Electricity and Control June 2020

TRANSFORMERS, SUBSTATIONS + CABLES

A new high performance bio-based transformer fluid

By Carl Wolmarans,Technical Advisor, Electrical Industry at Nynas

The electricity network today is facing two significant challenges. On one hand, the classical model of generation and distribution is evolving with the rapid adoption of renewables and ‘prosumers’. This is placing greater strain on existing equipment in the form of more frequent load swings and overloading. On the other hand, the energy sector as a whole is under increased scrutiny regarding its environmental impact.Within the power transformer space, Nynas has recently launched a game-changing product ideally suited to help address these challenges.

N YTRO ® BIO 300X, the result of years of intensive research by Nynas, is a renewable hydrocarbon- based insulating fluid with outstanding performance characteristics and is also readily biodegradable. The product meets and exceeds the IEC 60296 specification and has best-in-class cooling properties. NYTRO BIO 300X will provide enhanced cooling in a transformer, leading to reduced winding temperatures, due to its ultra-low viscosity. The temperature of a transformer and particularly its windings are critical parameters and temperature reduction (through improved convective cooling) provides several

The ideal application areas for NYTRO BIO 300X are offshore transformers, mobile transformers, in sensitive environments, in projects where weight and size constraints need to be accommodated, as well as with renewable energy generation. In wind and solar farms, transformers using NYTRO BIO 300X deliver environmental and performance demand synergies. For mobile substation transformers, furnace transformers and highly loaded units (units requiring overload ratings) the bio-based fluid meets the units’ high thermal demand. The use of NYTRO BIO 300X supports lower total cost of ownership on transformers as a result of lower maintenance requirements on the insulating liquids and lower temperatures promoting lower ageing and lower load losses in the equipment. At a glance ■  NYTRO ® BIO 300X is a renewable hydrocarbon-based insulating fluid that, due to its ultra-low viscosity, provides enhanced cooling in a transformer, leading to reduced winding temperatures. ■  With a bio-based carbon content of more than 99% it is also readily biodegradable. ■  This new transformer fluid supports lower total cost of ownership on transformers.

advantages. These include: - Overloading capability - Size and weight reduction - Better distributed heat during load swings - Cooling system optimisation - Load loss reduction - Operating temperature range flexibility - Longer transformer life.

NYTRO ® BIO 300X is readily biodegradable when tested to the strict criteria in OECD 301. It also has a bio-based carbon content (tested to ASTM D6866) of more than 99%. A key technical achievement with this novel insulating fluid is that it meets these criteria while also achieving outstanding oxidation stability – and therefore no special handling is required, and it is fully suited to free-breathing transformers. In addition, maintenance and monitoring is fully in line with practices used for inhibited mineral insulating oils. Perhaps the single most important aspect of NYTRO BIO 300X is that it requires few or no design adaptions on the power transformer. This is due to its sharing a very similar chemistry to mineral insulating oils. It means that customers can benefit from the product’s biodegradability and enhanced cooling with little hassle, a particular benefit when contrasted with ester-based insulating fluids which have very different physio-chemical properties and usually require significant design adaptations on the transformer.

Due to its ultra- low viscosity, NYTRO BIO 300X provides for enhanced cooling in transformers.

Electricity + Control JUNE 2020

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