Patent ID: 6633107
Filing Date: 2003-10-14
Classification: H01F

Abstract:
An electrical transformer comprising:a tank containing transformer fluid; a transformer core and winding subassembly disposed in said transformer fluid within and spaced apart from said tank; and active means for varying a volume of said transformer fluid in order to reduce pressure waves generated by a vibration of said core and winding subassembly during electromagnetic operation, said active means being disposed in said transformer fluid within said tank, wherein said active means comprise at least a cell having: a main body and a corrugated membrane operatively connected to said main body in order to realize a sealed container able to maintain a low pressure atmosphere inside said container, and actuating means placed inside said sealed container and solidly connected to said corrugated membrane for vibrating said corrugated membrane to generate pressure waves to change the volume of said transformer fluid in proportion to an amplitude and frequency of the pressure waves generated by the vibration of said core and winding assembly.