Three-phase transistor inverter for low voltage, high current, battery fed applications

AC inverters are increasingly being used for traction drives. The authors describe the practical development of a 3-phase inverter for a low voltage traction application. The practical prototype was designed for an 84 V supply with a 350 A peak sinusoidal current rating. The various aspects related to the power electronic design are discussed. Bipolar transistors were chosen for the main switching devices. Efficiency was the main reason for this choice, owing to the difficulty of cooling and the limitation on size in all the low voltage, high current applications