A 4 kW, 42 V induction machine based automotive power generation system with a diode bridge rectifier and a PWM inverter

In recent years, the electrical load demand in automobiles has been increasing steadily due to the usage of several subsystems to improve engine performance, passenger comfort and safety. The current production Lundell alternator is not able to meet the future growing power demand due to its inherent design limitations. Therefore, an efficient, high power generation system is needed to meet the growing electric power demand in automobiles. The recent trend to adopt the 42 V power system in automobiles allows one to add more subsystems in an efficient way. In this paper, a three-phase, 42 V, 4 kW, induction machine based automotive power generation scheme is proposed to meet the future electrical power demand in automobiles. This scheme uses a low cost diode bridge rectifier directly connected to the induction machine to transfer active power to the battery and the load. The excitation to the machine is supplied by means of a low power PWM inverter to control the output voltage of the generator connected to the diode bridge rectifier. This paper presents a new control methodology to regulate the output voltage of an induction generator directly connected to a diode bridge rectifier by controlling the auxiliary PWM inverter. The simulated performance results of a 4 kW, 42 V induction generator scheme at various speeds and loads are presented.