Abstract: The present disclosure relates to a voltage source converter (VSC) (300) comprising: a first MOSFET switching element (302) including a first body diode (306); a second MOSFET switching element (304) including a second body diode (308), the second MOSFET switching element (304) being connected in series with the first MOSFET switching element (302); a protection device (318) connected in parallel with the second MOSFET switching element (304); and a controller (312), wherein the controller (312) is configured, on detection of an overcurrent event, to: switch off the first MOSFET switching element (302); and switch off the second MOSFET switching element (304), thereby forcing current flowing in the VSC (300) following the overcurrent event to flow through the second body diode (308) rather than through conducting channels of the first and second MOSFET switching elements (302, 304).

Abstract: This application relates to a cell (1200) or sub-module for a voltage source converter (1201). The cell includes an energy storage apparatus (101; 101a, 101b) and a plurality of dual-switch semiconductor packages (201), each having first and second semiconductor switches (202, 203) connected in series. The cell is operable in an active state in which an energy storage apparatus (101; 101a, 101b) is electrically connected in series between cell terminals (102a, 102b) and a bypass state in the cell terminals (102a, 102b) are electrically connected via a path that bypasses the first energy storage apparatus.

Abstract: In the field of voltage source converters for high voltage direct current (HVDC) power transmission there is provided a protection arrangement for a switching device. The protection arrangement comprises a thyristor that has main current-carrying terminals which in use are connected in reverse parallel with a switching device to be protected, whereby during normal operation of the switching device a reverse voltage is applied to the thyristor. The protection arrangement also includes a trigger circuit that is operatively connected with a gate control terminal of the thyristor. The trigger circuit is configured to apply a voltage to the gate control terminal of the thyristor when the reverse voltage applied to the thyristor reaches a safety threshold voltage whereby the thyristor fails and presents an irreversible short-circuit across the main current-carrying terminals of the switching device.

Abstract: This application relates to a cell (1200) or sub-module for a voltage source converter (1201). The cell includes an energy storage apparatus (101; 101a, 101b) and a plurality of dual-switch semiconductor packages (201), each having first and second semiconductor switches (202, 203) connected in series. The cell is operable in an active state in which an energy storage apparatus (101; 101a, 101b) is electrically connected in series between cell terminals (102a, 102b) and a bypass state in the cell terminals (102a, 102b) are electrically connected via a path that bypasses the first energy storage apparatus.

Abstract: The present disclosure relates to a voltage source converter (VSC) (300) comprising: a first MOSFET switching element (302) including a first body diode (306); a second MOSFET switching element (304) including a second body diode (308), the second MOSFET switching element (304) being connected in series with the first MOSFET switching element (302); a protection device (318) connected in parallel with the second MOSFET switching element (304); and a controller (312), wherein the controller (312) is configured, on detection of an overcurrent event, to: switch off the first MOSFET switching element (302); and switch off the second MOSFET switching element (304), thereby forcing current flowing in the VSC (300) following the overcurrent event to flow through the second body diode (308) rather than through conducting channels of the first and second MOSFET switching elements (302, 304).

Abstract: There is disclosed a busbar assembly including a busbar having one or more conductor layers for electrical conduction, and an electrically conductive heat transfer line configured to convey a cooling fluid therethrough, where the heat transfer line is thermally and electrically coupled to a conductor layer of the busbar so that in use there is no voltage difference between the heat transfer line and the respective conductor layer of the busbar.