Insulated device diagnosing system and partial discharge detecting method

Abstract

An insulated device diagnosing system capable of judging the deterioration, lifetime, defects and so on of a device highly sensitively and precisely. The intensity at each voltage phase angle is measured at a plurality of specific frequencies taking high voltage phase angles as the abscissas. The deterioration, lifetime and the kind and extent of abnormality of the device are judged from the pattern and intensity of the spectral distribution which is obtained by peak-holding the measured intensity for some time period. According to the present invention, partial discharge can be measured highly sensitively and precisely to diagnose the deterioration, lifetime and the extent of defect of the device. As a result, the insulation reliability of the device can be improved, and which part of the device should be repaired/replaced can be grasped before disassembly of the device, thereby cutting the maintenance cost.

What is claimed is:  
     
         1 . An insulated device diagnosing system comprising: an antenna provided in an insulated device; a pattern generator for receiving a partial discharge signal from said antenna and preparing detection data such that periods elements are given to a plurality of specific frequencies; a neuro computer or a finger printing method operation unit for operating the detection data prepared by said pattern generator; and judgment unit for diagnosing the extent of abnormality, the deterioration or the lifetime of said device from the operation result of said operation unit.  
     
     
         2 . An insulated device diagnosing system according to  claim 1 , wherein the distribution of the frequency components of the detection signal is also measured for specifying the specific frequencies to be detected.  
     
     
         3 . A partial discharge detecting method comprising the steps of: inputting a partial discharge signal from an input terminal; preparing detection data which are given periodic elements at a plurality of specific frequencies of partial discharge signal; and diagnosing the extent of abnormality, deterioration or lifetime of the device from the pattern or intensity of the prepared detection data.  
     
     
         4 . A partial discharge detecting method comprising the steps of: inputting a partial discharge signal from an input terminal; determining the intensity in which said partial discharge signal is expanded for each frequency by an FFT or a spectral analyzer to select a plurality of specific frequencies from the frequencies having high intensities, detecting the intensity of each frequency of said partial discharge signal to select a plurality of specific frequencies, of which the intensities exceed a predetermined value, or selecting the frequency having the highest intensity from the specific frequencies; preparing detection data which are given periodic elements at a specific frequency selected; and processing at least one of said detection data or displaying the same on a screen to detect the partial discharge.  
     
     
         5 . A partial discharge detecting method comprising the steps of: inputting a partial discharge signal from an input terminal; preparing detection data such that a plurality of specific frequencies of a partial discharge signal are given periodic elements; preparing sampling data by differentiating either averaged data averaged from detection data of different frequencies or known data from the individual detection data, or by differentiating the intensities of the detection data detected by antennae provided in different positions, between identical frequencies; and diagnosing the extent of abnormality, the deterioration or the lifetime of the device from the pattern or the intensities of the prepared sampling data.  
     
     
         6 . A partial discharge detecting method according to  claim 3  or  4 , wherein the extent or kind of abnormality, the deterioration or the lifetime of the device is diagnosed by processing said detection data by a neuro or a finger printing method  
     
     
         7 . An insulated device diagnosing system according to  claim 1  or  2 , wherein said insulated device is a gas insulated breaker, wherein said partial discharge signals coming from a plurality of antennae provided at different positions in said gas insulated device are measured synchronously, and wherein the partial discharge is located from the spectral patterns or intensity ratios between said detection data between the same frequencies.  
     
     
         8 . A partial discharge detecting method comprising the steps of: preparing detection data given periodic elements for one of a plurality of specific frequencies; and processing said detection data or displaying the same on a screen to detect partial discharge.