Abstract: The invention discloses a bidirectional dc-dc converter system and circuit thereof. In boost mode, topology is combined with interleaved two-phase boost converter for providing a higher step-up voltage gain. In buck mode, topology is combined with interleaved two-phase buck converter in order to get a higher step-down conversion ratio. The main objectives of the invention are aimed to both store energy in the blocking capacitors (C1&C2) for increasing voltage conversion ratio and reduce voltage stresses of active switches simultaneously. As a result, the invention topology possesses a nice low switch voltage stress characteristic. This will allow one to choose lower voltage rating MOSFETs to reduce both switching and conduction losses, and overall efficiency can be enhanced. In addition, due to charge balance of the blocking capacitor, the converter features both automatic uniform current sharing characteristic of interleaved phases and without adding extra circuitry or using complex control methods.

Abstract: A bidirectional converter circuit includes a voltage source which provides an input voltage, an energy storage set connected to the voltage source and receives the input voltage, a switch set connected to the energy storage set, wherein the switch set includes a first switch and a second switch; an operating switch set connected to the switch set, wherein the operating switch set includes a first operating switch, a second operating switch, a third operating switch and a fourth operating switch. The bidirectional converter further includes a blocking capacitor set and a (input/output) capacitor set. Wherein, the blocking capacitor set is connected to the switch set and the operating switch set. The first operating switch and the second operating switch are driven complementarily with the first switch, and the third operating switch and the fourth operating switch are driven complementarily with the second switch.