SGB massively reduces no-load losses - thanks to exclusively used core material

Since SGB Regensburg started series prodcution of oil distribution transformers after its foundation in 1947, the basic functional principle of the transformers from Regensburg has not changed.

In contrast, the group member can look back on a whole series of innovations and improvements in transformer design and technical implementation.

In the case of cast resin transformers, for example, this includes the SGB Safe System for the protection of people and the environment, the SGB Jet System cooling system or a layer winding used exclusively by SGB. In addition, over the decades, SGB transformers have been continuously optimised in those areas to which our customers attach particular importance, namely

  • Climate resistance
  • Environmental protection
  • Lifetime
  • Service-friendliness
  • Transformer dimensions
  • Economy


Now SGB Regensburg has achieved a breakthrough in the last two points that has been noted throughout the industry: The SGB-SMIT Group has gained unique access to the top grade in the electrical steel sector and can now offer electrical steel of grade M070-23P, a core material with very special properties, on a broad scale in the cast resin sector. In contrast to conventionally used steel grades, which for example have a loss value of 1.2 W/kg at 1.7 T and 50 Hz, this value is only slightly more than half as high, namely 0.7 W/kg at 1.7 T and 50 Hz. Even the previous standard grades in the 0.23 mm thickness range generally provide a loss value of at least 0.8 W/kg. 

By using this top grade, we can keep no-load losses by a further 10% lower than all other conventional electrical steel available on the world market without negatively affecting productivity.

For the customers of SGB Regensburg this results in two significant advantages:

  • For the same size, a transformer produced with this material has significantly lower no-load loss values and thus achieves increased efficiency.
  • Conversely, for a given loss target, transformers can be produced with a smaller size and less weight, since comparatively less core material is required to achieve the target values.


Depending on which factor is important for the customer, SGB Regensburg can thus act even more flexibly and customer-oriented in the transformer design thanks to the new development (M070-23P).

SGB Regensburg is currently producing a transformer with a rated output of 1,750 KVA and no-load losses of only 1,500 W. For comparison: At this output, the ECO design guideline stipulates a maximum of 2,350 W according to stage I and a maximum of 2,115 W according to stage II. Even the Eco 2 losses, which will not apply until July 2021, are thus undercut by around 30%.