| Today's automotive electrical power system, which is rectified at 14 V by diode bridge and charges a 12 V battery and delivers power to the electrical loads, is based on an engine-driven alternator. These 14V power systems have disadvantages with low power capacity and low efficiency. In order to meet the demand of higher electrical power and fuel efficiency in automobiles, a 42V claw-pole generation system is presented.In the present thesis, a special attention is paid to the system models and voltage control schemes. The models of claw-pole generator and PWM rectifier and other devices are proposed. The controllers are designed in details. It must be emphasized that the claw-pole generator is modeled with dq model in the generating direction and the vector control technique is applied in the system.In order to improve the performance of generator system, a control scheme by using AC electromotive force and DC voltage is presented. The field current loop is regulated during speed varying. It can regulate AC electromotive force with DC voltage stabilized at 42V. The phase current and DC voltage controllers are used, the phase current loop as inner loop, and DC voltage loop as outer loop. The DC output voltage of rectifier is regulated based on field-oriented control principle to improve the suppression of dynamic voltage during load-dump or jump-start charging. In order to minimize the DC-link capacitance for compaction of the system, a load current prediction feed-forward control approach is proposed. The proposed approaches are evaluated by the experimental results.
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