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Specialist Materials for Industry and Science

Offshore Wind Energy

Offshore Wind Energy

Offshore Wind Turbine Transformers

Offshore wind energy is a relatively new concept, and MIDEL 7131 is already being highlighted as the most popular dielectric fluid for these demanding jobs. Its reputation is testament to MIDEL 7131's proven track record as a fire safe, high performance transformer fluid.

Operating offshore presents its own unique challenges for experts, with dependability and safety essential. Potentially corrosive atmospheres test reliability, and failures can result in expensive unplanned maintenance. It is therefore essential to specify a robust, oxygen stable fluid with a long, successful history.

Benefits of MIDEL 7131 in Offshore Wind Transformers

Fire Safety

Fire safety is a crucial factor for wind turbine transformers, and Midel offers the perfect transformer fluid for this. At >300°C, MIDEL 7131 has a much higher fire point than mineral oil, and its 100% fire safety record greatly reduces the risk to your transformer. It is an FM Global® and UL® listed transformer fluid that is perfectly suited to installation within a turbine.

High Performance

Using MIDEL 7131 has advantages in comparison to installing dry-type transformers because its properties allow for a more compact design, important where space is limited. MIDEL 7131 filled transformers are also not as susceptible as dry-type systems to damage from vibrations and harmonic frequencies or as sensitive to water, micro-cracks and pollution.

Other qualities that help to maintain the high performance of MIDEL 7131 in wind turbine transformers include:

  • Robust and stable at high temperatures over long periods
  • Suitable for use in hybrid and aramid designs
  • Allows for compact design; ideal for installation in tower or nacelle
  • Very low pour point (-60°C)
  • Self healing
  • Lower no-load losses than cast resin transformers, reducing energy consumption in low wind conditions
  • Excellent lubrication properties
  • Greater moisture tolerance than mineral oil and natural ester
  • No corrosive sulphur
  • Proven up to 238kV in power transformers

Greater Environmental Protection

Reliability is undoubtedly paramount when it comes to transformer insulation, but in a clean technology sector such as wind energy they should also be environmentally sound. In this respect, fluids such as mineral oil cannot compare to MIDEL 7131 because it is readily biodegradable according to OECD 301 and fully biodegradable according to IEC 61039, and classified as non-water hazardous by UBA.

Furthermore, it is non-toxic, not harmful to aquatic life and recoverable and dispersible at sea using standard methods, highlighting MIDEL 7131's suitability for offshore wind turbine transformers.

Excellent Customer Service

At Midel, we pride ourselves on our first-rate customer care, with our multilingual commercial team of transformer fluid experts providing technical support for all clients.

For more information please see our Documents or Contact us.



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