High Voltage Equipment (HVE) has started to adapt its instrument transformer range to use environmentally-friendly ester fluid in place of mineral oil as their insulating medium.
“We have developed and tested the first of these, an 11kV pole-mounted ester fluid insulated metering instrument transformer, which we unveiled on ACTOM’s exhibition stand at Electra Mining Africa 2022 in Johannesburg in early-September this year, where it was well-received and evoked a lot of interest,” said Etienne Venter, HVE’s Senior Design Engineer, who led the team responsible for designing the new product.
The changeover to ester fluid will be applied progressively in coming months up to mid-2023 to the division’s entire instrument transformer range, which comprises current transformers, voltage transformers and various types of metering instrument transformers of between 3,3kV and 132kV.
“We will continue to offer and supply conventional mineral oil insulated units to the market, but expect our new ester fluid filled units to be widely adopted. Demand for them is likely to increase steadily over time – especially among power utilities, municipalities and the renewable energy sector – in line with the accelerating worldwide trend towards the decarbonisation of transmission and distribution equipment,” Etienne commented.
Ester fluid is a biodegradable and high-level dielectric insulating fluid. Its positive features from both environmental and performance viewpoints include:
- It reduces the risk of environmental damage in the case of spillages.
- It is recyclable at the end of the service life of the equipment, resulting in low disposal costs.
- It offers a higher flash point than mineral oil, resulting in nil risk of a fire in the event of a major failure of the equipment.
- It has a high temperature stability, so can be subjected to high temperatures for longer than mineral oil.
- It has higher thermal conductivity than mineral oil, making it better suited for regulating transformer temperatures.
- It promotes extended asset lifetimes, due to the slower aging rate of the cellulose paper in a transformer. It draws moisture out of cellulose insulation, thereby extending its life.
