New Iron-based Alloy Promises Reduction in Transformer Core Loss

by Mar 24, 2017

Russian scientists have found that a new iron-based alloy could reduce energy loss inside transformer core and motors.

Impression: After transmission lines, transformers are the second largest source of losses in electricity grids. Distribution transformers alone account for approximately one-third of global network losses. Transformer losses are separated into two categories:
• Winding loss (Load loss or Copper loss)
• Core loss (No-load loss or Iron loss)
Winding loss:
As the name suggests, this loss occurs in copper windings of a transformer due to inherent resistance of conductor. Increasing the cross-section of the winding results in reduced load loss.
Core loss:
Core loss arises within magnetic core of a transformer due to characteristic hysteresis action and flow of eddy currents. There are two possible remedies for transformer core loss:
1- Increasing cross-section of magnetic core
2- Use of higher grade core material

In the recent past, there has been considerable amount of research done to develop better quality electrical steel for transformer cores. Recently, one such material was developed by a team of Russian scientists. According to the researchers from Advanced Energy-Efficient Materials Lab at the National University of Science and Technology MISIS in Moscow, this amorphous alloy with unique specifications is expected to reduce transformer losses by 66 percent which, for a MV transformer (6.6kV/220V), translates to annual power saving up to 16.3 MW.
This has significance with regards to efficiency regulations being enforced on transformers, for example EU’s Eco-design directive. The Eco-design directive is a set of region-wide regulations enforced by European Union with an aim to improve the energy efficiency of the electrical equipment including transformers and motors, hence reducing the CO2 footprint. In 2015, first phase of directive for transformers was introduced, which enforced all future installations to comply with the specific core and winding loss regulations. The second phase of the directive is expected to take effect in 2021 with 10% stricter loss requirements. According to MISIS lab, this new iron-based core material can easily fulfill phase-2 loss requirements. Assuming 6kV transformers average capacity rating at 500 kVA, potential benefit of new core material with respect to Eco-design directive regulations can be presented as:



Thus, PTR anticipates that European transformer market is most likely to gain maximum benefit, if the new core material clears experimental stages and successfully enters the large-scale production phase. In order to observe more quantitative results, PTR has extrapolated the potential impact of the new core material on EU’s 6kV transformers market to achieve possible annual power savings in GW. This analysis assumes that all 6kV/LV transformers installations in 2017 will utilize new core material.

Link to press release: Reduction in core losses