Patent ID: 7582939

Claim:
A voltage source converter comprising: at least one semiconductor diode cell including semiconductor diode having a) a first region of a given conduction type, b) a second region having an opposite conduction type relative to the first region, c) a pn junction formed between the first region and the second region, d) a first electrode in direct electrical contact with the first region, e) a second electrode in direct electrical contact with the second region, and f) a gate electrode isolated from at least one of said regions by an insulation layer and adapted to alter a concentration of a majority charge carrier in said first region when a voltage is applied between said first electrode and said gate electrode, to switch said semiconductor diode between a first state and a second state, said second state having a greater forward resistance and a smaller storage charge in comparison with said first state, wherein said pn junction is adapted to provide blocking in both said first and second states and having at least one given breakdown voltage characteristic in said first and second states; and at least one power turn-off semiconductor cell having at least one power turn-off semiconductor selected from the group consisting of MOSFET, IGBT, bipolar transistor, GTO, and IGCT, wherein said rower turn-off semiconductor cell and said semiconductor diode cell are adapted to be driven by a common drive circuit, and wherein a gate of the power turn-off semiconductor is connected to said gate electrode to switch the semiconductor diode between said first and second states.