Transformers | Is It Time To Upgrade?

Published 07 Mar 2022

Transformer Replacement Projects Were A Great Success For Smith Brothers In 2021

• Special thanks to Ben Whitaker Business Development & Sales Manager at Smith Brothers 
  for the kind permission to republish

Transformers

Alongside some of the large connections we talk about often, our services and infrastructure division are always working away in the background – to ensure our customers remain online 24-7-365.

And, as technology progresses, transformers have become more efficient in performing their duty of increasing or decreasing voltage for electrical distribution. With that in mind, our Business Development & Sales Manager, Ben Whitaker, takes a look at why replacing your transformer with a modern alternative could result in a ‘greener’ site whilst reducing energy bills.

Transformer replacement projects were a resounding success for Smith Brothers in 2021, and saw us complete 19 in total as organisations continued to strive to reduce carbon emissions and operate their sites more efficiently.

Yet, rather than simply ‘fixing a problem’, investment in new technology which can help to counter rising energy tariffs across the UK has been a firm topic of conversation for our team. It’s nothing new, though. In fact, a study in 2018 suggested that lost energy in transformers contribute to 25% of the UK’s wasted energy.

What’s more, the European Union estimates that 2.9% of all electricity generated across the continent gets wasted in lost energy in transformers, this combined figure equates to 93.4TWh – enough to power Denmark for three years.

Over the past 12 months, Smith Brothers has contributed to the energy sector in the UK significantly through the construction and delivery of renewable energy projects – but also by replacing aged and inefficient transformers.

Transformer Regulation No. 548/2014

During their operation, transformers will lose heat, but legislation imposes in the EU the maximum level of losses for transformers placed on the market or put into service after 1st July 2015. And, while most pre-2014 transformers are manufactured to an undetermined efficiency level, we refer to these as ‘standard loss transformers’.

As of 2014, the minimum requirement for installed transformer assets adhered to Tier 1 level of efficiency. Further regulations were imposed in June 2021, introducing Tier 2, which determines an improved efficiency for newly manufactured transformers.

Tier 2 transformers have been readily available via manufacturers for some time – and have been included in any Smith Brothers tender proposals as a matter of default since 2018. Further energy savings can be achieved through the provision of a Wilson e3 amorphous core transformers, which is also something which we’re proud to be able to supply and install.

No Load Losses

No Load Losses arise within the magnetic core of a transformer and happen as a result of the energy consumed in hysteresis and eddy currents within the material as it is taken through its alternating cycles of magnetisation, in the UK 50 times per second i.e. 50Hz.

There are two ways of reducing no load losses in a transformer:

1) Reduce flux density by increasing the cross-sectional area of the magnetic core. 2) By using higher grades of core steel to reduce the watts/kg for a particular flux density.

The ‘no load losses’ of a transformer is a constant loss of energy and does not vary with increase/ decrease of load.

Load Losses

Load losses arise primarily because of the resistance of the transformer windings, that is the losses produced by the flow of current within the windings. Increasing the copper or aluminium cross-sectional area within a transformer winding has the effect of reducing the current density of the winding – this has the effect of reducing the losses. The load loss of a transformer varies to the square of the load.

Generally speaking – the larger kVA rating and the higher % load of this kVA rating, the more savings can be made by minimalising load/ no load losses.

Detailed below, is a comparison of the no load losses and full load losses of a 1000kVA ‘Standard Loss’ transformer, manufactured in 2013, prior to Tier 1’s introduction and a modern, 1000kVA Tier 2 transformer. We have also included the data for a Wilson e3 amorphous core transformer for comparative purposes. The monetary savings shown are subject to the transformer being run at 80% load 24 hours a day, 365 days a year at an energy tariff average of 12p per KWH.

How do I work out how much energy is being lost from my transformers?

Due to fluctuating loads pulled from individual transformers on operational sites, it’s important to find the right partner to carry out load monitoring and power quality surveyance in order to accurately determine the specific lost energy of sites’ existing transformers.

A good supplier should consider these specific elements:

• 7-day detailed power and power quality logging at nominated LV incomers. Current, voltage, kW, kVA, power factor, harmonics (I& V), flicker, frequency, harmonic loss factor and unbalance
• Load analysis and dentification of voltage dependent equipment
• Determination of PFC requirement and specification
• Detailed analysis of all logging data including harmonic analysis against ENA G5/4-1 at each LV supply (400V)
• Determine true loading of transformers using harmonic derating
• Calculation of existing transformer losses and energy savings associated with selected replacement/s
• Compilation of the technical report including savings & outline recommendations, where applicable

Smith Brothers Ltd is a large, turnkey electrical contractor with over 20 years’ experience. Since their inception in 1999, they have worked on a vast portfolio of projects throughout the UK and overseas, both as an ICP and EPC contractor on schemes up to 132kV.

Offering a range of services and can cater for everything from the delivery of a turnkey project – including design, the supply and commissioning of equipment and cabling installations from LV up to 132,000 volts (220,000V in ROI).

With over 10 years’ experience in the power industry — Ben has specialised in many power distribution projects, as well as maintenance and HV/EHV connections throughout his career. He is responsible for new sales and quotation conversion.

For further information, or an initial discussion regarding replacement transformer options, contact business development and sales manager, Ben Whitaker on: 07387 108 377 or email [email protected].

Stockists | 11kV 33kV 66kV Joints Terminations Connectors – 3M Pfisterer Nexans

THORNE & DERRICK

Thorne & Derrick are national distributors of LV, MV & HV Cable Installation, Jointing, Substation & Electrical Equipment – servicing businesses involved in cabling, jointing, substation, earthing, overhead line and electrical construction at LV, 11kV, 33kV, 66kV and EHV. Supplying a complete range of power cable accessories to support the installation and maintenance of low/medium and high voltage power systems:

• Slip-on Cable Terminations
• Cold-shrink Cable Terminations
• Heat-shrink Cable Terminations
• Cable Joints – Heat & Cold-shrink
• Separable Connectors (Euromold)
• Surge Arresters & Switchgear/Transformer Bushings

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