An ac-ac power converter system is provided for supplying power to an
electrical load. The ac-ac power converter system provides an output
voltage having variable amplitude and/or frequency. The ac-ac power
converter system includes a boost inductor for applying a discontinuous
current to an ac-ac power converter. The ac-ac power converter includes a
rectifier circuit comprising of a first set of gate controllable active
switches for converting an input ac power to a dc power and an inverter
circuit comprising of a second set of gate controllable active switches
for converting the dc power to an output ac power. In addition, the ac-ac
power converter system includes a switch for switching between a first
mode of operation and a second mode of operation. The first set of gate
controllable active switches is common between the inverter circuit and
the rectifier circuit and is operable at about 50 percent of duty cycle
in the first mode of operation while the inverter circuit is a half
bridge inverter circuit in the second mode of operation.