Patent ID: 8742295

Claim:
A method of reducing the blocking voltages across saturable reactors associated with a rectifier coupled to a transformer winding in an inverter rectifier output circuit during both turn-on and turn-off transitions of the rectifier, said method comprising: reducing at least a portion of a reverse recovery current associated with said rectifier by allowing blocking voltages to build across a first saturable reactor and a second saturable reactor, of said inverter rectifier output circuit during a transition phase of said rectifier; reducing said blocking voltages across said first saturable reactor and said second saturable reactor during a diode turn-off portion of said transition phase with a RC circuit, thereby suppressing a peak voltage associated with said rectifier; and reducing said blocking voltages across said first saturable reactor, said second, and said third saturable reactor during a diode turn-on portion of said transition phase with a third saturable reactor in series with a free-wheeling diode, wherein said first saturable reactor is connected to a first node at a first end of said transformer winding, wherein said second saturable reactor is connected to a second node at a second end of said transformer winding, and said third saturable reactor is connected to a center tap node at a center tap of said transformer winding, and wherein said third saturable reactor has an inductance less than one or more of said first saturable reactor and said second saturable reactor at least during switching.