Patent ID: 6246599
Filing Date: 2001-06-12
Classification: H02M,Y02B

Abstract:
A full bridge, resonant, constant-frequency, phase-shift-controlled, dc to ac inverter comprising in combination:a coupled inductor having first and second winding, said first winding and said second winding connected in series forming a common terminal of said coupled inductor;two pairs of series connected controllable switching devices connected across a dc power source, each of said controllable switching devices including antiparallel diode, and each of said controllable switching devices further including a capacitance in parallel therewith;a first junction between a first pair of said controllable switching devices;a second junction between a second pair of said controllable devices;a transformer with primary and secondary windings;a pair of resonant inductors, each of said resonant inductors connected in series with a series capacitor, a first of said pair of resonant inductors and its series capacitor connected between said first junction and a non-common terminal of said first winding of said coupled inductor; a second of said pair of resonant inductors and its series capacitor connected between said second junction and a non-common terminal of said second winding of said coupled inductor;said primary winding of said transformer connected between the common terminal of said first and second windings of said coupled inductor and a terminal of said dc power source;said secondary winding of said transformer connected across a load;control means which periodically opens and closes said controllable switching devices to maintain a regulated ac voltage across said load; said control means providing a dead time in each of said pairs of said controllable switching devices between the opening of one said controllable switching device and the closing of the other said controllable switching device, said switching means further providing a delay time between the moment a switch in one of said pairs of said controllable switching devices and a switch in the other said pair of said controllable switches is closed.