D1 UK 2022

Dr Thomas Andritsch - D1 UK Regular Member

22nd November 2022

Introduction

• Associate Professor, University of Southampton
• Role includes Education (UG and MSc), Research (Industry and research council funded R&D on materials for HV systems, PhD supervision), Enterprise (HV consultancy) and Management (Tony Davies HV Laboratory)
• Previously roles at TU Delft (NL),TU Graz (AT), and Prince Songkhla University (TH)
• Cigre activities include UK member of D1.73, B1/D1.75 and previously D1.40
• Also active in IEEE (Senior Member, DEIS Administrative Committee, TC on Transport Electrification, Smart Grids, Nanodielectrics)

Dr Thomas Andritsch - D1 UK Regular Member

T.Andritsch@soton.ac.uk

SC D1 Materials and Emerging Test Techniques

CIGRE UK AGM, 22nd November 2022

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Study Committee D1 Scope

The scope of SC D1 is concerned with the monitoring and evaluation of:  

• New and existing materials for electrotechnology,
• Diagnostic techniques and related knowledge rules,
• Emerging test techniques which may be expected to have a significant impact on power systems in the medium to long term.
• Support of other study committees in their analysis of recently introduced and developing materials, emerging test techniques and diagnosis techniques

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Study Committee D1 - Organisation

New 2022:

SC Chair: Simon Sutton, UK

Secretary: Gordon Wilson, UK

Strategic Advisory Groups:

AG D1.01 Liquids and Liquid Impregnated Insulation Systems (Qiang Liu, UK)

AG D1.02 High Voltage and Current Testing and Diagnostic (Uwe Riechert, CH)

AG D1.03 Solid Materials (Jerome Castellon. FR)

AG D1.04 Gases (Karsten Juhre, DE)

Tutorial AG (Ivanka Atanasova-Hoehlein, DE)

Strategic and Customer AG (Simon Sutton, UK)

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Study Committee D1 Active Working Groups

CIGRE UK AGM, 22nd November 2022

Study Committee D1 – Active Working Groups

Study Committee D1 – Active Working Groups

Study Committee D1 – Active Joint Working Groups

Study Committee D1 – New Working Groups

Study Committee D1 New Technical Brochures

CIGRE UK AGM, 22nd November 2022

Study Committee D1 – New Technical Brochures

In the past 12 months the following technical brochures have been published:

• TB861 Improvements to PD measurements for factory and site acceptance tests of power transformers

Link to TB861 (e-cigre)

• TB856 Dielectric performance of insulating liquids for transformers

Link to TB856 (e-cigre)

• TB849 Electric performance of new non- SF6 gases and gas mixtures for gas-insulated systems

Link to TB849 (e-cigre)

TB 861

• UHF PD detection and IEC60270 tests respond to PD by very different mechanisms. Some PD may be detected predominantly by one method. Hence significant UHF signals from PD should be considered even if the IEC60270 test is passed during FAT. Furthermore, the UHF method can be applied as a repeat test during SAT, which is not normally possible for the IEC60270 PD test.
• TB sets out methods for ensuring comparability of PD readings between different UHF detection systems by characterising the sensitivity of the PD sensor and the transfer function of the subsequent measurement system. This is analogous to the manner in which different IEC60270 PD measurement systems are calibrated with reference to a defined stimulus at the input terminals. This does not mean calibrating UHF signals in terms of pC!

Convener: Sebastian Coenen (DE)

UK Contributors: Martin Judd

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TB 861

• Brochure sets out in detail a general UHF calibration procedure with several steps that should be performed
• Brochure contains guidelines regarding:
• Usable types of UHF sensors and their general advantages/disadvantages
• Number and location for UHF sensors at transformer tanks
• Frequency range used for UHF PD measurements
• Calibration of the system and necessary documentation
• Improving signal to noise ratio through knowledge of common noise sources
• Performance check procedure of the UHF setup

Improvements to PD measurements for factory and site acceptance tests of power transformers

TB856

• A tutorial was delivered during ICDL2022, at Seville, Spain on 29^th May 2022.
• Main brochure contents:
• Pre-breakdown and breakdown phenomena in transformer liquids
• Review of IEC liquid breakdown test methods
• Transformer insulation design
• Suggestions for future work
• Further research needed to better understand streamers; until then reliance on testing

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Convener: Lars Lundgaard

UK Contributors: Qiang Liu, Attila Gyore, Zhongdong Wang

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TB856

How streamers start and develop will depend on the background field geometry. Two main situations may exist:

• “Initiation-controlled breakdown”. This corresponds to the situation where a streamer, once initiated, will systematically propagate to breakdown. Typically, under uniform fields and being very sensitive to contamination.
• “Propagation-controlled breakdown”. This corresponds to the situation where a streamer, once initiated, will not necessarily propagate to breakdown. Typically, under divergent fields (point-toplane). Breakdown will depend on streamer velocity, gap and duration of the stress.

Dielectric performance of insulating liquids for transformers

TB849

• Follow-up of WG D1.51
• Brochure contents:
• State-of-the-art literature summary
• Set of tests suited to determine practical insulation strength of alternative gases
• Two round-robin tests:
• Electrical test campaign
• Gas analysis campaign

Convener: Christian Franck (CH)

UK Contributors: Manu Haddad, Tony Chen, P. Widger

TB849

RRT electrical test campaign

• 232 test series performed in 14 (fourteen) different laboratories
• Every test series completed by at least 2 different labs
• Novel gases, as well as SF6 reference measurements
• While some tests were in good agreement (e.g. SF6), it was not trivial to get consistent results for some gas mixtures
• All measurement data available open access for further evaluation (must be clearly referenced to this TB)

Electric performance of new non- SF6 gases and gas mixtures for gas-insulated systems

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TB849

RRT gas analysis campaign

• Single-source gas samples of C4-FN and C5-FK mixtures prepared and shipped to 7 labs around the world
• Assessment of accuracy with which gas can be analysed
• Different methods used by different laboratories to produce calibration gases and analyse gas composition
• Gas chromatography (GC) with Mass-spectrometry (GC-MS) and/or thermal conductivity (GC-TC), FTIR or UV analysis
• Accurate results with an uncertainty of ±0.2% abs. not trivial or consistently achievable

Electric performance of new non- SF6 gases and gas mixtures for gas-insulated systems

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Thank you for your attention!

Please get in touch if you have any questions!

T.Andritsch@soton.ac.uk

CIGRE UK AGM, 22nd November 2022