A compact 480V 700hp induction motor drive using Darlington transistors

Bipolar transistors have been used very successfully in variable frequency induction motor drive equipment. The author describes a practical approach to paralleling bipolar 600 A transistor modules in order to produce a 700 hp 480 V equipment. Emphasis is placed on the base drive circuitry, the methods of controlling parasitic inductance in the power circuit and the mechanical arrangement of the equipment