Abstract: An electronic valve apparatus for a high voltage direct current, HVDC, power transmission system. The electronic valve apparatus includes a first device chain including a number of first devices connected in series between an input node and an output node. Each of the first devices has an asymmetric transfer function configured substantially to block current flow through the device in a first direction, and the first devices are connected such that they all block current flow in the same direction. The electronic valve apparatus also includes a second device chain including a number of second devices connected in series between the input node and the output node. Each of the second devices has an asymmetric transfer function configured substantially to block current flow through the device in a first direction, and the second devices are connected such that they all block current flow in the same direction.

Abstract: The present disclosure relates to an electronic valve apparatus for a high voltage direct current, HVDC, power transmission system. The electronic valve apparatus comprises a first device chain (301) including a plurality of first devices (302, 303) connected in series between an input node (330) and an output node (332) of the electronic valve apparatus (300, 400, 500). Each of the plurality of first devices (302, 303) has an asymmetric transfer function configured substantially to block current flow through the device in a first direction, and the plurality of first devices (302, 303) are connected such that they all block current flow in the same direction. The electronic valve apparatus also includes a second device chain (311) including a plurality of second devices (312, 313) connected in series between the input node (330) and the output node (332).

Abstract: In the field of high voltage direct current (HVDC) power transmission there is provided a power converter assembly (10) comprising a line-commutated power converter (12) that is configured to transfer power from a DC network (14) to a corresponding receiving AC network (16). The power converter assembly (10) also includes a control unit which is operatively associated with the line-commutated power converter (12) and is programmed, in response to the receiving AC network (16) exhibiting a reduced AC voltage (Va, Vb, Vc), to cause a reduction in the operating DC voltage (VDC) of the line-commutated power converter (12) by the DC network (14).

Abstract: In the field of high voltage direct current (HVDC) power transmission there is provided a power converter assembly (10) comprising a line-commutated power converter (12) that is configured to transfer power from a DC network (14) to a corresponding receiving AC network (16). The power converter assembly (10) also includes a control unit which is operatively associated with the line-commutated power converter (12) and is programmed, in response to the receiving AC network (16) exhibiting a reduced AC voltage (Va, Vb, Vc), to cause a reduction in the operating DC voltage (VDC) of the line-commutated power converter (12) by the DC network (14).

Abstract: In the field of high voltage direct current (HVDC) power transmission a line commutated converter (10) includes a plurality of converter limbs (12A, 12B, 12C) that extend between first and second DC terminals (16, 18). Each converter limb (12A, 12B, 2C) includes first and second limb portions (22, 24) that are separated by an AC terminal (26). The first limb portions (22) together define a first limb portion group (28) and the second limb portions (24) together define a second limb portion group (30). Each limb portion (22, 24) includes at least one switching element (32) in the form of a latching device (34). Each latching device (34) is configured to turn on and conduct current when it is forward biased and it receives a turn on signal, to naturally turn off and no longer conduct current when it is reverse biased and the current flowing through it falls to zero, and to actively turn off and prevent current from flowing therethrough when it receives a turn off signal.