Onshore Wind Turbines

MIDEL 7131 plays an important part in onshore wind applications because it offers advantages over other liquid-filled and dry type options.

A major benefit of using MIDEL 7131 is increased fire safety. The fire point of mineral oil in conventional transformers is approximately 170°C; whereas with MIDEL 7131 it is in excess of 300°C. MIDEL’s fire safety may lead to a reduction in the requirements for additional fire protection.

MIDEL-filled systems are not as susceptible to damage from vibrations and harmonic frequencies as dry-type solutions. Dry-type transformers can also suffer from sensitivity to water, micro-cracks, temperature variations, load fluctuations and pollution. Furthermore, a dry-type transformer cannot be made as compact as a MIDEL 7131 filled system – a challenge where space is limited.

Offshore Wind Turbines

Operating offshore presents its own unique challenges for experts, with dependability and safety being paramount. Potentially corrosive atmospheres challenge reliability, and failures can result in expensive unplanned maintenance. It is therefore essential to specify a robust, oxygen stable liquid such as MIDEL.

MIDEL 7131 is the most popular dielectric fluid in this demanding arena, with a robust reputation as a fire safe, high performance transformer fluid.

Offshore Substations

Substations provide the vital link between wind turbines and the electrical grid. As wind farms move further offshore, substations are positioned on purpose-built platforms – offering challenges including transformer fire safety and maintenance costs.

Offshore transformer fires are difficult to combat and could result in the wind farm being shut down. Filling a system with MIDEL 7131 instead of mineral oil increases fire safety because MIDEL 7131 has a much higher fire point (>300°C) and a 100% fire safety record. Furthermore, by specifying MIDEL 7131 has proven possible to design significantly smaller offshore substations, without complicated transformer fire suppression.

In offshore substations a transformer’s performance is just as important as its fire safety. If the transformer fails to withstand the corrosive atmosphere it will need to undergo expensive unplanned maintenance – specifying a fluid such as MIDEL that is extremely robust, oxygen stable and proven to work means greater assurance for operators.

Case Study: Siemens offshore transformer

Benefits of MIDEL 7131 in Onshore Wind Transformers

Increased Fire Safety
  • K-class high fire point (>300°C) to IEC 61039
  • 100% fire safety record
  • Suitable for installation within a turbine
  • FM® approved and UL® listed transformer fluid
High Performance
  • Robust and stable, conducive to lower levels of maintenance
  • High temperature performance allowing for compact transformer designs
  • Greater moisture tolerance than mineral oil, silicone liquid and natural ester
  • Excellent reliability
  • Lower no-load losses than cast resin transformers; reducing energy consumption in low wind conditions
Greater Environmental Protection
  • Readily biodegradable according to OECD 301 and fully biodegradable according to IEC 61039
  • Non-toxic
  • RoHS compliant