A Novel PDM Control Strategy for Voltage-Source Modular-Structured Resonant Converters

Pulse density modulation (PDM) has been widely explored for voltage-source series-resonant converters. However, the use of this modulation leads to amplitude fluctuations of the converter’s output current, which, as a consequence, leads to various problems. Enhanced PDM control methods and hybrid approaches have aimed to address this issue, but not without difficulties. Modular-structured converters with interleaved and stepped PDM control techniques have been proposed as alternatives, offering their own advantages. This chapter introduces an innovative PDM control strategy that combines interleaved and stepped PDM techniques with augmented PDM principles to minimize current amplitude fluctuations in modular-structured series-resonant converters. Comparisons with existing methods show a reduction in fluctuations, albeit with increased complexity. The choice of strategy depends on the specific requirements of the system, with the proposed approach offering a solution for reducing current amplitude fluctuations.