In this edition we go through some basics of bushing monitoring, and how our IntellixTM BMT 300 and PerceptionTM software are used. We also highlight the railway transportation market as a possible additional outlet for our products in the industrial sector.I also want to thank all of you who participated in the 2015 Annual ITP Survey. We received 37 responses, up from last year, and we are analysing the results. More to follow in a future newsletter.

Message from Dominique

Get access to the ITP siteWe regularly release new product information and updates on the Transformer M&D - ITP Product Information Site. The site helps you build your knowledge of M&Ds products and find answers to your questions. To get access to the site please contact Philip Cassidy at philip.cassidy@ge.com

ITP NewsletterMay 2015

On-Line Bushing Monitoringusing the Intellix BMT 300

By Alfonso Ambrosone

High voltage condenser bushings of power transformers are amonst the most vulnerable of all operating equipment used. They are subjected to very high dielectric, mechanical and thermal stresses, thus making bushing failure a leading cause of transformer failures.

High voltage bushings are generally oil-filled condenser type OIP (Oil Impregnated Paper) bushings which have a central conductor wound with alternating layers of paper insulation wrapped in tin foil (creating capacitive layers designed to provide uniform voltage drops between each layer). These are then housed in a protective weather casing (usually porcelain) and filled with insulating oil.

Off-Line measurements of bushing capacitance C1 and power factor PF (or tan delta) have for years been carried out to determine the operational condition of the bushings. However, off-line testing of bushings requires a transformer outage and is therefore only done at long periodic intervals (2 to 5 years), long enough time for a quickly developing fault to be missed, causing a catastrophic transformer failure. Because off-line tests are also performed at much lower voltages and under very different temperature conditions (due to absence of load), some weaknesses may not show up under these less than operating conditions, thus reducing their reliability. Today, high speed microprocessor technology makes it possible to carry out real-time bushing measurements with the transformer remaining on-line. Continues on page 2..

We now have two brochures comparing all our Single Gas and our Multi Gas DGA products, to make it easier for you to visualise the differences and present them to customers.

The Multi Gas brochure highlights which gases are measured by which product, what these gases represent and what standard diagnostic methods they enable.We already had a Single gas product comparison comparing all the features and options and this has been updated.

Both these brochures can be found on the ITP site under the Common documents sections of the Monitoring and Monitoring & Diagnostics areas.

Product Comparisons

We remind you that high definition images of all our products are available for you to download. They appear under each product in the Images folder. They are useful if you want to upgrade your own web site or need them for marketing projects.

Product Images

May 20, 2015 - New TRANSPORT XTM Brochure May 07, 2015 - Updated all Kelman product brochures Apr 29, 2015 - New Product Comparison Brochures Apr 29, 2015 - Updated Kelman MINITRANSTM manuals Apr 28, 2015 - TB re Perception with non-english Windows Apr 28, 2015 - Modbus registers for Kelman products Apr 27, 2015 - Guide spec for 3, 5, 9 gas + moisture Apr 23, 2015 - MINITRANS Direct Mount Instructions Apr 17, 2015 - Updated TRANSFIX DGA 500 Brochure (updates available on ITP site)

Latest Updates:

Dominique.Legrand@ge.comM&D Marketing Manager

GE Grid Solutions (UK) Ltd, Lissue Industrial Estate East, Unit 1, 7 Lissue Walk, Lisburn BT28 2LU, United Kingdom

Tel: +44 (0) 2892 622915 / gedigitalenergy@ge.com

GE, the GE monogram, Kelman, Hydran, Intellix, TRANSFIX, MINITRANS, MULTITRANS and Perception are trademarks of the General Electric Company. Copyright 2015, General Electric Company. All Rights Reserved.

Some of you may be aware that Richard Ormsby our Finance Leader has taken up a new position within GE Power Delivery. Marie-Clare Fidgeon will now

be the acting Finance Leader. Marie-Clare has been with the company almost 10 years and came through GEs FMP and Corporate Audit Staff leadership programmes. She has spent the last 5 years in Lisburn with the M&D business as the Finance Manager for the Technology, Services and Manufacturing teams.

Marie-Clare Fidgeon Acting M&D Finance Leader

Its not all about generation and transmission transformersDid you know that in China we have supplied TRANSFIX products for several railway projects. As of 2014, the country had 112,000 km (69,594 mi) of railways, the third longest network in the world, including 16,000 kilometres (9,942 miles) of high-speed rail (HSR). Around 54% is electrified. There are 16 bureaux and 5 companies under China Railway.

The key customer issues with rail are: (1) they want reliability for newer major lines which leads to monitoring of key transformers; (2) on older lines, transformers were installed at the same time and therefore will need to be replaced at the same time, which is not palatable. Any way to identify transformers whose replacement can be delayed helps them resolve this problem.

For each rail substation, there are normally at least two traction transformers.

Did you know we have sold?16 Kelman TRANSFIX Zhengzhou Railways Bureau15 HydranTM 201Ti Guangzhou Subway2 Kelman MULTITRANSTM Zhengzhou Railways Bureau2 Kelman MULTITRANS Heng-Cha-Ji Railway Project

By Richard LukeOn-Line Bushing Monitor using the Intellix BMT 300 continued...

GEs Intellix BMT 300 is an on-line system that continuously provides information regarding the health and condition of the transformer bushings by monitoring the capacitance change and the relative power factor change (tan delta) of up to six bushing. It uses sensors connected to each bushings tapping point.

The BMT 300 encompasses the additional functionality of detecting the presence of Partial Discharge (PD) activity inside the insulation of the transformers main tank. PD is a low-energy spark which partially destroys a small internal portion of the insulation. It will self-feed and increase exponentially and eventually, through gradual erosion, cause a breakdown in the solid or fluid insulation and lead to transformer failure. The BMT 300 can detect PD activity within the transformer using the same connectivity and bushing sensors.

Polar charts are used in GEs Perception software as a diagnostic tool to identify and quantify, for each set of 3 bushings, the bushing in which the capacitance or power factor is changing more than the other two. External factors such as temperature and load variations which affect all three bushings similarly have their effect negated when data is plotted on the polar charts, thus reducing the risk of false alarms linked to a common cause factor. Polar charts are also used to discriminate against corona discharge that affects all phases when detecting PD.

The Intellix BMT 300 can monitor transformer bushings on a 3-phase transformer or a bank of three single phase transformers. It can monitor up to a total of six transformer bushings, typically three HV and three LV bushings. The transformer bushings must be of the condenser type and must have an available test tap so that the bushing sensor can be mounted to take the appropriate bushing measurements.

M&D and Railways In China

The attached picture is from a Kelman MULTITRANS used in the Heng-Cha-Ji railway project, which was installed in July 2014.