Patent ID: 7471534

Claim:
Inverter type motor drive unit for feeding AC electric power of variable parameters to an electric motor, comprising: an electronic control section ( 40 ), a power converting and output section controlled by the control section ( 40 ), two input terminals ( 25 , 26 ) for connection to a DC power source, and three output terminals ( 32 , 33 , 34 ) for delivering a 3-phase AC power to said electric motor, wherein the power converting and output section comprises: one or more identical power modules ( 11 a - 11 c ), each comprising a complete 3-phase output stage, said one or more power modules ( 11 a - 11 c ) are multiplied by a suitable number and interconnected in parallel to meet the power demand of the actual motor size, and wherein: said one or more power modules ( 11 a - 11 c ) are mounted side by side in a multiplying direction (A) on a cooling structure ( 10 ), thereby covering a certain surface area substantially corresponding in size to the surface area covered by the actual number of power modules ( 11 a - 11 c ), and said one or more power modules ( 11 a - 11 c ) are connected to said DC input terminals ( 25 , 26 ) and said AC output terminals ( 32 , 33 , 34 ) via conductive layers ( 20 , 21 , 27 a - 27 c ) which are electrically insulated from each other and extend substantially in parallel with said cooling structure ( 10 ) and covering substantially all of said certain surface area.