Why test

REASON 1

• 40% PROBLEMS IN TRANSFORMERS OLTC

REASON 2

• HQ study showed 12% require maintenance before manufacturer’s suggested period.

• Presentation on OLTC diagnostics, Laurent Allard, ABB Secheron, Euro TechCon Chester UK 2010

REASON 3

• About one in 20 OLTC failures lead to transformer main tank failure

• [western electricity coordinating council]

• WECC Substation WG meeting minutes, Vancouver Washington, May 2006

REASON 4

• About 33% of OLTC failures are caused by incorrect maintenance and bad reassembly.

• P.Kang, D. Birthwistle, et al. "Non invasive on line condition monitoring of OLTC", IEEE proceedings January 2000, Generation, transmission and distribution, Volume 3, pp.2223-2228

History of DRM• First proposal 1994

• First results published 1999-2000

Our experience (10 years)

• Hall probes and scope

• Modern electronic instruments + lap-top

Today

• Working group formed in Dublin 2010

Working Group – Madrid 2011

Workshop – field testing

WG meeting Stockholm 2012

WG Participants

• ESBI Ireland • Liandon The Netherlands • ARCE Spain • Gas Natural Spain • EAC Cyprus • Terna Italy • ELIA Belgium • MHY Pro Power Malaysia • Elektroprenos Bosnia • EDF France• Siemens Germany

• ONE Nordic Sweden • DV Power Sweden • MR - Reinhousen • Doble PowerTest UK • Omicron Austria • Seitz Instruments

Switzerland • PG&E USA • ABB• Stevo Electric• Megger

Technology

• In 1999 old technology with scope

• In 2004 computer recording– RS232 communication

• In 2009 high speed recording– USB communication

• In 2011 demagnetization

• In 2012 three phase recording

Hall effect probe and scope

Old instrument

New instrument

References• DYNAMIC RESISTANCE MEASUREMENTS IN LOAD TAP CHANGER - Luis Miguel Perea. Angel Ramos

Gómez Unión Fenosa Distribución, Spain, José Luis Lozano Gómez  Norcontrol Soluziona, Spain • A DIAGNOSTIC TO DETERMINE THE CONDITION OF THE CONTACTS OF LOAD TAP CHANGERS IN A

POWER TRANSFORMER H.F.A. Verhaart and Andre E. Lux, KEMA T &D Consulting, 2004 at Doble conf.• Advanced on-site diagnosis of transformer on-load tap changer, Jur J. Erbrink1, Edward Gulski1, Paul P.

Seitz2, Rory Leich3; 1Delft University of Technology, The Netherlands; 2Seitz Instruments AG, Switzerland; 3Nuon Tecno, The Netherlands, IEEE INTERNATIONAL SYMPOSIUM ON ELECTRICAL INSULATION 8 - 11 June 2008 Vancouver, BC, Canada

• EXPERIMENTAL MODEL FOR DIAGNOSING ON-LOAD TAP CHANGER CONTACT AGING WITH DYNAMIC RESISTANCE MEASUREMENTS, Jur J. Erbrink2, Edward Gulski1, Johan Smit1, Rory Leich3; 1Delft University of Technology, The Netherlands; 2Seitz Instruments AG, Switzerland; 3Liandon, The Netherlands, Cired 2009 paper 0134

• On Load Tap Changer Dynamic Resistance Measurement, By Raka Levi, Alex Cincar, Keith Bensley, published in Australia at TechCon 2010

• Experience on Dynamic Contact Resistance Test on Eroded and Worn-Out Tap-Changer Contacts, R. Samsudin, Yogendra, TNB Research Sdn Bhd; A.Berhanuddin, Y.Zaidey, Tenaga Nasional Berhad; M.Haneef, MHY Pro-Power Services Sdn Bhd - published 2010 in Malaysia

• Interpretation of Dynamic Resistance Results of On-Load Tap Changers; J.J. Erbrink1, E. Gulski1, J.J. Smit1, R. Leich2, P.P. Seitz3 and B. Quak3 1 Delft University of Technology, Delft, the Netherlands 2 Liandon, Alkmaar, the Netherlands 3 Seitz Instruments AG, Niederrohrdorf, Switzerland  published Japan 2010

• Reproducibility of Dynamic Resistance Measurement Results of On-Load Tap Changers – Effect of Test Parameters; J.J. Erbrink1*, E. Gulski1, J.J. Smit1, R. Leich2, P.P. Seitz3 and B. Quak3 1 Delft University of Technology, Delft, the Netherlands 2 Liandon, Alkmaar, the Netherlands 3 Seitz Instruments AG, Niederrohrdorf, Switzerland - Japan 2010

• Condition Assessment of OLTC using static and dynamic resistance tests; Brendan Diggin, ESBI, presented at the AMforum FORUM Dublin 2010

• Doctoral thesis:  OLTC Diagnosis on High Voltage Power Transformers using Dynamic Resistance Measurements, Jur Erbrink, Technische Universiteit Delft, 28. March 2011

The end

http://amforum.org/site/drm.htm