Development trends of dry transformers

In the power system today, for every kW of power generation capacity should have about 5 - 6KVA capacity transformers. Power losses in the transformer accounting for nearly 30% of all electricity losses in the grid. Therefore transformer is one of the essential components of the power system, which is crucial to our economy.

Until the late 20th century, nearly all of the transformers are of the type of transformer oil, oil which acts as both support cooling coils, moderate increases their dielectric strength.

Oil quality directly affects the reliability, service life of the transformer. In the course of operation need to regularly monitor the status of oil to promptly detect changes in the properties of the oil through the identification of a range of important indicators such as mechanical impurities and suspended carbon, reliable insulation, acid index, a flash point of the oil temperature, viscosity, clarity, stability, dielectric loss angle ... To manage oil quality should be equipped with more technical means, first required management personnel, skilled technical staff, skilled workers ... On the other hand, with a large number of transformer oil, the risk of fire and explosion is always permanent, threatening equipment failures and cause accidents to people, the environment pollution.
In the 50s of the last century, some countries have turned to using some oils and fire control. Among them are mostly chocolate oils which are very toxic and do not decompose. Since 1970 the said oil has been banned from use due to its toxicity adversely impact human health and the environment, even if the oil content in the chocolate capital of small and conventional transformer oil.

Important disadvantages of transformer oil as described above is the risk of fire or explosion. Hence an inevitable problem arises must seek to eliminate the potential risk that: manufacture transformers no oil, but experts known as dry transformers.

Actually the idea of ​​making dry transformers had from the first half of last century, but at that time the conductive materials, insulation, steel from ... the protective equipment, measurement and control also backwardness does not allow development of dry transformers as in recent years. Today, Dry transformers are used more and more because of the following factors: