A Family Of Four-Quadrant, PWM DC-DC Converters

A new family of bi-polar bi-directional DC-DC converters is generated by using two symmetrical basic blocks, each one formed by a switch, two inductors and two capacitors. The converters provide a reversible output voltage, greater or smaller than the line voltage. Both the direction and the value of the load voltage is dictated by controlling a single parameter: the duty-cycle of the two main switches. The switching operation is very simple: two topologies per cycle, obtained with a PWM controller. The propose converter allow to get extremely low output voltages at the duty ratios near 0.5.