33 results about "Harmonic phase" patented technology

The invention provides a real-time dynamic harmonic detection method and system for a traction power supply system, and relates to the technical field of harmonic detection, and the detection method comprises the following steps: collecting a voltage signal of the traction power supply system in real time, and dynamically tracking fundamental frequency fluctuation through a phase-locked loop technology; dynamically adjusting the data window length of FFT analysis; dynamically adjusting a frequency spectrum calculation kernel of the FFT; carrying out linear compensation on the detected harmonic phase; taking the preliminarily detected harmonic parameter as an initial value, and iteratively updating the harmonic parameter until convergence by minimizing a signal reconstruction error; dynamically adjusting a sampling interval according to the fundamental frequency fluctuation, and carrying out anti-aliasing processing by adopting a filter with a variable cut-off frequency; and constructing a matrix model containing a fundamental frequency fluctuation parameter, and calculating a real harmonic parameter through a least square method. According to the method, the detection defect of the fixed window FFT during frequency fluctuation can be systematically solved, and high-reliability real-time data support is provided for harmonic resonance suppression of the electrified railway.

The invention discloses a power grid cross-correlation harmonic suppression method, device and equipment and a storage medium, and the method comprises the steps: carrying out the wavelet packet decomposition of a subnet electric signal, and obtaining the harmonic component of a subnet at each frequency band; calculating the harmonic phase difference between the subnets according to the cross-correlation function between the harmonic components of the subnets and the topological impedance matrix, and calculating the total harmonic distortion rate according to the harmonic components of the subnets in the frequency bands; constructing a harmonic transfer equation according to the harmonic phase difference between the subnets and the equivalent output impedance of the inverter so as to calculate the harmonic responsibility proportion of the subnets; solving the double-layer game model based on the total harmonic distortion rate, the reference value of the total harmonic distortion rate and the harmonic responsibility proportion of the subnet, and obtaining the output of the governance equipment; and inputting the output of the treatment equipment into the fuzzy controller to obtain the impedance adjusting quantity of the subnet, and adjusting the virtual impedance according to the impedance adjusting quantity to update the harmonic backflow path. According to the invention, harmonic suppression among multiple subgrids during high-permeability distributed grid connection is realized, and the operation stability of the power grid is improved.

The invention discloses a method, a system, equipment and a medium based on a multi-composite ultrasonic penetration technology, and the method comprises the steps: generating high-frequency fundamental ultrasonic waves through a piezoelectric transducer array, and adjusting the frequency range to match the acoustic impedance characteristic of target soil; first, second and third harmonics are generated through the induction of a nonlinear medium in the fundamental wave propagation process, the phases of the harmonics are adjusted to realize coherent superposition, and the fundamental wave and the first, second and third harmonics are guided into a composite waveguide device for focusing and delay compensation to form a high-energy composite wave beam; a pulse interval is adjusted by adopting an intermittent emission strategy so as to inhibit energy attenuation in the soil; reflected wave spectrum components are monitored through an embedded acoustic sensor array, and driving parameters are dynamically adjusted; and residual ultrasonic energy is captured and fed back to a driving circuit to form a closed-loop energy utilization system. By integrating multi-order harmonic resonance and a dynamic frequency tuning technology, efficient transmission and deep penetration of ultrasonic energy in a complex medium are realized.

The present application discloses a method, apparatus, device and storage medium for cross-correlated harmonic control in power grids. The method includes: performing wavelet packet decomposition on subnet electrical signals to obtain the harmonic components of the subnet in each frequency band; calculating the harmonic phase difference between subnets based on the cross-correlation function and topological impedance matrix between the harmonic components of each subnet, and calculating the total harmonic distortion rate based on the harmonic components of the subnet in each frequency band; constructing a harmonic transfer equation based on the harmonic phase difference between subnets and the equivalent output impedance of the inverter to calculate the harmonic responsibility ratio of the subnet; solving a two-layer game model based on the total harmonic distortion rate and its reference value and the harmonic responsibility ratio of the subnet to obtain the output of the control equipment; inputting the output of the control equipment into the fuzzy controller to obtain the impedance adjustment amount of the subnet, and adjusting the virtual impedance according to the impedance adjustment amount to update the harmonic return path. The present application realizes the harmonic control between multiple subnets during high-penetration distributed grid connection, thereby improving the stability of power grid operation.

The invention relates to the technical field of power monitoring, in particular to an online monitoring method and system for a power control cabinet. The method comprises the following steps: acquiring a time domain signal, tracking a fundamental wave frequency, adjusting a sampling window, and performing Fourier transform to obtain a harmonic amplitude and a phase; harmonic waves are divided into harmonic wave correlation groups according to association rules, harmonic wave phase consistency coefficients are calculated to weight the total energy in the groups, and weighted harmonic wave energy is obtained; total inter-harmonic energy is calculated, and an inter-harmonic structure factor is obtained based on the spectral entropy. And acquiring a real-time load rate and a change rate, and calculating a synchronous change coefficient and a load factor. And summing the weighted harmonic energy and the corrected inter-harmonic energy to obtain total distortion energy, and obtaining a comprehensive distortion index according to the total distortion energy. According to the scheme, the structured inter-harmonics possibly caused by the early failure of the equipment can be found earlier, and the requirements of early warning and predictive maintenance are met.

The invention discloses a cascaded H-bridge frequency converter harmonic wave selective elimination method based on a space voltage vector in a CAES, and the method comprises the steps: collecting system operation data, and constructing a real-time monitoring data set; analyzing harmonic time-domain characteristics and a phase relation, and calculating a critical phase difference matrix; reconstructing an optimized space voltage vector, and calculating a switching time sequence perturbation quantity; generating a phase locking control instruction, and optimizing an H-bridge driving signal; and monitoring system output and dynamically adjusting control parameters. The sensitivity of resonance harmonic waves to the phase relation is revealed, the harmonic wave phase is accurately controlled through the microsecond-level switching time sequence, the harmonic wave amplification effect under the resonance condition is effectively restrained, and the system stability and the electric energy quality are improved.

The invention discloses a bearing fault acoustic detection method and system based on fractional harmonic phase-locked amplification, and the method comprises the steps: obtaining an acoustic signal of a target motor, measuring the shaft rotation frequency of a motor shaft in real time, synchronizing the shaft rotation frequency to a fractional phase-locked loop, and carrying out the calculation of a bearing fault characteristic frequency according to the geometric parameters of a bearing, the bearing fault characteristic frequency is a non-integer multiple of the shaft rotation frequency, generating a reference signal synchronous with the bearing fault characteristic frequency through a fractional phase-locked loop, and performing phase sensitive detection on the obtained acoustic signal and the generated reference signal by using a phase-locked amplifier, specifically, performing orthogonal demodulation on the acoustic signal and the reference signal, and performing phase sensitive detection on the obtained acoustic signal and the reference signal. The method comprises the following steps: generating an in-phase component and an orthogonal component, extracting a direct-current component through low-pass filtering, calculating to obtain a vibration amplitude and phase information corresponding to a bearing fault characteristic frequency, and judging the type and severity of a bearing fault according to the comparison between the vibration amplitude and a preset baseline, the harmonic consistency and the phase stability.

The invention relates to the technical field of unmanned aerial vehicle nondestructive testing, and discloses an unmanned aerial vehicle precision part rapid detection system based on multi-sensor fusion. Low-frequency harmonic vibration excitation is applied through a micro vibration excitation module, and a phase offset auxiliary harmonic signal is generated in combination with a multi-harmonic phase synchronous modulation module; and the defect response of the precision part is amplified. The multi-sensor array synchronously collects vibration, optical and thermal response data, and data calibration is carried out through the sensor array self-calibration network. And the defect pattern library pre-matching engine matches the current detection data with the historical defect pattern. And the fusion processing unit performs weighted fusion on the multi-modal detection data, adjusts detection parameters according to a detection result through a closed-loop feedback loop, and triggers iterative detection. According to the invention, low-frequency harmonic vibration excitation is applied through the micro vibration excitation module, and the multi-harmonic phase synchronous modulation module is combined to superpose auxiliary harmonic signals of phase deviation, so that the identification capability of micro defects is improved.

The invention discloses a TDLAS (Tunable Diode Laser Absorption Spectroscopy)-based gas concentration and temperature dual-parameter detection method and device, and the detection method comprises the following steps: 1, obtaining an optical signal passing through an absorption cell filled with gas to be detected, and converting the obtained optical signal into a digital signal to be detected; step 2, obtaining a fundamental frequency harmonic phase signal according to the digital signal to be measured and the two fundamental frequency reference signals; obtaining a second harmonic signal according to the digital signal to be measured and the two paths of frequency doubling reference signals; and 3, establishing an equation set of the fundamental frequency harmonic phase signal, the second harmonic signal and the gas concentration and temperature, and solving the equation set to obtain the gas concentration and temperature. According to the invention, the gas concentration and temperature signals are obtained through a simple method, the method can be used for replacing a lock-in amplifier, and the cost of a detection device and the system complexity can be effectively reduced.

The present invention provides a method for compressing a signal, the method comprising: obtaining a main signal via a signal recording module; modeling a model signal of the main signal via a processor by: obtaining a sampled signal via the processor; obtaining a windowed signal via the processor; and extracting, via the processor: a fundamental frequency waveform having a fundamental magnitude and a fundamental phase; and at least one harmonic frequency waveform having a harmonic magnitude and a harmonic phase; wherein the model signal comprises the fundamental frequency waveform and the at least one harmonic frequency waveform; calculating, via the processor, an error signal between a reconstructed signal and the main signal; determining, via the processor, an optimal gain according to at least: an averaging step providing an average, a predefined threshold, and a scaling signal, wherein the scaling signal is a historical error signal scaled by iteratively: averaging a difference between the error signal and the scaling signal, wherein the optimal gain comprises a predefined gain when the average satisfies the predefined threshold; determining, via the processor, an index from a residual signal by: determining the residual signal; vector quantizing the residual signal; and indexing the vector quantized residual signal; synthesizing, via the processor, a compressed signal, wherein the compressed signal comprises: the fundamental phase; the fundamental magnitude; the harmonic phase; the harmonic magnitude the optimal gain; the index. Thus, the compression method preferably overcomes problems associated with current compression techniques, and provides a suitable technique for compressing a signal that can be used to infer a type of load on a circuit.

The present invention provides a real-time dynamic harmonic detection method and system for a traction power supply system, which relates to the technical field of harmonic detection. The detection method includes the following steps: collecting voltage signals of the traction power supply system in real time, and dynamically tracking the fundamental frequency fluctuation through a phase-locked loop technology; dynamically adjusting the data window length of the FFT analysis; dynamically adjusting the spectrum calculation kernel of the FFT; and linearly compensating the detected harmonic phase; taking the preliminarily detected harmonic parameters as initial values, and iteratively updating the harmonic parameters until convergence by minimizing the signal reconstruction error; dynamically adjusting the sampling interval according to the fundamental frequency fluctuation, and performing anti-aliasing processing by using a filter with a variable cut-off frequency; constructing a matrix model containing fundamental frequency fluctuation parameters, and calculating the true harmonic parameters by using the least squares method. The method of the present invention can systematically solve the detection defects of the fixed-window FFT in the case of frequency fluctuation, and provides high-reliability real-time data support for the harmonic resonance suppression of electrified railways.

The application discloses a ship shaft generator system and battery coordination harmonic suppression method and system, and belongs to the technical field of ship power system harmonic suppression; the method comprises the following steps: synchronously collecting three-phase current signals of the shaft generator system and charging and discharging current signals of the battery system, and generating a harmonic characteristic data set; extracting a harmonic phase offset characteristic vector between the shaft generator system and the battery system based on the data set; determining the harmonic phase reversal direction that needs to be compensated by the battery system according to the offset characteristic vector; generating a phase reversal compensation logic matrix based on the harmonic phase reversal direction; generating a dynamic harmonic compensation instruction for driving the battery system according to the matrix; and executing the instruction through a bidirectional converter, so that the battery system outputs an active compensation current opposite to the harmonic phase of the shaft generator system. The system comprises corresponding function modules. The application can track the dynamic drift of the harmonic phase caused by the ship swing in real time, adaptively generate an optimal compensation strategy, and significantly improve the harmonic suppression efficiency and the power grid stability.

The invention provides a harmonic phasor estimation method and a harmonic phasor estimation system. The harmonic phasor estimation method comprises the following steps: extracting the center frequency of each component of a signal based on a matrix pencil method; performing complex demodulation on each component according to the center frequency of each component; and obtaining a baseband phasor of each component according to a filtering result of each component demodulated by the complex number based on the FIR filter of the flat-top window. The method can be used for phasor measurement of fundamental waves and harmonic waves, and is simple, wide in application range and high in estimation precision.

The invention relates to harmonic current emission level estimation, in particular to a distributed multi-source harmonic current emission level estimation method under an under-quantitative measurement condition, which comprises the following steps of: synchronously acquiring a concerned frequency harmonic voltage phasor of a concerned bus and a concerned frequency harmonic current phasor of a concerned harmonic source incoming line provided with a monitoring device in a concerned time period; the collected harmonic phasor time sequence data are preprocessed; converting the preprocessed harmonic phasor time sequence data from a time domain form into a frequency domain form; calculating harmonic transfer impedance between the concerned bus and the concerned harmonic source; estimating a harmonic emission current of the harmonic source of interest; according to the technical scheme provided by the invention, the defect that the emission level of the distributed multi-source harmonic current is difficult to accurately estimate under the conditions that the harmonic sources are distributed at multiple points and the number of monitoring devices is insufficient in the prior art can be effectively overcome.

The present application relates to a kind of adaptive band optimization chorus sound separation method and system based on harmonic maintenance, first, the signal is collected by microphone array and time delay compensation and multi-channel time-frequency transformation are carried out;Sound source spatial positioning and initial band division are carried out using MUSIC algorithm;Using the greedy optimization strategy, the band boundary is dynamically adjusted and optimized by maximizing the objective function including signal-to-noise ratio and harmonic integrity measure;Then, the fundamental frequency is obtained by harmonic analysis and detection, and the time-varying harmonic trajectory is tracked across frames by Viterbi algorithm;On this basis, combined with MVDR beam forming and the introduction of harmonic maintenance factor, enhanced time-frequency representation is obtained by soft time-frequency mask;Finally, inverse short-time Fourier transform time-domain reconstruction and synchronous harmonic phase are carried out.The present application realizes the accurate allocation of voice part spectrum, effectively reduces the overlap interference, protects the overtone column of human voice while accurately separating, significantly improves the timbre fidelity and naturalness of separated voice part.

The application relates to a cable insulation safety evaluation method and system based on harmonic data preprocessing, and the method comprises the following steps: collecting voltage or current data of a cable to be detected; according to the periodic characteristics of harmonics, harmonic data is updated after reaching a preset fixed time each time, the process of the harmonic data updating comprises the following steps: extracting harmonics of the voltage or current data through a wave trap, and compensating the harmonic phase by using a repetitive predictive controller to obtain extracted harmonics; multiplying the extracted harmonics by an amplitude gain module to compensate the harmonic amplitude and obtain optimized harmonics; subtracting the optimized harmonics from the original voltage or current data to obtain fault data; performing traveling wave decoupling on the fault data, and judging the fault type and fault distance of the cable according to the traveling wave signal obtained through decoupling. Compared with the prior art, the application realizes rapid evaluation of cable insulation safety and rapid and accurate positioning when the insulation is damaged.

The application provides a multi-harmonic superposition control method and device for a synchrotron. The method comprises: obtaining a current cavity fundamental wave signal, a current cavity harmonic wave signal and a current beam signal; calculating a first phase difference between the current cavity fundamental wave signal and the current beam signal based on the current cavity fundamental wave signal and the current beam signal; performing phase compensation on the current cavity fundamental wave signal based on the first phase difference and a first preset phase difference to obtain a first fundamental wave signal; calculating a second phase difference between a harmonic wave signal corresponding to the current cavity fundamental wave signal and the current cavity harmonic wave signal based on the current cavity fundamental wave signal and the current cavity harmonic wave signal; performing phase compensation on the current cavity harmonic wave signal based on the second phase difference and a second preset phase difference to obtain a first harmonic wave signal; and synthesizing a radio frequency signal based on the first fundamental wave signal and the first harmonic wave signal. Through the application, the phase deviation of each harmonic of the radio frequency signal is reduced, and the phase of the radio frequency signal is accurately controlled.

The invention provides a multi-harmonic-source composite responsibility division method and system, and relates to the field of electric energy quality, and the method comprises the steps: obtaining the bus superposition harmonic voltage of a multi-harmonic source and the harmonic current of each feeder line; according to the Euclidean distance between the harmonic voltage and each harmonic current, the correlation between the harmonic voltage and the harmonic current is judged, and a harmonic correlation feeder line is selected; according to a Thevenin equivalent circuit established for a harmonic-related feeder line, obtaining a grid-connected point harmonic voltage, and calculating a harmonic impedance and a background harmonic voltage; based on the harmonic impedance and the background harmonic voltage, calculating the harmonic source voltage responsibility of each feeder; according to the method, the feeder lines related to the main harmonic waves are obtained through correlation analysis, then harmonic wave responsibility division is carried out, the method is more suitable for a power grid containing a direct-current line, and repeated calculation of different harmonic wave sources is avoided.

The application relates to the field of electric digital processing, in particular to a power grid harmonic identification method and system based on deep learning, which comprises the following steps: inputting processed voltage data and current data into an LSTM model, outputting predicted data of voltage and current, obtaining voltage sequences and current sequences after processing, performing window division on the voltage sequences and the current sequences, obtaining local waveform differences in combination with amplitude spectra of corresponding windows, obtaining harmonic amplitude sequences by the amplitudes of the frequency corresponding to odd harmonics in the window sequence amplitude spectrum, obtaining harmonic amplitude change sequences after processing, obtaining harmonic similarity in combination with the local waveform differences, obtaining the harmonic contribution degree of a load feeder by using the harmonic amplitude sequences of different odd harmonics in the common coupling point voltage sequence to obtain the integrated harmonic similarity of the recognition significance degree, and sorting the harmonic contribution degrees and selecting a preset proportion of harmonic contribution degrees that meet preset conditions. The application has the effects of accurately locating a harmonic source and improving harmonic source identification accuracy.

The present application discloses an audio separation method, apparatus, device, storage medium and program product, which belongs to the field of audio processing technology. The method comprises: obtaining the audio to be separated, the audio to be separated includes at least two tracks; obtaining the time domain features and texture features of the audio to be separated, the time domain features and texture features are used to characterize the harmonic correlation and harmonic continuity of the audio to be separated respectively; according to the time domain features and texture features, obtaining the spectral features corresponding to n track sets respectively, the spectral features are used to characterize the frequency and amplitude information of the track sets, each track set includes a combination of several tracks in the audio to be separated; according to the spectral features corresponding to the n track sets respectively, n corresponding audio files are generated. The present application provides an audio separation method with good separation effect, which reduces the computational load of the equipment during the audio separation process and improves the speed of audio separation by generating the spectral features corresponding to the track sets respectively through the time domain features and texture features.

The invention relates to the field of electric digital processing, in particular to a power grid harmonic recognition method and system based on deep learning, and the method comprises the steps: processing collected voltage data and current data, inputting the processed data into an LSTM model, outputting the prediction data of voltage and current, obtaining a voltage sequence and a current sequence after processing, carrying out the window division, and obtaining a current sequence; obtaining a local waveform difference by combining the amplitude spectrum of the corresponding window, obtaining a harmonic amplitude sequence through the amplitude of the frequency corresponding to the odd harmonic in the amplitude spectrum of the window sequence, obtaining a harmonic amplitude change sequence after processing, and obtaining harmonic similarity by combining the local waveform difference; the harmonic amplitude sequences of different odd harmonics in the common coupling point voltage sequence are utilized to obtain the harmonic contribution degrees of the load feeder line by integrating the significance degree and the harmonic similarity, the harmonic contribution degrees are sorted, and the harmonic contribution degrees with the preset proportion are selected to meet the preset condition. The method has the advantages that the harmonic source can be accurately positioned, and the harmonic source identification accuracy is improved.

The application discloses a bearing fault acoustic detection method and system based on fractional harmonic phase-locked amplification, acoustics signals of a target motor are acquired, the shaft rotation frequency of the motor shaft is measured in real time, and is synchronized to a fractional phase-locked loop; according to the geometric parameters of the bearing, the bearing fault characteristic frequency is calculated, the bearing fault characteristic frequency is a non-integer multiple of the shaft rotation frequency, a reference signal synchronized to the bearing fault characteristic frequency is generated through the fractional phase-locked loop, and the acquired acoustics signals and the generated reference signal are detected in a phase-sensitive manner through a phase-locked amplifier; specifically, the acoustics signals and the reference signal are quadrature demodulated to generate in-phase components and quadrature components, direct current components are extracted through low-pass filtering, and then the vibration amplitude and phase information corresponding to the bearing fault characteristic frequency are calculated; according to the comparison between the vibration amplitude and a preset baseline, harmonic consistency and phase stability, the bearing fault type and severity are determined.

The invention discloses a method for identifying first third-order harmonic waves of unbalanced mass of a hemispherical resonator based on vibration excitation, and belongs to the field of parameter identification of hemispherical resonators. The method solves the problems of low leveling efficiency and precision caused by difficult data identification and long measurement time of an existing method for identifying the first third-order harmonic waves of the unbalanced mass. Under vibration excitation, the vibration amplitude and the standing wave azimuth angle of the hemispherical harmonic oscillator are associated with the first-order harmonic and the third-order harmonic of the unbalanced mass; under vibration excitation, the vibration amplitude and the standing wave azimuth angle of the hemispherical harmonic oscillator are associated with the second-order harmonic of the unbalanced mass. And the first three-order harmonic amplitudes and azimuth angles are solved by constructing a corresponding coupling relationship. The method is mainly used for identifying the first third-order harmonic waves of the unbalanced mass of the hemispherical harmonic oscillator.

The invention discloses a multi-harmonic combination and accurate output electric energy meter calibrating device and method, and relates to the technical field of electric energy meter detection. Comprising a harmonic generation module used for generating a harmonic signal; the phase control module is used for adjusting the phase of the generated harmonic signal to obtain an adjusted harmonic signal; the power amplification module is used for amplifying the adjusted harmonic signal to obtain an amplified harmonic signal; the signal monitoring and feedback module is used for monitoring parameters of the amplified harmonic signals in real time and feeding back the monitored parameters; and the upper computer control module is used for receiving the input verification parameters and controlling the harmonic generation module, the phase control module and the power amplification module according to the verification parameters and the feedback parameters. Through the advanced harmonic generation circuit and the accurate phase control module, high accuracy of harmonic content and harmonic phase output is realized.

A method and device for identifying DC component users based on the relationship between the fundamental and harmonic phase angles. The power quality analysis module in the IoT power meter reads the fundamental amplitude and phase angle, and the amplitude and phase angle of each harmonic of the secondary current of the current transformer; when the amplitude of each harmonic is less than the amplitude threshold, it is determined to be a non-DC component user. When there is any harmonic amplitude that is not less than the amplitude threshold, for each harmonic that is not less than the amplitude threshold, based on the trigonometric function theorem, the phase angle of each harmonic is processed as a positive value using the period of each harmonic; and the ratio of each harmonic phase angle processed as a positive value to the corresponding harmonic order is calculated; the difference between the ratio and the fundamental frequency impedance angle of the current transformer is calculated as the calculated fundamental phase angle corresponding to each harmonic; when the error between the calculated fundamental phase angle corresponding to each harmonic and the fundamental phase angle is less than the error threshold, it is determined to be a DC component user.

This invention discloses a sound source identification method and system based on the nonlinear harmonic phase conjugation method (PCD). The method involves acquiring the sound pressure gradient time-domain signal of the target sound source using a pre-constructed planar microphone array. After performing a fast Fourier transform on the sound pressure gradient time-domain signal to obtain the sound pressure gradient frequency-domain signal, a sound pressure gradient frequency-domain signal that meets the resolution requirements for reconstructing the sound field is selected as the higher harmonic sound pressure gradient signal. The sound field of the target sound source is reconstructed by establishing the phase conjugation method and the higher harmonic sound pressure gradient signal using dipole source emission based on the sound pressure gradient time-domain signal. This allows personnel to identify the target sound source through the reconstructed sound field. This method improves the resolution of sound field reconstruction by using the nonlinear harmonic phase conjugation method for sound source identification and is not limited by the near-field limitation of evanescent waves.

The application discloses a kind of based on geometric error comprehensive measurement and unified parameterization hemispherical resonator vibration performance evaluation method, it is related to optical element processing field, to solve the lack of comprehensive evaluation method of hemispherical resonator vibration performance based on multiple source geometric error in prior art.The technical points include: measuring hemispherical resonator multi-source data, convert measurement data to unified coordinate system and unified circumferential reference;Further error separation is carried out to measurement data, obtain the circumferential distribution geometric error and position size geometric error of hemispherical resonator;Circumferential harmonic decomposition is carried out to circumferential distribution geometric error, obtain each error circumferential harmonic amplitude, circumferential harmonic phase and global circumferential harmonic complex amplitude, and position size geometric error is combined, and the geometric error parameter set of hemispherical resonator is constructed;Geometric structure is constructed to hemispherical resonator by geometric error parameter set, and the vibration performance of hemispherical resonator is carried out finite element analysis.

The invention discloses a non-linear metasurface capable of generating frequency-doubled harmonic waves and dynamically modulating harmonic wave phases, which is formed by periodically arranging a plurality of frequency-doubled harmonic wave phase reconfigurable units, and each frequency-doubled harmonic wave phase reconfigurable unit can efficiently convert a space incident fundamental frequency signal into a second harmonic wave radiated to the space. And the phase of the second harmonic is independently and dynamically regulated and controlled. Benefited from the independent regulation and control capability of each unit on the phase of the second harmonic, the metasurface can flexibly control the radiation direction of the second harmonic, and can also take the second harmonic as a carrier wave to modulate digital information on the carrier wave and realize wireless transmission. Compared with an existing harmonic wave nonlinear metamaterial, the metamaterial has the advantages of being low in profile, high in harmonic wave generation efficiency and capable of dynamically controlling harmonic waves.

The present invention provides a motor vibration suppression control method, device and equipment, relating to the technical field of motor control. The method includes: determining the harmonic phase corresponding to the minimum vibration noise based on the fundamental wave amplitude; determining the harmonic amplitude corresponding to the minimum vibration noise based on the fundamental wave phase; using the harmonic phase and the harmonic amplitude as the target harmonic current command to control the motor to generate a vibration suppression torque so as to suppress the torque fluctuation caused by the harmonic current.

The present invention discloses a harmonic selective elimination method for a cascaded H-bridge frequency converter based on space voltage vectors in CAES, including: collecting system operation data to construct a real-time monitoring data set; analyzing the harmonic time-domain characteristics and phase relationships to calculate a critical phase difference matrix; reconstructing and optimizing the space voltage vectors to calculate the switching timing perturbation amount; generating a phase-locked control instruction to optimize the H-bridge drive signal; monitoring the system output and dynamically adjusting the control parameters. The present invention reveals the sensitivity of resonant harmonics to phase relationships, precisely controls the harmonic phases through microsecond-level switching timing, effectively suppresses the harmonic amplification effect under resonant conditions, and improves the system stability and power quality.