Abstract: There is provided a method, and a controller, for controlling a number of submodules in a valve of a power converter, the method including: determining, by a controller, a first switching time for a first submodule of the submodules; determining, by the controller, a second switching time for a second submodule of the submodules, wherein the first switching time differs from the second switching time by a time difference; wherein the time difference is based on a property of resonance in the power converter, wherein the resonance in the power converter is that caused by switching at least one submodule of the submodules in the valve; and providing, by the controller, one or more switching commands to the valve to cause the first submodule to switch at the first switching time and the second submodule to switch at the second switching time.

Abstract: There is provided a method, and a controller, for controlling a number of submodules in a valve of a power electronics device. The method includes determining, by the controller, a time period in which selected submodules of the submodules are to be switched in order to control an output voltage of the valve; determining, by the controller, for each of the selected submodules, a respective switching time, within the time period, based on a voltage demand for the time period and a voltage of each of the selected submodules, wherein at least one of the respective switching times is different to another of the respective switching times; generating, by the controller, a respective switching command for each of the selected submodules; and providing, by the controller, the respective switching commands to the valve, whereby to control the selected submodules to switch at the respective switching times within the time period.

Abstract: An apparatus for operating a direct current circuit breaker, DCCB, including at least one memory; and at least one processor coupled with the at least one memory and configured to cause the apparatus to: receive an indication corresponding to one of a number of modes for operating the DCCB, wherein the modes for operating the DCCB include a testing mode and a fault-current breaking mode; generate a control signal for activating a current commutation branch of the DCCB, wherein the control signal includes a first positive gate voltage in response to the indication corresponding to the testing mode, and wherein the control signal includes a second positive gate voltage in response to the indication corresponding to the fault-current breaking mode; and wherein the first positive gate voltage is lower than the second positive gate voltage.

Abstract: A DC energy storage system may include first and second DC terminals for connection to a DC link, a DC energy storage converter including a number of modules connected in series between the first and second DC terminals, 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 being combinable to selectively provide a voltage source, and at least one circuit interruption device connected in series with the DC energy storage converter between the first and second DC terminals, the or each circuit interruption device operable to electrically separate the DC energy storage converter from the DC link.

Abstract: An electrical assembly includes a voltage source converter including at least one energy storage device, an energy storage system electrically coupled to the voltage source converter, the energy storage system controllable to release and absorb energy, and a controller programmed to selectively trigger a control of the energy storage system to release energy or absorb energy responsive to a measurement of stored energy in the voltage source converter.

Abstract: A DC energy storage system may include first and second DC terminals for connection to a DC link, a DC energy storage converter including a number of modules connected in series between the first and second DC terminals, each module including at least one switching element and at least one battery, the or each switching element and the or each battery in each module being combinable to selectively provide a voltage source, and at least one fire-resistant protective barrier arranged to separate the modules into converter sections, each converter section including at least one module of the number of modules.

Abstract: A direct current circuit breaker system operable to interrupt a direct current flowing through a direct current line. The direct current line has a first potential with respect to ground potential and is elevated above ground level providing an electrically insulated gap, the direct current circuit breaker system including: one or more electrical sub-systems elevated above ground level and configured to operate at the first potential; a first electrical generator elevated above ground level and configured to operate at the first potential, wherein the first electrical generator is arranged to convert received energy into electrical energy at the first potential, the electrical energy for powering the electrical sub-systems; and an electric motor for generating the received energy, wherein the electric motor is configured to operate at ground potential and is operably coupled to the first electrical generator via a physical connection, wherein the physical connection is electrically insulated.

Abstract: A system and a method for managing a fault on a transmission line. The system includes an electrical branch, a diode arrangement and a controller. The electrical branch includes an inductor and a circuit breaker connected in series between a first terminal and a second terminal. The circuit breaker is configured to connect or disconnect the first terminal and the second terminal. The diode arrangement includes at least one diode, wherein a first end of the diode arrangement is connected to the electrical branch, and a second end of the diode arrangement is connected to a third terminal. The controller is configured to receive an indication signal, wherein the indication signal is indicative of a forward current in the diode arrangement. The controller is further configured to, in response to receiving the indication signal, issue a command to the circuit breaker to disconnect the first terminal and the second terminal.

Abstract: There is provided a switching valve for a voltage source converter, the switching valve comprising a plurality of modules, each module including at least one switching element and at least one energy storage device, each switching element and each energy storage device in each module arranged to be combinable to selectively provide a voltage source, the switching valve including a regulator programmed to selectively control the switching of the switching elements to select one or more of the modules to contribute a respective voltage to a switching valve voltage, wherein the regulator is programmed to selectively regulate an energy stored in each energy storage device by controlling the switching of the switching elements to regulate a voltage of each energy storage device towards a target voltage, and the regulator is programmed to vary the target voltage of each energy storage device as a function of a number of healthy modules.

Abstract: An electrical assembly includes a number of modules, each module including at least one module switching element and at least one energy storage device, each module switching element and each energy storage device in each module arranged to be combinable to provide a voltage source, each module including a discharge circuit with a discharge switching element and a discharge resistor, each discharge switching element switchable to switch the corresponding discharge resistor into and out of the corresponding module, wherein the electrical assembly includes a controller configured to control the discharge switching elements to modulate the switching of each discharge resistor into and out of the corresponding module in a voltage balancing mode when the modules are in a blocked state so that each module emulates a resistive load profile to balance a distribution of voltages between the modules, wherein the resistive load profile includes at least one positive resistive slope.

Abstract: In the field of chain-link modules for voltage source converters, there is a need for an improved chain-link module. Embodiments of the disclosure include a chain-link module, for connection in series with other chain-link modules to form a chain-link converter selectively operable to provide a stepped variable voltage source within a voltage source converter. The module can include a first pair of series-connected switching elements which are separated by a first connection terminal and are connected in parallel with first and second series-connected energy storage devices. The chain-link module can also include a second pair of series-connected switching elements that are separated by a second connection terminal, and which are connected in parallel with one or other of the first and second energy storage devices.

Abstract: A DC energy storage system may include first and second DC terminals for connection to a DC link, a DC energy storage converter including a number of modules connected in series between the first and second DC terminals, 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 being combinable to selectively provide a voltage source, and at least one circuit interruption device connected in series with the DC energy storage converter between the first and second DC terminals, the or each circuit interruption device operable to electrically separate the DC energy storage converter from the DC link.

Abstract: A DC energy storage system may include first and second DC terminals for connection to a DC link, a DC energy storage converter including a number of modules connected in series between the first and second DC terminals, each module including at least one switching element and at least one battery, the or each switching element and the or each battery in each module being combinable to selectively provide a voltage source, and at least one fire-resistant protective barrier arranged to separate the modules into converter sections, each converter section including at least one module of the number of modules.

Abstract: There is provided a switching valve for a voltage source converter, the switching valve comprising a plurality of modules, each module including at least one switching element and at least one energy storage device, each switching element and each energy storage device in each module arranged to be combinable to selectively provide a voltage source, the switching valve including a regulator programmed to selectively control the switching of the switching elements to select one or more of the modules to contribute a respective voltage to a switching valve voltage, wherein the regulator is programmed to selectively regulate an energy stored in each energy storage device by controlling the switching of the switching elements to regulate a voltage of each energy storage device towards a target voltage, and the regulator is programmed to vary the target voltage of each energy storage device as a function of a number of healthy modules.

Abstract: In the field of chain-link modules for voltage source converters, there is a need for an improved chain-link module. Embodiments of the disclosure include a chain-link module, for connection in series with other chain-link modules to form a chain-link converter selectively operable to provide a stepped variable voltage source within a voltage source converter. The module can include a first pair of series-connected switching elements which are separated by a first connection terminal and are connected in parallel with first and second series-connected energy storage devices. The chain-link module can also include a second pair of series-connected switching elements that are separated by a second connection terminal, and which are connected in parallel with one or other of the first and second energy storage devices.

Abstract: An electrical assembly includes a number of modules, each module including at least one module switching element and at least one energy storage device, each module switching element and each energy storage device in each module arranged to be combinable to provide a voltage source, each module including a discharge circuit with a discharge switching element and a discharge resistor, each discharge switching element switchable to switch the corresponding discharge resistor into and out of the corresponding module, wherein the electrical assembly includes a controller configured to control the discharge switching elements to modulate the switching of each discharge resistor into and out of the corresponding module in a voltage balancing mode when the modules are in a blocked state so that each module emulates a resistive load profile to balance a distribution of voltages between the modules, wherein the resistive load profile includes at least one positive resistive slope.

Abstract: This application relates to methods and apparatus for fault protection in a DC power transmission network or grid that aid in determining the location of a fault in the network. The method involves, in the event of a fault, controlling at least one current limiting element of the network so as to limit a fault current flowing to below a first current level which is within the expected current operating range of the network in normal operation, i.e. a safe level. The fault current is then controlled to maintain a non-zero level of fault current flow and the characteristics of the fault current flow at different parts of the network are determined by fault current detection modules. The location of the fault is then determined based on the determined characteristics.

Abstract: In one general aspect, a method is described. The method includes generating a positional relationship between one or more support structures having at least one motion capture mark and at least one virtual structure corresponding to geometry of an object to be tracked and positioning the support structures on the object to be tracked. The support structures has sufficient rigidity that, if there are multiple marks, the marks on each support structure maintain substantially fixed distances from each other in response to movement by the object. The method also includes determining an effective quantity of ray traces between one or more camera views and one or more marks on the support structures, and estimating an orientation of the virtual structure by aligning the determined effective quantity of ray traces with a known configuration of marks on the support structures.

Abstract: This application relates to methods and apparatus for fault protection in a DC power transmission network or grid that aid in determining the location of a fault in the network. The method involves, in the event of a fault, controlling at least one current limiting element of the network so as to limit a fault current flowing to below a first current level which is within the expected current operating range of the network in normal operation, i.e. a safe level. The fault current is then controlled to maintain a non-zero level of fault current flow and the characteristics of the fault current flow at different parts of the network are determined by fault current detection modules. The location of the fault is then determined based on the determined characteristics.

Abstract: In one general aspect, a method is described. The method includes generating a positional relationship between one or more support structures having at least one motion capture mark and at least one virtual structure corresponding to geometry of an object to be tracked and positioning the support structures on the object to be tracked. The support structures has sufficient rigidity that, if there are multiple marks, the marks on each support structure maintain substantially fixed distances from each other in response to movement by the object. The method also includes determining an effective quantity of ray traces between one or more camera views and one or more marks on the support structures, and estimating an orientation of the virtual structure by aligning the determined effective quantity of ray traces with a known configuration of marks on the support structures.