An electronics circuit, comprising: a master controller; and a plurality of modules; wherein the master controller comprises: a timing signal generator arranged to generate a timing signal; and a data signal generator arranged to generate a data signal; wherein the master controller is arranged to generate a combined signal based on both the timing signal and the data signal; and wherein the master controller is arranged to broadcast the combined signal to the plurality of modules. By broadcasting the timing signal to the modules along with the data signal, the available bandwidth is effectively utilised without requiring a large number of separate signal paths to each module and without time multiplexing the signals. Thus accurate time synchronisation can be achieved such that the system can operate effectively at a high switching frequency. As the switches on the modules are not directly controlled by the master controller, the system provides a decentralised architecture in which processing of the received signals can be done locally on each module.

A method for transfer of power between medium voltage, MV, feeders via a MV direct current, MVDC, link in a power distribution network is presented. The method is performed in a controller in the power distribution network and includes setting an iteration step value for each of a set of power reference quantities of the MVDC link, and setting an initial value of each of the set of power reference quantities, iteratively changing values of each of the set of power reference quantities, and selecting one changed value of the set of power reference quantities by: changing a present value of each of the set of power reference quantities, one at a time, with the set iteration step value, respectively, into a new value, and measuring a total active power at a substation of the power distribution network for each of the new value, one at a time, and selecting the new value of the one of the set of power reference quantities that provides the lowest measured total active power at the substation, wherein a next iteration is performed with the selected new value as present value for the one of the set of power reference quantities and with the present value for the other of the set of power reference quantities. A controller for transfer of power between MV feeders via a MVDC link in a power distribution network is also presented.

Disclosed is a device for controlling a terminal connected in a multi-terminal high-voltage direct current transmission facility, the terminal being able to provide or draw power on the DC part of the facility comprised between an upper power limit and a lower power limit, the device further comprising at least one regulation circuit configured to vary the power provided or drawn by the terminal on the DC part of the facility, as a function of a voltage variation on the DC part of the facility, the device further comprising a limitation circuit configured to limit the variation of the power provided or drawn by the terminal, for a given voltage variation, when the power difference between the power provided or drawn by said terminal and the upper power limit or the lower power limit becomes smaller than a determined value.

Technologies for providing secure emergency power control of a high voltage direct current transmission (HVDC) system include a controller. The controller includes circuitry configured to receive status data indicative of a present physical status of a power system. The circuitry is also configured to obtain an emergency power control command triggered by a remote source. The emergency power control command is to be executed by an HVDC transmission system of the power system. Further, the circuitry is configured to determine, as a function of the status data, whether the emergency power control command is consistent with the present physical status of the power system and block, in response to a determination that the emergency power control command is not consistent with the present physical status of the power system, execution of the emergency power control command by the HVDC transmission system.

A method for calculating the steady-state fault current of a modular multilevel converter (MMC) comprises calculating the dc-side critical resistance values R.sub.A/B, R.sub.B/C and R.sub.C/D of the MMC based on the bridge arm inductance coefficient k and the ac-side reactance X.sub.ac of the MMC; Then, determining the operating modes of the MMC based on R.sub.A/B, R.sub.B/C and R.sub.C/D, and calculating the steady-state dc fault current and the conduction overlap angle respectively under various operating modes without considering the ac-side resistance based on the parameters k, U.sub.s, R.sub.dc and the dc-side critical resistance values R.sub.A/B, R.sub.B/C and R.sub.C/D; After that the steady-state AC fault current amplitude and phase angle for each operating mode without considering the AC side resistance are calculated based on the DC current and conduction overlap angle for each operating mode, respectively. Finally, the steady-state AC fault current amplitude and phase angle are calculated for various operating modes considering the AC side resistance.

An electric power supply apparatus for a user device, in particular for steel industry applications, that includes means for connection to an electricity grid for supplying a mains voltage and a mains current, and at least one electric line for connecting the electricity grid to the user device, wherein the electric line includes one or more electric apparatuses located between the electricity grid and the user device.

Provided is a system for an insulated-gate bipolar transistor (IGBT) rectifier for charging ultra-capacitors. The system may include a power converter, which may receive power from a power source. A direct current (DC) bus may be connected to the power converter and may receive power from the power converter. At least one IGBT may be connected to the DC bus and may receive power from the DC bus. An array of ultra-capacitors may be connected to the at least one IGBT. At least one controller may control the at least one IGBT to charge the array of ultra-capacitors. A method and computer program product are also disclosed.

A sub-module is disclosed. A sub-module according to an embodiment of the present invention comprises a short-circuiting control part. The short-circuiting control part comprises a movable member slidably coupled to a frame on which capacitor assemblies are seated. A variable connector is coupled to the movable member. Moreover, a plurality of short-circuiting blocks are arranged on the frame while being spaced away from each other. When the movable member has slid, the variable connector comes into contact with one or more short-circuiting blocks adjacent to each other to be electrically conductive. The short-circuiting blocks are connected to the capacitor assemblies, respectively, to be electrically conductive. Therefore, a plurality of capacitor elements can be short-circuited simultaneously only by moving the movable member.

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.

A power conversion device that performs power conversion between a DC circuit and an AC circuit includes a power conversion circuit including a plurality of sub-modules, a failure detection device that detects an internal failure of the power conversion circuit, and a control device that generates an operation command controlling operation of each of the plurality of sub-modules. The control device acquires a voltage value of a capacitor included in each sub-module, calculates a deviation between a variance value indicating a variation in the voltage value of the capacitor included in the sub-module in a reference period and a reference variance value in the sub-module for each of a plurality of sub-modules, determines a failure section of an internal failure based on the deviation in each sub-module when the internal failure is detected, and outputs an operation command based on a determination result to each sub-module.