Use of gas-filled power transformers in urban areas is accelerating

The IEC published in February a new International Standard in the bestselling IEC 60076 series on power transformers. Dealing with gas-filled power transformers, IEC 60076-15 is expected to be as successful as the other parts of the series.

A gas-filled transformer is a transformer whose magnetic circuits and windings are enclosed with an insulating gas. Sulfur hexafluoride (SF6) gas is generally used. Such a transformer is sometimes referred to as a gas-insulated transformer.

Katsutoshi Toda of Toshiba Corp, who is TC 14, Power transformers Project Leader for IEC 60076-15 said: “Australia and the United Kingdom are already among the countries that use these transformers. There has been a rapid increase in gas-filled transformers and reactors, particularly in South-East Asian countries like Japan, China, Hong Kong, Singapore and Korea. Plans to construct indoor or underground substations accelerate this trend because of the difficulty in acquiring land for substations in large cities where electric power demand is concentrated. Requirements of security against fire accidents, compactness and total cost reduction are the key factors for these substations. Total gas-insulated substations (GIS) combining GIS and gas-filled transformers meet these needs.”

Katsutoshi Toda’s views are corroborated by a United Nations report* published also in late February. The report forecasts that half the world’s population will live in urban areas by the end of 2008 and about 70 percent will be city dwellers by 2050, with cities and towns in Asia and Africa registering the biggest growth. By 2050, the world's total population is expected to rise to 9.2 billion from the current 6.7 billion, with 6.4 billion people living in cities, up from 3.3 billion now.

One consequence of this urban population growth will be a huge increase in electric power demand, particularly in the densest areas. To meet this need, authorities and utilities will have to implant new substations. Because city land is scarce and expensive, many of the new substations will be built indoors or underground. At the same time, the demand for gas-filled transformers is expected to increase.

"Australia and the United Kingdom are already among the countries that use these transformers", Toda said.  "Gas-filled transformers (up to 330 kV-400 MVA class) are currently operating in the field of electric power utilities and industrial firms".

IEC 60076-15, Power transformers – Part 15: Gas-filled power transformers is an essential tool for those who design, construct, purchase or operate gas-filled transformers and for those who plan or construct the substations in dense city areas.

* World Urbanization Prospects - The 2007 Revision, United Nations, Economic & Social Affairs Division, 2008-02-26