Patent ID: 6172550
Filing Date: 2001-01-09
Classification: H03K

Abstract:
A power conversion system comprising:a switching circuit having an input terminal for supplying power to said circuit and an output terminal coupled to a load which receives power from said circuit, said circuit comprising:cryogenically cooled first and second switching devices, each switching device comprising an intrinsic drain-to-source commutating diode capable of conveying an inductive current component from the load;a controller, which controls a deadtime period between switching of the first switching device and the second switching device, the controller providing a first control signal to turn-on the first switching device in a first time interval following turn-off of the second switching device, such that an inductive current component flows through the first switching device rather than through the intrinsic drain-to-source diode associated with the first switching device, said controller including a sensing circuit for sensing said inductive current component for generating said first control signal; anda refrigeration unit for cryogenically cooling at least said switching devices.