Transformer energy performance standards being introduced all around the world are spurring transformer manufacturers, as well as their electrical steel, cable and coil winding equipment suppliers, to rethink materials, designs and manufacturing methods in a bid to balance performance with cost.

In 2010 the USA became the first market in the world to introduce energy performance legislation for medium voltage distribution transformers. Since then Japan has set a standard for industrial transformers, while standards bodies in China and India are making strong recommendations to utilities. In the meantime, the US Department of Energy (DoE) issued an amendment in January 2016 requiring even higher energy performance from distribution transformers up to 2500 kVA.

The EU became the next market to regulate all power transformers in July 2015 and discussions have already begun on an amendment due for 2021. Whereas the US DoE has focused on the total efficiency of a transformer under certain conditions, CENELECs (the European Committee for Electrotechnical Standardization) Minimum Energy Performance Standard (MEPS), has specified maximum losses for both the core and the winding for distribution transformers and minimum peak efficiency for power transformers.

"No one approach is better than the other - both have their benefits - but the EU metrics certainly offer a lot less flexibility to manufacturers in what materials they use and how they make the transformer," says Mahesh Sampat, president at EMS Consulting, a firm specializing in business and technical consulting in the field of transmission and distribution products. "The result is greater consistency of transformer design and performance across the network regardless of manufacturer."

Benefits for all
Kai Pollari, energy efficiency manager for ABBs transformers business unit says: "Despite the inherent pressure placed on manufacturers by standardization, some transformer buyers believe that manufacturers are the only beneficiaries with a view to driving up the initial capital cost of transformers. In actual fact, we all benefit. Global sustainability is a major driver, especially considering that 3% of all electrical energy generated globally is wasted due to transformer inefficiency. Reduced energy consumption due to the improved efficiency brings financial benefits throughout the lifetime of a transformer cumulatively exceeding the upfront marginal cost. Utilities are also able to guarantee greater reliability for their customers."

Professor Angelo Baggini, chairman of the CENELEC TC14 technical committee for power transformers says: "When drafting MEPS requirements we involve all stakeholders in the discussion, including manufacturers and utilities, so that we get the balance between cost, practicality and environmental benefits just right. In Tier 1 you can already see some concessions for practical reasons. For example, the support structures for pole-mounted transformers in some countries are not currently strong enough to support the increased weight of the latest generation of MEPS-compliant transformers and more time is needed to adapt - but our ambition is not unfeasible for the great majority."

Tough competition
Despite optimism in Europe, the introduction of transformer energy performance standards has not proved smooth sailing in the US for domestic electrical steel producers. Following the MEPS, European electrical steel producers may also lose out to foreign companies if they do not invest quickly enough.

"As the US regulation is based on minimum efficiency at 50% load, it places a great emphasis on reducing core loss, making higher grades of electrical steel the material of choice. The US domestic steel companies have limited capacity to produce such grades of steel but these materials are available to import from the rest of the world into Mexico and Canada. The domestic steel producers tried to protect their market but transformer manufacturers took their core manufacturing operations to Canada and Mexico and began importing finished core duty-free into the US under NAFTA (the North American Free Trade Agreement)," Sampat says.

"European steel producers are able to supply the higher grades but they havent scaled up yet in the way that Japanese and Korean companies have," Pollari adds. "One of the discussions between transformer manufacturers and steel producers is the need for steel producers to invest in upgrading their facilities to produce better steel in larger quantities, otherwise transformer manufacturers may be forced to import their materials from other countries. In the meantime, Japanese and Korean producers are continuing to build their knowledge and experience with higher grades of steel. The discussions are not as severe as in the US but they are still occurring."

Exciting opportunities
The tier 2 MEPS will require grades of steel that are not even being made yet, as well as changes to the design, windings and manufacturing methods.

"Reducing the core loss is a low-hanging fruit for transformer manufacturers. They can make the product in much the same way just with higher grades of steel. As standards get tighter, coil losses will also need to be reduced by making them tighter and take up less space and will require better coil winding machines and processes. Not a lot has happened in the transformer coil winding industry for a long time so developing the knowledge base of how to wind coils tighter so they use less space might be a challenge but once they figure it out, then it is an excellent opportunity to team up with transformer designers and sell some higher value equipment. Electric motors, where the conductor is packed in slots in the stator, may be a good source of inspiration for transformer applications," Sampat explains.

"I see no end to the technology development possibilities, although it may become increasingly difficult to continue to make such big efficiency gains," Pollari adds.

"Regulation is not a problem but an opportunity to advance the level of the market," Baggini concludes. "Traditionally the EU has been the technology leader within the transformer manufacturing industry. Standards are being introduced all over the world and through the new MEPS, we are already encouraging the entire transformer manufacturing supply chain to be forward-looking once more and maintain a profitable global position in the future."

Mahesh, Pollari and Baggini will be discussing these points and more in a panel discussion, entitled ‘New EU regulation on transformers - background, ruling and industrys response, at the forthcoming CWIEME Berlin exhibition for coil winding, insulation and electrical manufacturing. Their session will take place at the CWIEME Central theatre 15:45-16:25 on Tuesday 10th May and is free for all visitors to attend. There will also be opportunities to ask questions face-to-face after the session.

CWIEME Berlin
Dates: 10-12th May 2016
Venue: Messe Berlin, Messedamm 22, 14055 Berlin, Germany
Opening times: Tuesday and Wednesday 09:00-18:00, Thursday 09:00-16:00
Admission: An on-site registration fee of €40 will apply for those who have not already registered online.