Aspects of partial discharge measurement 1 Introduction 2

Aspects of partial discharge measurement 1 Introduction Prof. Dr. -Ing. habil. Rainer Haller Electrical

why it´s necessary to know more about partial discharges (pd)? Prof. Dr. -Ing. habil.

For avoiding outages of electri-cal power supply the measure-ment of pd´s seems to be

pd´s can be an indicator for „weak points“ into the electrical insulation ! pd

the pd- measurement as an important tool for quality control is used not only

typical quality defects in MV- GIS - particle on the insulators -missing bolts or

typical quality defects in power cables protrusions on conductive sheets microvoids cracks (conductive, insulated)

typical quality defects in power cables water tree (wt) wt + electrical tree Prof.

typical quality defects in power cables oil- paper cable connectors Prof. Dr. -Ing. habil.

basic questions for pd measurement Ø how pd´s can be measured ? principles sensitivity

Aspects of partial discharge measurement 1 Introduction 2 Historical overview Prof. Dr. -Ing. habil.

Historical overview [G. C. Lichtenberg, 1777)] Prof. Dr. -Ing. habil. Rainer Haller Electrical Power

Historical overview detection of failures on overhead lines and power transformers (B. Koske 1939)

measurement principles 1: Tp / T 2 = 1 µs / 5 µs 2:

first devices Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University

narrowband measuring devices less disturbances easy handling no special experiences Prof. Dr. -Ing. habil.

broadband measuring devices more information about the pd- processes § more suszeptibly to noise,

measurement principles [IEC 60270] Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental

real pd spectra Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering

Standardized measuring circuit [IEC 270, 60270] Prof. Dr. -Ing. habil. Rainer Haller Electrical Power

How dangerous are pd´s ? Is there any correlation between the measured charge and

Aspects of partial discharge measurement [Izeki, Tatsuta, 1984] Prof. Dr. -Ing. habil. Rainer Haller

Aspects of partial discharge measurement Prof. Dr. -Ing. habil. Rainer Haller Electrical Power &

Aspects of partial discharge measurement typical PRPP Prof. Dr. -Ing. habil. Rainer Haller Electrical

digital measurement techniques Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering

digital measurement techniques model 1 sensors analysis, recognition 2 data acquisition n action diagnosis

statistical parameters of pd´s [see also Gulski, 1991] Prof. Dr. -Ing. habil. Rainer Haller

digital measurement techniques statistical data of typical pdsources stored in a database diagnostic (expert)

Aspects of partial discharge measurement typical pd- reference -data -base of available pd- systems

Aspects of partial discharge measurement high measuring sensitivity high susceptibility to noise, disturbances, …

Sources of electromagnetic disturbances 1 net connection 2, 11 power supply 3 hv- transformer

suppression of disturbances radio/HF- suppression amplifyer impuls- suppression electronic integrator processing reflection- suppression [Lemke,

suppression of disturbances Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering

suppression of disturbances screening of the testroom Prof. Dr. -Ing. habil. Rainer Haller Electrical

suppression of disturbances noise signals, caused by SFCgenerator, located in the same testroom new

localization of the pd- producing „weak points“ ? classical method (reflectrometry) à non electrical

(classical) principle of reflectrometry Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental

methods of failure localization in cable- joints -1 1 2 Richtkoppler A B Richtkoppler

methods of failure localization in cable- joints -2 Prof. Dr. -Ing. habil. Rainer Haller

methods of failure localization (classical acoustic method) Prof. Dr. -Ing. habil. Rainer Haller Electrical

future trends measuring sensitivity vs noise, disturbances (digital procedures, neuronal networks) interpretation of pd-

spectral analyzing of pd Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental

spectral analyzing of pd pd source zero span Prof. Dr. -Ing. habil. Rainer Haller

digital de- noising Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering

digital de- noising [Kranz, 1996] Prof. Dr. -Ing. habil. Rainer Haller Electrical Power &

identification of pd sources Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental

multichannel pd measurement Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering

dangerousness of pd Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering

dangerousness of pd for better understanding the physical processes of damaging or deterioration of

new parameters of pd- processes Prof. Dr. -Ing. habil. Rainer Haller Electrical Power &

new methods of failure localization Prof. Dr. -Ing. habil. Rainer Haller Electrical Power &

new methods of failure localization (combined UHF - acoustic method) acoustic measurement will be

summary Ø pd measurements are up to now an essential tool for quality testing

summary Ø basic investigations of insulation materials for finding a correlation between pd- parameters

Thank you Questions ? & Answers ! Prof. Dr. -Ing. habil. Rainer Haller Electrical

Slides: 75

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Aspects of partial discharge measurement 1 Introduction 2 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 Ø poor design of the insulation Ø failures during manufacturing or assembling Ø failures by electrical, thermal, mechanical, … overstress in operation Ø 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 à low voltage power devices (motors, transformers, . . ) à electronic devices à … 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 Ø how pd´s can be measured ? principles sensitivity Ø kind of failure („weak points“) ? identification dangerousness Ø 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 Introduction 2 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 1: Tp / T 2 = 1 µs / 5 µs 2: Tp / T 2 = 5 ns / 50 ns 3: Tp / T 2 = 5 ns / 20 ns apparent charge q 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 pdprocesses § 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 pdprocesses 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 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 Introduction 2 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 model 1 sensors analysis, recognition 2 data acquisition n action diagnosis cbm, service, database Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik risk assessment

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 pdsources 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 amplifyer impuls- suppression 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 SFCgenerator, located in the same testroom new methods for suppression of disturbances are requested Electrical Power & Environmental Engineering Prof. Dr. -Ing. habil. Rainer Haller University of West Bohemia Pilsen/ Czech Republik

localization of the pd- producing „weak points“ ? classical method (reflectrometry) à 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

methods of failure localization in cable- joints -1 1 2 Richtkoppler A B Richtkoppler C D Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik 3

methods of failure localization in 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

Aspects of partial discharge measurement 1 Introduction 2 Historical overview 3 Digital measuring techniques 4 Future trends Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

future trends measuring sensitivity vs noise, disturbances (digital procedures, neuronal networks) interpretation of pd- parameter (identifying, correlation to the lifetime) localization of defects on site testing Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

spectral analyzing of pd Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

spectral analyzing of pd pd source zero span Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

digital de- noising Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

digital de- noising [Kranz, 1996] Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

identification of pd sources Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

multichannel pd measurement Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

dangerousness of pd Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

dangerousness of pd for better understanding the physical processes of damaging or deterioration of insulation more/ other informations about the pdprocesses seem to be necessary - Δupd - Δwpd -… Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

new parameters of pdprocesses Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

new methods of failure localization Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

new methods of failure localization (combined UHF - acoustic method) acoustic measurement will be triggered by UHF- signal [Markalous, 2006] Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

summary Ø pd measurements are up to now an essential tool for quality testing of electrical insulation and diagnostic purposes Ø progress in digital techniques makes it possible getting more informations about pd`s at increased sensitivity Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

summary Ø basic investigations of insulation materials for finding a correlation between pd- parameters and lifetime Ø increasing measuring sensitivity for diagnostic measurements even under on- site conditions (new methods of filtering, neuronal networks, . . ) Ø using combined techniques for improved localization Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik

Thank you Questions ? & Answers ! Prof. Dr. -Ing. habil. Rainer Haller Electrical Power & Environmental Engineering University of West Bohemia Pilsen/ Czech Republik