Abstract: There is provided a sensor system for use in a high voltage direct current network. The sensor system comprises a plurality of sensor devices, each sensor device configured to obtain a respective sensor measurement, wherein the plurality of sensor devices are configured to generate a serial data unit for transmission to a recipient system, the serial data unit configured to include the plurality of sensor measurements (S1, S2, Sn), the serial data unit further configured to include a plurality of validity indicators (FCS1, FCS2, FCSn), each validity indicator (FCS1, FCS2, FCSn) configured to provide an individual validity status of a respective one of the plurality of sensor measurements (S1, S2, Sn).

Abstract: A voltage source converter includes first and second DC terminals which have at least one converter limb extending therebetween. Each limb portion includes a chain-link converter that extends between an associated AC terminal and a corresponding one of the first or the second DC terminal. Each chain-link converter also includes a chain-link converter controller which is programmed to control a series of connected chain-link modules. The voltage source converter additionally includes a voltage source converter controller which is arranged in operative communication with each chain-link converter controller to coordinate operation of the chain-link converters. Each chain-link converter controller is further programmed to reconstruct from a received modulation index demand the chain-link converter voltage reference, which the chain-link converter it is controlling is required to produce, by multiplying the received modulation index demand by a total voltage sum established at a first time instant.

Abstract: There is provided a switching valve for a voltage source converter, the switching valve including a number of modules, each module including at least one switching element and at least one energy storage device, the or each switching element and the or each energy storage device in each module arranged to be combinable to selectively provide a voltage source, the switching valve including a controller programmed to selectively control the switching of the switching elements to select one or more of the modules to contribute a or a respective voltage to a switching valve voltage.

Abstract: There is provided an electrical assembly comprising a converter (20) for connection to an electrical network (40), the converter (20) comprising at least one module (44) including at least one switching element (46) and at least one energy storage device (48), the or each switching element (46) and the or each energy storage device (48) in the or each module (44) arranged to be combinable to selectively provide a voltage source, the electrical assembly including a controller (54) configured to selectively control the switching of the or each switching element (46) in the or each module (44), wherein the electrical assembly includes a sensor (56a) configured for measuring a current of the electrical network (40), wherein the controller (54) and sensor (56a) are configured to operate in coordination to carry out a characterisation of an electrical parameter of the electrical network (40) so that, in use: the controller (54) selectively controls the switching of the or each switching element (46) in the or ea

Abstract: A power transmission network includes converters interconnected via electrical elements, at least one power flow router, and a controller. Each power flow router being operatively connected to the electrical elements, each power flow router configured to selectively control current flow in the electrical elements so as to direct power between two or more of the plurality of converters.

Abstract: A switching valve includes series-connected switching elements and auxiliary circuits. Each auxiliary circuit is connected in parallel with a respective one of the series-connected switching elements. Each auxiliary circuit includes a respective auxiliary capacitor. The method includes carrying out a compensation procedure. The compensation procedure includes: initiating a turn-off event by sending a respective turn-off control signal to each switching element; measuring a respective capacitor voltage value of each auxiliary capacitor after the turn-off event; comparing the measured capacitor voltage values; and using the comparison between the measured capacitor voltages as a reference to adjust the time of sending a or a respective turn-off control signal to at least one of the switching elements so as to reduce a or a respective time difference between the turn-off times of the switching elements at the next turn-off event.

Abstract: A power transmission network includes converters interconnected via electrical elements, at least one power flow router, and a controller. Each power flow router being operatively connected to the electrical elements, each power flow router configured to selectively control current flow in the electrical elements so as to direct power between two or more of the plurality of converters.

Abstract: There is provided a sensor system for use in a high voltage direct current network. The sensor system comprises a plurality of sensor devices, each sensor device configured to obtain a respective sensor measurement, wherein the plurality of sensor devices are configured to generate a serial data unit for transmission to a recipient system, the serial data unit configured to include the plurality of sensor measurements (S1, S2, Sn), the serial data unit further configured to include a plurality of validity indicators (FCS1, FCS2, FCSn), each validity indicator (FCS1, FCS2, FCSn) configured to provide an individual validity status of a respective one of the plurality of sensor measurements (S1, S2, Sn).

Abstract: A far-end power converter within a DC transmission network that includes a near-end power converter and at least one far-end power converter interconnected by portions of transmission medium. A method includes: establishing a linear time-invariant model of the transmission medium; determining a response characteristic of the time-invariant model; measuring an output operating property of the transmission medium at the near-end power converter; identifying one far-end power converter as being of interest; deriving a corresponding input operating property of the transmission medium at the far-end power converter of interest by applying an inverse of the response characteristic of the time-invariant model to the measured output operating property of the transmission medium at the near-end power converter; and comparing the derived input operating property with a fault characteristic to determine whether there is a fault on the far-end power converter of interest.

Abstract: A voltage source converter includes DC terminals for connection to a DC network, a plurality of converter limbs between the DC terminals, and a controller. Each converter limb includes first and second limb portions separated by a respective AC terminal, the AC terminal of each converter limb connecting to a multi-phase AC network. Each limb portion extends between a corresponding DC terminal and AC terminal. Each limb portion including a valve having switching element(s) and energy storage device(s), the switching element being switchable to selectively insert the energy storage device into the limb portion and bypass the energy storage device to control a voltage across that valve. The controller is programmed to control the switching of valves to form a current circulation path including the limb portions corresponding to the selected valves, the AC phases connected to the limb portions corresponding to the selected valves, and the DC network.

Abstract: A voltage source converter including a plurality of terminals, a plurality of switching elements, a plurality of energy storage devices connected between the plurality of terminals, and a controller. Each energy storage device stores and releases energy to provide a voltage, and the plurality of switching elements are arranged to be switchable to control flow of current through each energy storage device. The controller is programmed to operate in an energy regulation mode to regulate energy.

Abstract: A method of controlling a voltage source converter including a converter limb corresponding to a respective phase of the converter, each converter limb extending between first and second DC terminals and including first and second limb portions separated by an AC terminal and each limb portion including a chain-link converter which is operable to provide a stepped variable voltage source, includes the steps of obtaining a AC current demand phase waveform and a DC current demand for each corresponding converter limb is configured to track, and carrying out mathematical optimization to determine an optimal limb portion current for each limb portion must contribute to track the corresponding required AC current demand phase waveform and the required DC current demand while minimising current conduction losses within each limb portion and additionally managing the energy stored by each chain-link converter.