent control circuit board is fixedly installed in the shell, and a mounting frame is fixedly installed in the shell. According to the particle energy penetrating damp-clearing resonance health preserving device, the collected increased temperature is transmitted to the remote server side through the G / G network for recording and high temperature reminding, detected data can be displayed on the LED display screen, the increased temperature in the health preserving process can be detected in real time, high temperature early warning is carried out, and the health preserving effect is good. And the safety and the practicability of the particle energy penetration dampness-clearing resonance health-preserving device are improved.

The invention belongs to the technical field of electric power systems, and discloses an offshore wind power system harmonic resonance modal analysis method, system and device and a medium, and the method comprises the steps: constructing a small-signal mathematical model of a direct-drive fan based on constant power control, and extracting the equivalent admittance of the direct-drive fan; constructing an offshore wind power system model, converting the model into admittance parameters under a two-phase rotating coordinate system, and constructing a node admittance matrix of the offshore wind power system; constructing a node voltage equation of the offshore wind power system, and performing eigenvalue decomposition on a node admittance matrix in the node voltage equation of the offshore wind power system; and on the basis of the frequency range and the step length, determining a characteristic value and a corresponding modal impedance under each frequency, and positioning a resonance point and a key mode according to the characteristic value and the modal impedance so as to realize harmonic resonance modal analysis of the offshore wind power system. According to the invention, modal analysis can be carried out under the dq coordinate system, and harmonic resonance analysis and key node identification of the wind power system can be realized.

The application discloses a kind of electric meter relay resonance fault detection method and system based on harmonic analysis, it is related to the field of measurement electric variable, method includes: obtaining current signal and voltage signal and pre-processing, obtain the current cycle of current analysis signal and power grid harmonic spectrum;Based on power grid harmonic spectrum, the resonance risk of power grid is quantified, and the resonance sensitivity index of current cycle power grid is obtained;Pre-set candidate wavelet basis set, obtain the time-frequency focusing ability evaluation index and task adaptability index of each candidate wavelet basis in set;Based on three indexes, construct dynamic comprehensive cost function and select optimal wavelet basis;Based on optimal wavelet basis, wavelet packet decomposition is carried out to current analysis signal, and the current working state of relay is extracted fault feature and identified to judge.The application can realize the adaptive selection of wavelet basis, solve the problem that fault feature extraction is not accurate, false positive rate is high, and computing resource is not reasonably utilized in existing detection method.

A front-stator pump-jet propulsion device and fluid analysis method, belonging to the field of underwater propulsion technology, includes: a duct, a hub, and a propulsion assembly. The duct, hub, and propulsion assembly are coaxially arranged, with the hub and propulsion assembly installed inside the duct. The propulsion assembly includes multiple stator blades and multiple rotor blades, with an odd number of stator blades, more stator blades than rotor blades. The stator blades are fixed to the leading edge region of the inner wall of the duct, and the rotor blades are mounted on the hub. The stator blades are located upstream of the rotor blades and form an axially connected series structure, collectively constituting the energy conversion unit in the flow channel inside the duct. This invention, through the combination of an odd number of stator blades and an asymmetric number of rotor blades, effectively suppresses harmonic resonance at the blade passing frequency, reduces the peak noise levels of the shaft frequency and blade frequency, improves the hydrodynamic performance of the pump-jet propulsion device under different operating conditions, reduces the excitation force and noise of the pump-jet propulsion device, and improves the stealth performance of underwater vehicles.

This invention relates to the field of hybrid DC transmission technology, and more particularly to a resonance suppression method, apparatus, electronic device, and medium for hybrid DC transmission systems. The method, based on a resonance suppression circuit, includes: in response to determining that the sending-end suppression branch is currently in effective operation (a first operating state), activating the sending-end suppression branch to make it exhibit low impedance at the target low-frequency harmonic frequency; and in response to determining that the sending-end suppression branch is currently in a malfunctioning second operating state, blocking the resonant current by utilizing the inherent high impedance characteristics of the receiving-end suppression branch at the target low-frequency harmonic frequency. This approach solves the problem that existing resonance suppression schemes struggle to simultaneously prevent harmonic voltage stress concentration near critical receiving-end equipment and eliminate the risk of instantaneous system exposure to resonance due to the failure of a single suppression device, thereby improving the reliability and safety of second-harmonic resonance suppression in hybrid DC transmission systems.

The embodiment of the invention discloses a new energy grid-connected harmonic suppression regulation and control method and device, electronic equipment and a medium. A specific embodiment of the method comprises the following steps: performing variable window Fourier transform on a power instantaneous value sequence set, and then performing impedance compensation to obtain a compensated power harmonic spectrum diagram set; performing critical point identification on the new energy grid-connected power region to obtain a harmonic resonance critical point set; performing early warning grade division on the harmonic resonance critical point set to obtain an early warning grade critical point set; performing harmonic time sequence prediction on the compensated power harmonic spectrogram and the inverter power information to obtain a harmonic prediction amplitude oscillogram; and performing harmonic suppression control on the early warning grade critical point to obtain grid-connected harmonic regulation and control information, and performing equipment regulation and control processing on the power equipment. According to the embodiment, the early warning accuracy of the harmonic resonance risk and the efficiency of suppressing the harmonic resonance can be improved, the equipment delay is reduced, the safety of the new energy grid-connected equipment is improved, and the power loss is reduced.

The invention belongs to the technical field of nano photonics and spectral analysis, and particularly relates to an optimization design method of an enhanced SERS (Surface Enhanced Raman Scattering) substrate and application of the SERS substrate in trace substance detection. The local surface plasmon resonance (LSPR) characteristic of a regular polygon silver nanostructure (3-octagon) is systematically researched through a time domain finite difference (FDTD) method, it is found that the square structure has the optimal electric field enhancement performance (the electric field intensity reaches 7.84 V / m) under the excitation wavelength of 532 nm, and the enhancement mechanism of the square structure is attributed to quadruple symmetric local field distribution and curvature sudden change induced second harmonic resonance. According to the method, the oriented design of the SERS substrate electromagnetic field enhancement effect is realized by taking'edge number selective optimization 'as a core and regulating and controlling the edge number and curvature distribution of the nanostructure for the first time. The method can be widely applied to trace molecule detection in the fields of biomedicine, environmental monitoring and food safety, and has the advantages of high sensitivity, high stability and customizability.

This invention belongs to the field of harmonic analysis technology, and provides a method and system for harmonic resonance analysis considering the location of harmonic sources. It obtains the network topology and component parameters of a power system, constructs the node admittance matrix of the system at a specific frequency, and performs eigenvalue decomposition on the node admittance matrix. Based on modal analysis theory, each element of the node impedance matrix is ​​represented as a superposition of all modal impedances, establishing a mapping relationship between each node impedance and modal impedance, left eigenvector, and right eigenvector. According to the modal superposition expression, an improved modal participation factor considering the location of harmonic sources is constructed and screened to quantify the resonance degree and modal composition of each node in the system, identifying the key resonant nodes and dominant modes of the system. This invention solves the problem of large evaluation deviations of traditional participation factors under complex operating conditions with complex network structures and multiple resonant points, improving the accuracy and applicability of harmonic resonance analysis.

The invention discloses a bionic energy field synthesis system and method based on a red stone needle composite conversion bridge and vascular harmonic targeting. The system comprises an intelligent waveform synthesis engine, a composite transduction and execution module and a multi-mode sensing and feedback module. According to the composite module, a red stone needle-graphene functional layer is combined on a piezoelectric substrate to serve as a core, and a far infrared and broadband mechanical vibration field is cooperatively output under electric driving by utilizing the intrinsic characteristics of materials. The system innovatively takes a measurable blood vessel harmonic resonance state as a target, and dynamically adjusts an output field through double closed-loop control (a physical field loop and a physiological harmonic loop), so that preset physical characteristics can be reproduced, and a physiological system can be effectively guided to be optimized to a healthy state; a bionic energy field which can generate targeted coupling with an in-vivo harmonic resonance system through active synthesis is realized for the first time, normal form upgrading from empirical external treatment to precise biophysical intervention is realized, and a core solution is provided for a new generation of precise and personalized physical treatment equipment.

This invention belongs to the field of metal fittings, specifically relating to a high-speed spindle structure and its transmission components. The spindle includes a spindle with one end closed and an eccentrically positioned circular groove at the other end. A rotor and a plug are housed inside the groove, forming a functional cavity between the inner cavity of the groove and the plug. One side of the functional cavity is filled with asphalt, and the other side is filled with water. This invention achieves adaptive vibration reduction across the entire speed range through an eccentrically mounted rotor and dual-medium damping of asphalt and water, effectively suppressing critical speed resonance and fractional harmonic resonance. It also possesses the advantage of temperature-rise self-adjusting damping, meeting the stable operation requirements of high-speed precision machining.