Inductively commutated thyristor inverter

Claim 1

A power converter apparatus comprising; a bridge circuit including a thyristor bridge having thyristors, and feedback diodes connected in inverse parallel relationship to said thyristors for conducting current in reverse direction to that of said thyristors; a solid-state switching device inserted in series in at least one of positive and negative lines interconnecting a DC power supply and DC input terminals of said bridge circuit for cutting off a current flowing from aid DC power supply to said bridge circuit when reverse-biasing said thyristors in said bridge circuit, a series-connected circuit of an inductance element and an auxiliary switching device connected between said positive and negative DC lines through said solid-state switching device, a reverse-conducting element for passing a current in reverse direction to that of said solid-state switching device, and control means for creating an interval of time in which the solid-state switching device and the auxiliary solid-state switching device are rendered conductive simultaneously, the arrangement being that a magnetic energy will be stored in said inductance element during said interval of time, and the magnetic energy will be discharged to reverse-bias the thyristors.