Partial discharge

About: Partial discharge is a research topic. Over the lifetime, 13997 publications have been published within this topic receiving 102058 citations. The topic is also known as: PD.

Partial Discharge Location in Power Transformers

Abstract: In a power transformer, high levels of partial discharge activity may lead to an insulation failure. If a partial discharge (PD) could be detected and located before the insulation fails, the transformer could be repaired or replaced before any consumers connected to the transformer lose supply. A technique is described in the paper that can be used to locate a PD in a power transformer with a continuous disc type winding. The technique requires knowledge about the physical geometry and design parameters of the transformer and also information about the characteristics of how the pulse or pulses caused by the PD propagate through the winding. The latter is difficult to obtain and consequently numerous simulation studies with slightly different assumptions were necessary before the technique could be considered validated. This involved analysing the data available at the terminals when a PD occurred in the winding and trying to extract the features related to the PD location. An algorithm using feature template matching has been used to locate the PD source in a 110 kV continuous disc type winding. Experimental tests carried out on this type of winding were extremely important in verifying the validity of the PD location algorithm. Results indicate that a location accuracy of better than 5% of the winding length is normally achieved.

Partial discharge recognition using neural networks: a review

Abstract: Partial discharge (PD) recognition using neural networks is studied. The paper offers a description of the main neural networks used, their recognition rate as well as comments on the variety of PD parameters fed to neural networks. Problems regarding the stochastic nature of PD, the multiple defects and the influence of the voltage level on the recognition rate are discussed. Proposals for future work are made.

Study of Partial Discharge Measurement in Power Equipment Using Acoustic Technique and Wavelet Transform

Abstract: This study proposes a noncontact type of acoustic measurement system and applies wavelet transform to noise suppression in order to raise the correct partial discharge (PD) signal identification rate. We first investigate an acoustic measurement method in the laboratory and apply the wavelet transform to suppress noise. A wavelet mother function most similar to the acoustic PD signals is chosen to set the filtering threshold value for the wavelet transform. Finally, the proposed acoustic measurement system is applied on line to epoxy-resin transformers, power distributors and the like. The superior measurement results we obtained will be able to help maintenance personnel eliminate field noise to correctly identify the PD fault types of power equipment.

Method and apparatus for the detection and location of faults and partial discharges in shielded cables

Abstract: A method and apparatus for locating an incipient fault at a point along the length of an insulated power line includes the application of an excitation voltage at an open end of the power line, and the signal pulse transmitted along the power line to the open end is passed through a high pass filter to remove the portion of the signal which is at a frequency below the excitation voltage and its harmonics. The filtered signal is amplified and passed through a band pass filter to remove a high frequency portion of the signal containing a large proportion of noise relative to the frequency of the partial discharge frequency from the incipient fault. This filtered signal is passed to a digital storage device adapted to be triggered by a signal of a predetermined amplitude, and the triggered digital storage device receives the amplified signal directly from the amplifier and stores digital data concerning amplitude and time for the peaks of the amplified signal for a predetermined period of time. The stored digital data is processed to identify the peaks reflecting the point of partial discharge in the power line.

Power cable partial discharge signal denoising method based on wavelet analysis

Abstract: The invention provides a partial discharge signal denoising method based on wavelet analysis, which belongs the technical field of signal processing, and is mainly applied to power cable partial discharge signal denoising. The method for performing intelligent denoising processing on power cable partial discharge signals specifically includes: selecting optimal wavelet basis by using minimum description length (MDL) standard of the information theory, selecting a denoising method, performing wavelet decomposition according to a certain decomposition level, processing wavelet coefficients according to different threshold functions, performing wavelet reconstruction according to the processed wavelet coefficients, and achieving the denoising. The partial discharge signal denoising method solves the problem of manual screening of conventional partial discharge signal denoising, thereby achieving the purpose of the intelligent denoising of the partial discharge signals.