Using reverse blocking IGBTs in power converters for adjustable speed drives

A new semiconductor power device badly needed in certain power converter topologies, the reverse blocking IGBT, has been realized by adding minor changes to the structure of a standard IGBT, which makes it capable of withstanding reverse voltage, but the switching behavior of its intrinsic diode during reverse recovery is not so good as it is in a discrete IGBT and series diode implementation. This paper analyzes the use of this device in three power converter topologies that may benefit from it: the matrix converter, the two-stage direct power converter (DPC) and the three-level voltage source rectifier. A commutation method to override the poor reverse recovery characteristic of the RB-IGBT intrinsec diode in a two-stage DPC is proposed. A loss analysis shows that by using RB-IRBTs, the efficiency of the two-stage DPC becomes similar to a two-level voltage source converter, which is known as the most efficient sine wave-in topology.