A systematic control-loop design procedure for a multimodule converter system for high-current, low-voltage applications is presented. A small-signal model of the system is derived using the PWM (pulse width modulation) switch model and the small-signal model of the current mode control. The small-signal model for the multimodule converter system is simplified to a equivalent single-module model. The control-loop design is implemented using the single-module model. A three-loop control strategy for the multimodule converter system with a secondary output filter is developed. Significant improvements of small-signal performance and module-failure response are achieved using additional feedback from the intermediate filter stage. The small-signal analysis of the three-loop controlled converter is performed, focusing on the effects of the local voltage feedback on the closed-loop performance of the system. It is shown that local voltage feedback minimizes any detrimental effect of the resonance between the power stage filter of each converter module and the common output filter.<<ETX>>
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