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Standards and Guides for Transformer Maintenance and Diagnostics

Matz Ohlen, Megger Sweden

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Testing and Standards

� CIGRE

• CIGRE Brochure 342 (SFRA-FRAX)

• CIGRE Brochure 414 (DFR-IDAX)

• CIGRE Brochure 445 (Guide for Transformer Maintenance)

� IEC, TC 14

• IEC 60076-1, Power Transformers

• IEC 60076-2, Temperature rise

• IEC 60076-3, Insulation levels, dielectric tests and external clearances in air

• IEC 60076-18, Measurement of frequency response (SFRA)

� ANSI, IEEE Transformer Committee

• IEEE C57.152 (former IEEE 62-1995)

• IEEE C57.12.00-2006 (under revision)

• IEEE C57.12.90-2006 (under revision)

• IEEE PC57.149 (SFRA)

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Guides and standards for transformer testing (1)

� Most standards (IEC and ANSI/IEEE) are focusing on new

transformers and factory testing

� Workgroups in e.g. Cigré have over the years produced a lot of

Technical Brochures (TB) e.g. on sweep frequency response

measurements (TB342), partial discharge (TB366), dielectric

response measurements (TB414) etc

� IEEE 62-1995 “Diagnostic Field Testing of Fluid-Filled Power

Transformers, Regulators, and Reactors” is probably the most

well-known guide for diagnostic field testing of oil filled power

transformers. The guide today belong to the IEEE C57-series and

last published revision is C57.152-2013

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Cigré Technical Brochure 445, 2011

Guide for Transformer Maintenance

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CIGRE TB 445

� Cigré TB 445, ”Guide for Transformer Maintenance”, was

published 2011

� TB 445 is a comprehensive combination of education handbook,

transformer encyclopedia and a guide for transformer

maintenance including guidelines for how to perform

measurements in the field

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TB 445- Content

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IEEE C57.152-2013

Guide for Diagnostic Field Testing of Fluid-Filled Power Transformers, Regulators, and Reactors

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IEEE C57-152

� IEEE C57.152 “Guide for Diagnostic Field Testing of Fluid-Filled

Power Transformers, Regulators, and Reactors”, is a revision of

IEEE 62-1995 and was published 2013

� IEEE C57.152 is a guide that “describes diagnostic field tests and

measurements that are performed on fluid-filled power

transformers and regulators” and does NOT contain general

information on transformer components and transformer

maintenance

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IEEE C57-152- Content

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”Diagnostic” and ”Maintenance” test charts” IEEE C57.152

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”Diagnostic” matrix CIGRE TB445

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Differences GIGRE - IEEE

� CIGRE test categories – by methodso Basic Electrical

o Advanced Electrical

o Dissolved Gas Analysis (DGA)

� IEEE test categorieso By component

o ”Event based”

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Diagnostic Technique (CIGRE)

� Basic Electrical

� Advanced Electrical

� Dissolved Gas Analysis (DGA)

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Basic Electrical

� Winding Ratio

� Winding Resistance

� Magnetization (excitation) current

� Capacitance and DF/PF

� Insulation Resistance

� Core Ground Test

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Winding Ratio

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Winding Resistance

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Magnetization (excitation) current

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Capacitance and DF/PF

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Capacitance and DF/PF - Bushings

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Leakage Reactance

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Insulation Resistance

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Core Grounding

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Advanced Electrical

� Frequency Response of Stray Losses (FRSL)

� Frequency Response Analysis

� Polarization/Depolarization

� Frequency Domain Spectroscopy

� Recovery Voltage Method

� Electrical Detection of PD

� Acoustical Detection of PD

� UHF Detection of PD

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Frequency Response Analysis

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Frequency Domain Spectroscopy(FDS/DFR)

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Bushingmeasurements

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Summary CIGRE TB 445

� TB 445 is a combination of a transformer handbook,

transformer encyclopedia and application guide for

transformer maintenance including guidelines for

transformer field testing

� Lots of very good information. Details and guidelines

can and will be discussed e.g. assessment data and

advantages/disadvantages with different

measurement methods (e.g. combined PDC-FDS

combination versus true AC DFR/FDS measurements)

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