On the use of silicone liquids in power transformers

Abstract

The insulation and basic physical characteristics of insulation liquids MIDEL 7131 (ester) and SOFEKSIL–TSZh (silicone liquid) are considered. It is shown that the SOFEKSIL–TSZh liquid is characterized by a higher flash point, which is important for providing the fire safety of high-voltage electrical equipment. Taking into account that contradictory data on the electrical strength of silicone liquids are contradictory, studies on the electric strength of the SOFEKSIL–TSZh liquid and transformer oil have been performed for sharply nonuniform fields at an impulse voltage of 1.2/50 μs for both polarities. It is shown that the electric strength of the SOFEKSIL–TSZh liquid is similar to the electric strength of GK transformer oil and MIDEL 7131 liquid. It is concluded that the SOFEKSIL–TSZh liquid can be used in power transformers in the case of increased requirements for fire safety.