Moisture-equilibrium charts

Moisture-equilibrium charts

Vol. 4 Issue 2


Green transformers, a sustainable and environmentally-friendly range of power transformers, are gaining in popularity. The growing interest in such transformers is linked to the introduction of innovative technologies, such as natural esters (biodegradable and renewable liquid offering higher fire safety) combined with a sealed design, to be used instead of classical mineral oil. For efficient and accurate moisture-condition monitoring, green transformers need moisture-equilibrium charts. In-depth experiments have been carried out to produce and validate such charts, similar to those existing for mineral-oil-filled transformers.

Keywords: green transformer, natural ester, moisture-equilibrium charts, cellulose


1.      GREEN POWER TRANSFORMERS (from 10 to 500 MVA and up to 550 kV)

Today it is taken for granted that power transformers are robust pieces of equipment designed to ensure long lifetime, safety, low weight, compactness and cost-effectiveness. On top of that, it is expected that they will meet the requirements for high efficiency, noiselessness and environmental friendliness. This is the reason why green transformers [1], a sustainable and environmentally-friendly range of eco-efficient power transformers with innovative technical characteristics, have been developed (Figure 1). To enable this, modern technologies, such as biodegradable insulating liquids based on natural esters combined with a hermetically-sealed design, are available today. First successful operating experiences of power transformers have already been gained.


Perrier Figure1

Figure 1. New and innovative green transformer generation: key areas of development to support eco-friendly solutions