Design of multiple conversion ratio and bidirectional power flow by using dual SC DC-DC converters

This paper presents the simple design technique to implement dual SC DCDC converters that can convert input voltage step up or step down. The output of proposed converters is connected between individual converter output capacitors so that the output voltage can convert to multiple levels step up or step down and bidirectional power flow. The conversion ratio can be specified by simple circuit structure by connecting the capacitors in parallel or series. The circuits are designed by digital technique to on-off the switches for step up or step down conversion ratio 1x, 2x, 3x, jx, or 1x, 1/2x, 1/3x, 1/jx, respectively. The characteristics of the proposed converter are clarified by theoretical analyses. In addition, experimentation shows the validity of circuit design, where theoretical results correspond well with experimentation results. The proposed converter will be useful as a driver circuit for battery charger and power battery transfer between different level voltages. © 2013 ICIC International.