Various embodiments of the teachings herein include a grid influencing system for a power supply grid comprising: a current-conducting grid influencing component; and a vacuum circuit breaker including a vacuum circuit breaker tube containing an at least partly integrated pre-arcing device for actively generating an arc between two contacts.

This invention relates to a surface finish manufacturing system and process and more particularly, but not exclusively, to a contrast surface finish manufacturing system and process for producing boards with a wood texture finish. The surface finish manufacturing system comprises a top layer and a bottom layer where part of the top layer is removed to expose part of the bottom layer.

A method can be used to control a flexible interconnection device that includes a number of converters. The method includes receiving a plurality of voltage signals indicating respective voltages of a plurality of load branches and a plurality of current signals indicating respective currents of the plurality of load branches, determining reference active power values for each of the plurality of converters based on the plurality of voltage signals and a plurality of reference voltage signals, determining reference reactive power values for each of the plurality of converters based on the plurality of voltage signals, the plurality of reference voltage signals and the plurality of current signals, and controlling the plurality of converters based on the determined reference active power values and the determined reference reactive power values.

Provided are hybrid passive power filter and a three-phase power system. The hybrid passive power filter includes: a series passive harmonic isolation unit, a parallel passive filtering unit, and a harmonic load; the series passive harmonic isolation unit has an input terminal electrically connected to a power grid and an output terminal electrically connected to a first terminal of the harmonic load, and the series passive harmonic isolation unit is configured to isolate harmonics; and the parallel passive filtering unit has an input terminal electrically connected to the output terminal of the series passive harmonic isolation unit and an output terminal electrically connected to a second terminal of the harmonic load, and the parallel passive filtering unit is configured to filter out harmonics.

A method which is suitable for a system having a frequency converter and a generator, both of which are connected to a power grid, includes obtaining sub-synchronous components of the grid voltage and determining damping current set points according to the sub-synchronous components to compensate for sub-synchronous resonances of the grid. Damping current set points are determined by receiving the sub-synchronous components of the grid voltage and returning damping current set points as outputs. A variable damping gain is adjusted according to the sub-synchronous frequency of the grid, such that the required compensation level can be adapted to the frequency converter for damping sub-synchronous resonance of the grid.

A system for powering a datacenter campus including a main direct current (DC) superconductor cable configured to receive direct current DC electrical power from an alternating current (AC) power grid through a AC-DC converter, a DC-DC hub connected to the main superconductor cable, and a plurality of secondary DC superconductor cables, wherein each secondary DC superconductor cable includes a first end electrically connected to the DC-DC hub and a second end electrically connected to server racks housed in a respective datacenter building of the datacenter campus.

A starting and stopping method for a static synchronous series compensator (SSSC) is provided. A starting process includes: first, connecting a converter (4) to a shunt transformer (2), and closing an incoming line switch (1) of the shunt transformer to charge the current converter until a direct-current voltage is stable; then, opening the incoming line switch of the shunt transformer, and connecting the converter to a series transformer (5) through a change-over switch (3); deblocking the converter, and controlling a current of a bypass switch (6) of the series transformer to approach zero; further, opening the bypass switch of the series transformer, and enabling the converter to enter a normal operation mode after a line is stable; and in stopping the SSSC, first, switching a control mode of the converter to make the current of the bypass switch approaches zero when closed the bypass switch, then controlling a current of the series transformer to be gradually reduced to zero to make the series transformer out of service, and then blocking the converter. By means of the method, an overvoltage and an overcurrent of a converter when a series transformer is put into use and exits can be effectively suppressed, and current oscillation of an line and impact on the series transformer can be reduced, thereby achieving stable starting and stopping of an SSSC.

A device is for reactive power compensation in a high-voltage network having a phase conductor. The device has a first high-voltage terminal, which is configured to be connected to the phase conductor. For each first high-voltage terminal, a first and a second core section, which are part of a magnetic circuit, a first high-voltage winding, which encloses the first core section, and a second high-voltage winding are provided. Moreover, the device has a saturation switching branch, which saturates the core sections and has controllable power semiconductor switches. A control unit is used to control the power semiconductor switches. The first and the second high-voltage windings are connected by the high-voltage end to the associated first high-voltage terminal and on the low-voltage side can be connected to one or the saturation switching branch. To be able to be connected in series into the high-voltage network, a second high-voltage terminal is provided.

A method can be used to determine a fault location in a power transmission line that connects a first terminal with a second terminal. Parameters associated with travelling waves are detected from measurements carried out at the first and second terminals. The parameters include arrival times of first and second peaks of the travelling waves at the first and second terminals respectively, and rise times of the first peaks of corresponding travelling waves. A first half, a second half, or a mid-point of the power transmission line is identified as having a fault based on the parameters. The fault location can be estimated based on the arrival times of the first and second peaks of the travelling waves detected from measurements carried out at the first and second terminals, a velocity of propagation of the travelling wave in the power transmission line, and/or a length of the power transmission line.

A filter circuit for reducing feedback of a consumer on an energy supply is disclosed. This filter circuit includes a multipolar input, a line choke, and a multipolar output, wherein the input is configured to receive an AC voltage from the energy supply, wherein the output is configured to be connected to the consumer, wherein the line choke includes one coil for each pole of the input, and wherein the coils of the line choke are each connected between one pole of the input and one pole of the output and energy is transferred from the input to the output and/or vice versa. A resonant current suppression (RCS) group is connected in parallel to a coil of the line choke to transmit resonant currents arising at the line choke such that voltage increases generated by the resonant currents are reduced or suppressed by the at least one RCS circuit.