Making power transformers more sustainable

The huge development and progress in the transmission and distribution of electrical energy during the past 130 years was made possible by the power transformer . Such critical component is capable of efficient and reliable linking generation via transmission and distribution to the loads, at each stage operating at its most suitable voltage.

Transformer design and manufacturing is a complex process considering dielectric, electromagnetic, thermal, mechanical, and environmental aspects , several of which are interrelated.

Indeed, due to the sustainable energy transition and increasing electrification a rapid expansion of the grid is needed, the share of electricity in the energy mix is expected to more than double in the year 2050. For power transformers, this implies that, for example, increased plug-and-play provisions like plug-in- bushings and cable connectors are employed and even temporary (mobile) transformer substations are asked for mitigation of bottlenecks in the grid.

From the perspective of “ greening the grid ”, the loss-reduction of transformers is very important (see e.g., EU-directive 2019/1783 of 1 October 2019 with amendments). To comply to this directive, transformer manufacturers must use thinner core material , a lower current density in the windings and/or use thinner strands and find engineering solutions to reduce the other losses like stray losses but also power needed for the pumps and fans. Noise reduction especially in densely populated areas is a very important topic, measures taken at the transformer or sound enclosures are possible, having both pros and cons concerning e.g., price, cooling and accessibility.

The predominant cooling and insulating liquid used in (large) power transformer is oil that is flammable and poses environmental risks when leakage or spills occur. This can be mitigated but not entirely prevented, for this reason bio-degradable and more environmentally friendly liquids are being developed and piloted .

In this respect, KEMA Labs is working on tests and new test requirements to assist its customers in ensuring not only a sustainable, but also a reliable and safe electrical power system. For more information about this, you can click on this link .