6results about How to "Obvious fault features" patented technology

The invention relates to the technical field of data processing, and discloses a double-end fault positioning method based on signal enhancement, which is used for improving the efficiency of double-end fault positioning based on signal enhancement. The method comprises the following steps: acquiring and preprocessing electrical signals at two ends of a power transmission line to obtain preprocessed synchronous electrical signals; performing adaptive enhancement processing on the preprocessed synchronous electrical signal to obtain an enhanced fault feature signal; performing time-frequency analysis and feature extraction on the enhanced fault feature signal to obtain a fault feature vector and a key parameter; performing machine learning analysis on the fault feature vectors and the key parameters to obtain a fault type identification result and initial fault position estimation; performing multi-algorithm fusion analysis on the preliminary fault position estimation to obtain an accurate fault position coordinate; and performing geographic information mapping and field verification on the accurate fault position coordinates to obtain a fault positioning result and system optimization data.

The invention discloses a cable fault positioning method and system based on reflected wave decomposition and kurtosis sorting, and aims to solve the problem that a cable fault is difficult to detect under a low impedance change rate. The method comprises the steps of transmitting an incident excitation signal to a cable to obtain a first reflection signal in the cable; an improved VMD algorithm is adopted for decomposition to obtain K IMF components, and the IMF with the maximum kurtosis is selected as a second reflection signal; acquiring a time-frequency distribution curve of the second reflected signal by using short-time Fourier transform and frequency spectrum redistribution technologies; and constructing a two-dimensional energy-time curve by extracting an energy value and time under the frequency of the maximum energy amplitude point, and determining a fault position. The system is composed of an incident excitation module, a decomposition module, an STFT-RSP module and a fault positioning output module, and the positioning method is achieved. According to the method, the limitation of a traditional spread spectrum time domain reflection positioning method in cable fault detection is effectively overcome, and an efficient and accurate instructive technology is provided for cable fault positioning and detection.

The present invention provides a protection method for a new energy line with a high proportion of polarity differences of the first four voltage traveling waves. The method first derives the expression of the refraction-reflection coefficient of the wave impedance discontinuity point and obtains its value range. Then, according to the refraction-reflection process of the traveling wave when faults occur at different positions, the expression of the line mode voltage traveling wave at the protection installation is derived. The polarity characteristics of the first four voltage traveling waves when faults occur at different positions can be obtained by using the value range of the refraction-reflection coefficient, and it is concluded that the polarities of the first four voltage traveling waves are the same when there is a fault outside the zone, and the polarities of the first four voltage traveling waves are different when there is a fault inside the zone, and fault identification is performed based on this. The method uses the polarity characteristics of the traveling wave for fault identification. Compared with time characteristics and amplitude characteristics, polarity characteristics are easier to identify and have higher reliability, small calculation amount, and wide application range. At the same time, this scheme is a single-ended quantity protection, which has the advantages of no need for communication and fast action speed, and can reliably identify faults.

The invention relates to a fault diagnosis method, device and equipment and a computer readable storage medium. The method comprises the following steps: acquiring an arc cosine value and an arc sine value corresponding to each piece of power parameter information in a power parameter information set of power electronic equipment; determining a triangular difference characteristic value of each electric power parameter information according to the arc cosine value and the arc sine value corresponding to each electric power parameter information; according to each triangular difference characteristic value, constructing a power parameter characteristic graph of the power electronic equipment; and processing the power parameter characteristic pattern by using a parameter fault diagnosis model to obtain a fault diagnosis result of the power electronic equipment. By adopting the method, the accuracy of the fault diagnosis result of the power electronic equipment can be improved.

The application discloses a gear transmission system vibration signal immediate dense fault characteristic component decomposition system and method, comprising: a fault characteristic order library unit, an envelope signal generation unit, an arbitrary order harmonic decomposition unit and a monitoring index construction unit, wherein: the fault characteristic order library unit calculates the fault characteristic order of the measured vibration signal by using the existing gear dynamics and kinematics knowledge; the envelope signal generation unit carries out time-varying filtering on the signal components near the instantaneous meshing frequency on the time-frequency surface of the measured vibration signal, and calculates the modulation component of the instantaneous meshing frequency component; the arbitrary order harmonic decomposition unit determines the instantaneous frequency of each fault characteristic component according to the input shaft speed and the fault characteristic order, and obtains the time domain waveform of each fault characteristic component by using an optimization algorithm to jointly solve all positioned fault characteristic components; and the monitoring index construction unit constructs a targeted health index according to the time domain waveform of the fault characteristic component, which is used for state monitoring of the transmission system. Under the conditions of strong time-varying working conditions and strong noise, the application can accurately extract multiple signal components adjacent to each other on the time-frequency surface and generate a monitoring index used for state monitoring of the gear transmission system at a low calculation cost.

The invention provides a GMM (Gaussian Mixture Model)-based cable reflection coefficient spectrum noise reduction method and a related device. The method comprises the following steps: converting a reflection coefficient spectrum X of a detected power cable collected by a reflection coefficient spectrometer into a parameter model s (n); respectively extracting a real part and an imaginary part of the parameter model s (n), constructing a two-dimensional matrix xn, processing observation data based on the two-dimensional matrix xn by using a Gaussian probability density function, and solving a log-likelihood function for the Gaussian probability density function; updating parameters in the iterative log-likelihood function by adopting an EM algorithm until convergence; and eliminating interference data in the observation data, and outputting a noise reduction result. According to the method, the noise level in the cable reflection coefficient spectrum can be remarkably reduced, the signal-to-noise ratio of signals is improved, fault features are more prominent, and a more accurate data basis is provided for subsequent fault diagnosis.