Patent ID: 6914420
Filing Date: 2005-07-05
Classification: H02M

Abstract:
1. A power converter for controlling power flow between first and second voltages, the power converter comprising: a common connection between a first polarity of the first and second voltages; a capacitance coupled at a first electrode to the common connection and having a second electrode; first and second switches, linked at a connection which when switched on conduct current bi-directionally and when switched off operate like a semiconductor diode, connected in series between the common connection and the second electrode of the capacitance; third and fourth switches, linked at a connection which when switched on conduct current bi-directionally and when switched off operate like a semiconductor diode, connected in series between the common connection and the second electrode of the capacitance; a first inductance coupled between a second polarity of the first voltage and the connection linking the first and second switches; a second inductance coupled between the second polarity of the second voltage and the connection linking the third and fourth switches; and a controller, controlling operation of the switches to control power flow between the first and second voltages; in which the converter has a first mode of operation when the controller causes the first switch to be open, the second switch to be closed, and the third and fourth switches to switch alternately, the second voltage being less than the first voltage, a second mode of operation when the controller causes the first and second switches to switch alternately, the third switch to be closed and the fourth switch to be open, the second voltage being greater than the first voltage, and a third mode of operation when the controller causes the second and fourth switches to be closed, and the first and third switches to be open, the first and second voltages being equal.