Tristate Modified Boost Converter

Abstract:
When the position of the capacitor in a Boost converter is changed from the output to bridge the positive input connector with the positive output connector, two interesting features occur: the voltage stress of the capacitor is reduced and the inrush current is avoided, when the converter is applied to a stable DC supply. Using the tristate concept, the active switch of the converter is replaced by a combination of two electronic switches and a diode. The two electronic switches are connected in series and an additional diode is connected to the connection point of the switches. Now, further interesting and helpful features occur. The voltage transformation ratio is linearized and the converter becomes a phase-minimum system, when the duty cycle of the second switch is held constant. The stress of the active switches is also reduced.