| The automobile industry is currently using the 14V claw-pole synchronous generation system. With the increase of the equipments on automobiles the 14V system is hard to meet the needs of electricity for its low efficiency. The 42V power generation system replace the 14V power system has become a trend. With the 42V electrical system, automotive generator output power and efficiency can be greatly improved. Compared to synchronous generator, induction generator is simple in structure, with low maintenance costs and price advantages. Automotive power system using induction generator can improve reliability, and cost saving.This thesis proposed a novel control of 42V automotive induction generator system based on vector control, direct torque control and PWM rectifier direct power control. Firstly, the models of the induction generator, PWM rectifier and battery, are presented. Analyzed the direct DC current control system based on the direct torque control. Secondly, a special attention is paid to the analysis of direct power control strategy. The stator flux, speed and instantaneous active power are estimated according to the AC current sensor, DC voltage sensor and switch signal. So there's no AC voltage sensor and speed sensor. By regulating the generator output instantaneous active power and stator flux, and by using predicted load feed-forward-control scheme, the system can output stable 42V DC voltage and suppress the dynamic voltage effectively during load-dump and jump-start charging at varying speed conditions. The control strategy can avoid the weaknesses of vector control which being hard to observe and complex to calculate and sensitive to generator parameters, and the weakness of direct torque control with the switching frequency being unstable and high sampling frequency. The dSPACE based real-time simulation results verify the validity of the proposed method.
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