11 results about "Current spectrum" patented technology

This application discloses a controller heat dissipation interface compensation control method, device, and system, belonging to the field of heat dissipation control technology for servo motors. The method includes: acquiring the trigger signal of the acceleration detection unit; resolving the target interface pressure based on the thermal management target of the power device, and calculating the fundamental amplitude and frequency of the disturbance current; sampling, conditioning, and denoising the bus current, and extracting the dynamic fluctuation component to calculate the pressure coefficient; when the pressure coefficient is less than a preset separation threshold, calculating the disturbance amplitude correction based on a model reference adaptive control algorithm, adding it to the fundamental amplitude of the disturbance current; when the energy of the current spectrum exceeds a preset energy threshold within the first offset frequency range of the structural fundamental frequency, superimposing the second offset frequency onto the fundamental frequency, generating a disturbance current signal, and superimposing it onto the motor's current control signal. This method can quickly compensate for interface contact pressure and transiently suppress the rise in target interface thermal resistance.

This invention discloses a method, system, medium, and device for detecting DC arc faults in photovoltaic systems. The method includes: acquiring current data for each time window in the transmission circuit of the photovoltaic system; performing current spectrum calculation to obtain the corresponding current spectrum vector; calculating the edit distance between the real number sequence of the current time window and the real number sequence of a reference time window according to a set characteristic frequency band, obtaining a distance calculation result; setting a threshold and comparing the distance calculation result with the threshold: if the distance calculation result is greater than the threshold, the current time window is marked as a fault time window; otherwise, it is marked as a normal time window; within N consecutive time windows, if the cumulative number of fault time windows reaches a set number M, a DC arc fault is detected. This invention enables accurate and reliable detection of arc faults in photovoltaic systems.

The present application relates to a kind of laser automatic frequency locking methods based on similarity recognition spectrum, comprising: S1, digital PID feedback controller is to laser output sweep voltage;S2, obtain the spectrum signal of laser output under current sweep voltage;S3, whether there is target spectrum in current spectrum signal based on similarity recognition algorithm is determined, if exists, execute step S4;If target spectrum is not identified, adjust sweep voltage and return to execute step S1;S4, based on the locking point of similarity coefficient peak position determination current characteristic spectrum;S5, after obtaining locking point, based on the frequency locking parameter of locking point determination current characteristic spectrum, control digital PID feedback controller is based on the control amount of the frequency locking parameter and carries out PID control locking.This method can achieve the finding of various spectral characteristic peaks and locking point, wide applicability, small environmental interference and method recognition efficiency is high.

This application discloses an automatic laser phase modulation spectrum screening method, apparatus, device, medium, and product, relating to the laser field. The method includes: acquiring the return light values ​​of an initial spectrum under different laser drive currents; selecting the drive current corresponding to the return light values ​​showing differences among the return light values ​​of different initial spectra as a set current value; changing the initial spectrum and reading the return light value under the current spectrum; the return light value under the current spectrum is obtained by applying the drive current to the set current value; selecting the spectrum with return light values ​​below a first set threshold as the preliminary screening result; selecting the preliminary screening result corresponding to the highest drive current value in the self-pulsation phenomenon as the optimal spectrum; the drive current value of the laser drive current increases from the set current value until the self-pulsation phenomenon of the spectrum in the preliminary screening result appears. This application can reduce the laser output power and screening time for spectrum screening.

The application discloses a zero-crossing breaking control method and system based on arc energy transfer prediction and application in ring network cabinet, and relates to the technical field of zero-crossing breaking. Current data and burning images caused by arc energy due to the decay of current data over time are collected. Through Fourier transform, the current data is converted into a current spectrum diagram, which can more accurately reflect the information of the current. Then, a convolutional neural network is used to detect the state of current change. Using an associative neural network, the burning condition of the surface of the contact is combined with the current data, and association and fusion are performed to obtain an arc correlation feature vector. The change of the arc correlation feature vector at multiple time points can more accurately predict the zero-crossing point.

The application discloses a kind of grid-connected point equivalent grid impedance identification method and equipment using full-power variable-speed pumped storage, medium, it is related to new energy grid performance test technical field.The method comprises: to the voltage command of q axis or d axis of full-power variable-speed pumped storage grid-connected power electronic converter, controllable broadband disturbance signal is superimposed, so that converter includes the disturbance corresponding to controllable broadband disturbance signal in the output to the measured grid-connected point;Voltage and current time domain response data of measured grid-connected point are collected;From the voltage and current time domain response data collected, extract the voltage and current spectrum response data in preset frequency band;Based on the voltage and current spectrum response data in preset frequency band, the equivalent grid impedance of measured grid-connected point is calculated.The present application does not need complex equipment field installation process, also does not need additional development impedance identification device, improves technical economy and implementation convenience.

This invention discloses a method, apparatus, device, and medium for PPG spectrum enhancement based on adaptive weighting. The method includes: performing a Fast Fourier Transform on the PPG signal after removing motion artifacts to generate continuous spectral frame data, and calculating the signal-to-noise ratio (SNR) of the spectral frame data; quantizing the user's current motion level based on the motion acceleration component signal, and dynamically determining the fusion weight between the current spectral frame data and historical spectral frame data based on the calculated SNR of the current spectral frame data; fusing the current spectral frame data and historical spectral frame data using an infinite impulse response recursive weighted accumulation algorithm based on the determined fusion weight between the current spectral frame data and historical spectral frame data to obtain enhanced current spectral frame data; and detecting the user's current heart rate based on the enhanced current spectral frame data. This invention denoises the PPG signal with low computational overhead, improving the accuracy of user heart rate detection.

The application relates to the technical field of telecommunications and Internet of Things, and particularly relates to a multi-protocol communication resource optimization scheduling method for power Internet of Things, which acquires bandwidth demand indexes, power consumption constraint indexes and current spectrum data of a target terminal, quantitatively calculates protocol matching degrees of multiple candidate communication protocols to determine a target communication protocol; constructs an interference evaluation model in combination with a basic noise floor, adjacent frequency band signal strength and frequency offset, optimally selects target spectrum resources; and simultaneously processes multi-terminal competition based on a task priority mechanism, adaptively corrects bandwidth weight coefficients and power consumption weight coefficients in protocol matching degree calculation, and transfers the updated weight coefficients to the next round of scheduling. The application solves the contradiction between high-definition video backhaul bandwidth demand and battery endurance constraint in a power Internet of Things operation site, ensures stable transmission of key services, reduces device energy consumption, improves anti-interference capability, and improves the robustness and stability of the power Internet of Things.

The present invention proposes a method and apparatus for arithmetic encoding a current spectrum coefficient using a prior spectrum coefficient. The prior spectrum coefficient is already encoded, and both the prior spectrum coefficient and the current spectrum coefficient are contained in one or more quantized spectra obtained from quantizing the time-frequency transformation of a video, audio, or voice signal sample value. The method comprises the steps of processing the prior spectrum coefficient, determining a context class which is one of at least two different context classes using the processed prior spectrum coefficient, determining a probability density function using the determined context class and a mapping from at least two different context classes to at least two different probability density functions, and arithmetic encoding the current spectrum coefficient based on the determined probability density function, wherein the step of processing the prior spectrum coefficient includes non-uniformly quantizing the absolute value of the prior spectrum coefficient for use in determining the context class.

This invention discloses an online monitoring method and system for surge arresters, primarily relating to the field of online monitoring technology for power equipment. It includes: synchronously acquiring leakage current, reference voltage, and ambient temperature and humidity; obtaining the leakage current spectrum through analog-to-digital conversion and windowed FFT; determining the fundamental phase from the reference voltage spectrum; decomposing the fundamental leakage current into resistive and capacitive fundamental waves; extracting the resistive fundamental wave amplitude and the third harmonic amplitude; using temperature and humidity to calculate a correction factor to correct the dynamic threshold for moisture alarm; comparing the resistive fundamental wave amplitude with the dynamic threshold, and combining this with the third harmonic growth rate to comprehensively determine whether the surge arrester is damp or the component is abnormal; simultaneously, counting the number of overvoltage actions through pulse detection; and performing a self-test on the device. The monitoring data and diagnostic results are wirelessly transmitted to the backend. The beneficial effect of this invention is that it can integrate the dynamic correction threshold for temperature and humidity, improving the accuracy of moisture diagnosis.

A method, apparatus, device, and readable storage medium for assessing the condition of a grounding grid are disclosed. The method includes: measuring the grounding impedance, contact voltage, and step voltage of the grounding grid through a test circuit; correcting the contact voltage and step voltage using a current correction factor; determining the optimal reference point from multiple candidate reference points of the grounding grid based on the on-resistance time series and upstream interference current spectrum of each candidate reference point, and measuring the on-resistance of the optimal reference point; calculating the scores of each of the grounding impedance, contact voltage, step voltage, and on-resistance based on their respective measured values, historical benchmark values, and safety limits, combined with their respective weights; summing the scores to obtain the total condition score of the grounding grid; and determining the safety level of the grounding grid based on the total condition score. This application enables a scientific and accurate assessment of the safety condition of the grounding grid, better ensuring the safe and stable operation of the power system.