Converters with Reduced Duty Cycle Range and Ground Connected to the Positive Input Voltage Terminal

A family of converters with reduced duty cycle range is treated here. Two-step-down, two step-up, and four step-up-down converters are investigated. Four different voltage transformation ratios can be found. For all converters, the large signal and the small signal models of the ideal case are given. Furthermore, the connections of the operating point values and the voltage stress across the semiconductors are indicated. Simulations for the steady-state are shown. A method to calculate the transfer functions is proposed and one transfer function for type 1 is shown as an example. The inrush current, when the converter is connected to a stiff input voltage source, is studied with the help of calculations, and time- and phase-diagrams. Several variations and combinations are also shown.