Transformers for Wind and PV Generation

Trafoexperts Transformer Consulting Services

Renewable energy generation is spreading worldwide at increasing rate. With more and more wind and PV generation farms, we see a corresponding increase in wind and PV generation transformer failures.

Difference from distribution transformers

These transformers are considered distribution transformers because of their rating (up to 3400kVA) and voltage (up to 33kV). However, the service conditions for wind and PV generation transformers are considerably more severe than those of distribution transformers in terms of:

  • voltage and current harmonics
  • load cycles
  • DC voltage bias
  • system transients
  • high dv/dt from the inverters connected to them
  • etc.

In addition, wind and PV generation transformers must be much more reliable than distribution transformers because of lack of redundancy and the financial consequences of a failure.

Unfortunately, many transformer manufacturers build wind and PV generation transformers like distribution transformers. This regularly results in abnormal gassing (several thousands of ppm of hydrogen in oil is not rare at all) and in failures.

Our added value

Our transformer consultants deal with wind and PV generation transformer diagnostics and failures on a regular basis around the world. We have experience not only in diagnosing problems in these units but also in what to change in the design and manufacturing process in order to solve the problems we have observed.


Our consulting services

Our transformer consultants provide the following services:

  • Assessment of the current design and production capabilities of a transformer manufacturer to determine whether it is qualified to produce wind and PV generation transformers. If the order has already been placed, this assessment can be used to prevent the production of non-reliable transformers.
  • Providing training to transformer manufacturers so that they can acquire the knowledge needed to produce reliable and non-gassing wind and PV generation transformers covering all aspects (design, production, treatment, testing, sourcing of sub-components and transport).
  • Diagnostics of wind and PV generation transformer fleets to identify units at risk of failure.
  • Forensic failure analysis to determine the root cause of a failure and determine corrective measures to maximise the reliability of the surviving transformers.
  • Assistance to your legal team in case of litigation following the failure of multiple transformers.
Dr. Ing. Ugo Piovan

Dr. Ing. Ugo Piovan

Transformer Consultant
Trafoexperts GmbH

Turbinenweg, 4
8610, Uster, Switzerland