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Aspects of partial discharge measurement. 1 Introduction 2 Historical overview 3 Digital measuring techniques 4 Future trends 5 Summary. Aspects of partial discharge measurement. 1 Introduction. why it´s necessary to know more about partial discharges (pd)?.
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Aspects of partial discharge measurement 1 Introduction2 Historical overview 3 Digital measuring techniques 4 Future trends 5 Summary Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement 1 Introduction Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
why it´s necessary to know more about partial discharges (pd)? Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
For avoiding outages of electri-cal power supply the measure-ment of pd´s seems to be neces-sary Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
pd´s can be an indicator for „weak points“ into the electrical insulation ! • pd might be caused by • poor design of the insulation • failures during manufacturing or assembling • failures by electrical, thermal, mechanical, … overstress in operation • normal ageing or degradation processes Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
the pd- measurement as an important tool for quality control is used not only in the electrical power engineering, but more and more in other application fields of electrical insulation • low voltage power devices (motors, transformers, .. ) • electronic devices • … Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
typical quality defects in MV- GIS • - particle on the insulators • missing bolts or bad contacts • on conductor- connections • - free potential components • - microvoids into insulators • - . . . Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
typical quality defects in power cables protrusions on conductive sheets microvoids cracks(conductive, insulated) Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
typical quality defects in power cables water tree (wt) wt + electrical tree Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
typical quality defects in power cables oil- paper cable connectors Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
basic questions for pd measurement • how pd´s can be measured ? principles sensitivity • kind of failure („weak points“) ? • identification • dangerousness • where pd´s (weak points) are located ? localization Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement 1 Introduction2 Historical overview Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Historical overview [G.C.Lichtenberg, 1777)] Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Historical overview detection of failures on overhead lines and power transformers (B.Koske 1939) Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
measurement principles apparent charge q 1:Tp / T2 = 1 µs / 5 µs 2:Tp / T2 = 5 ns / 50 ns 3:Tp / T2 = 5 ns / 20 ns Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
first devices Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
narrowband measuring devices less disturbances easy handling no special experiences Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
broadband measuring devices more information about the pd- processes • more suszeptibly to noise, disturbances • special knowledge is requested Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
first devices Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
measurement principles [IEC 60270] Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
real pd spectra Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Standardized measuring circuit [IEC 270, 60270] Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
How dangerous are pd´s ? Is there any correlation between the measured charge and the lifetime ? Qkrit = ? moisture of paper w more informations about the pd- processes were necessary ! Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement [Izeki, Tatsuta, 1984] Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement typical PRPP Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement 1 Introduction2 Historical overview 3 Digital measuring techniques Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques model sensors 1 recognition diagnosis analysis, 2 action data acquisition cbm, service, risk assess-ment n database Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
statistical parameters of pd´s [see also Gulski, 1991] Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
digital measurement techniques statistical data of typical pd- sources stored in a database diagnostic (expert) system Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement typical pd- reference -data -base of available pd- systems ? measured pd - pattern product- specifical- pd- data must be obtained ! Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Aspects of partial discharge measurement high measuring sensitivity high susceptibility to noise, disturbances, … Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
Sources of electromagnetic disturbances 1 net connection 2, 11 power supply 3 hv- transformer 4 low pass filter 5 hv leads 6 coupling cap. 7 free potential obj. 8 stochastic disturb. 9 periodic disturb. 10 ground Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
suppression of disturbances radio/HF- suppression impuls- suppression amplifyer electronic integrator processing reflection- suppression [Lemke, 1981] Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
suppression of disturbances Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
suppression of disturbances screening of the testroom Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
suppression of disturbances noise signals, caused by SFC- generator, located in the same testroom new methods for suppression of disturbances are requested Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
localization of the pd- producing „weak points“ ? classical method (reflectrometry) • non electrical (classical) methods (acoustical, optical, …) ultra- high- frequency method (UHF) (electromagnetic field , combined with acoustic measurement) Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
(classical) principle of reflectrometry Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
1 2 3 Richtkoppler Richtkoppler A B C D methods of failure localization in cable- joints -1 Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
methods of failure localizationin cable- joints -2 Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik
methods of failure localization(classical acoustic method) Prof .Dr.-Ing.habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik