Apparatus and method for soft switching in a medium voltage to low voltage converter

摘要

A switching and control arrangement are provided along with a transformer arrangement such that semiconductor-based switches can be used in a medium DC voltage to AC inverter in a medium voltage to low voltage DC to DC converter. The switching arrangement on the secondary side of the transformer arrangement controls a current ramp up or down of switches on the primary side of the transformer that are used to convert DC to AC, thereby permitting for soft switching of those switches.

主权项

1. A medium voltage to low voltage DC to DC converter, comprising:
a DC to AC voltage inverter; an AC to DC voltage converter; and a hybrid transformer coupled between the DC to AC voltage inverter and the AC to DC voltage converter, the hybrid transformer including a first transformer having a primary coupled to the DC to AC voltage inverter and a second transformer and a third transformer each having a primary coupled to a secondary of the first transformer and each having a secondary; and a second switching arrangement associated with the AC to DC converter and coupled to the second transformer and the third transformer wherein the second switching arrangement alternately blocks current in the secondary of the second transformer and the secondary of the third transformer to provide soft switching of one or more switches in the DC to AC voltage inverter, wherein when the second switching arrangement blocks current in the secondary of the third transformer the secondary of the second transformer is conducting current and the primary of the third transformer appears as an inductance reflecting back a current to the primary of the first transformer, and wherein when the second switching arrangement blocks current in the secondary of the second transformer the secondary of the third transformer is conducting current and the primary of the second transformer appears as an inductance reflecting back a current to the primary of the first transformer.