A converter system for converting a three-phase or a single-phase AC voltage into a DC voltage, wherein the converter system includes three converter branches, each converter branch including a first input and a second input to be supplied with a single-phase AC voltage and a first output and a second output providing a DC voltage; wherein each converter branch includes an AC-to-DC stage and a DC-to-DC stage, which are connected between the first and second input and the first and second output; wherein the converter system is configured for interconnecting the first input of each converter branch with a phase of a three-phase grid and for interconnecting the first inputs of the converter branches with a phase of a single-phase grid; wherein the converter system is configured for interconnecting the second inputs, which are interconnected with each other, of the converter branches with a neutral point of the three-phase grid or the single-phase grid; and wherein the converter system includes one or more controllers adapted for controlling the converter branches independently from each other.

A converter system for converting a three-phase or a single-phase AC voltage into a DC voltage, wherein the converter system includes three converter branches, each converter branch including a first input and a second input to be supplied with a single-phase AC voltage and a first output and a second output providing a DC voltage; wherein each converter branch includes an AC-to-DC stage and a DC-to-DC stage, which are connected between the first and second input and the first and second output; wherein the converter system is configured for interconnecting the first input of each converter branch with a phase of a three-phase grid and for interconnecting the first inputs of the converter branches with a phase of a single-phase grid; wherein the converter system is configured for interconnecting the second inputs, which are interconnected with each other, of the converter branches with a neutral point of the three-phase grid or the single-phase grid; and wherein the converter system includes one or more controllers adapted for controlling the converter branches independently from each other.

Electrical systems for connecting rotary electric machines to dc networks operating at different voltages V and W where V>W along with gas turbine engine arrangements incorporating such systems.

Electrical systems for connecting rotary electric machines to dc networks operating at different voltages V and W where V>W are provided, along with gas turbine engine arrangements incorporating such systems.

Efficient measures to improve electrical performance in a mobile side output circuitry of a wireless power transmission system are provided. The mobile side circuitry of the wireless power transmission system has a mobile side transformer stage comprising at least one primary side winding and a plurality of secondary side windings. To the plurality of secondary side windings there are connected a plurality of mobile side AC/DC converters. According to a first alternative of the present invention output terminal pairs of the plurality of mobile side AC/DC converters are connected in series. According to a second alternative of the present invention output terminal pairs of the plurality of mobile side AC/DC converters are connected in parallel. According to a third alternative of the present invention mobile side AC/DC converters are grouped into a plurality of mobile side output groups such that output terminal pairs within each mobile side output group are connected in series and output terminal pairs of different mobile side output groups are connected in parallel.

An energy storage device for a power system is provided. The energy storage device is electrically connected with a high voltage DC transmission grid. The energy storage device includes at least one energy storage element, at least one bidirectional inverter module, at least one medium frequency transformer and at least one bidirectional AC/DC conversion module. A DC terminal of each bidirectional inverter module is electrically connected with the corresponding energy storage element. A first transmission terminal of each medium frequency transformer is electrically connected with an AC terminal of the corresponding bidirectional inverter module. An AC terminal of each bidirectional AC/DC conversion module is electrically connected with a second transmission terminal of the corresponding medium frequency transformer. A DC terminal of each bidirectional AC/DC conversion module is electrically connected with the high voltage DC transmission grid.

Provided is a system for seamless power conversion in DC power distribution, the system including power conversion devices connected in parallel, and performing conversion from a AC voltage to a DC voltage between an AC power distribution network and a DC power distribution network, wherein a master power conversion device among the power conversion devices converts the AC voltage supplied from the AC power distribution network into the DC voltage including an AC voltage at a preset level, and supplies the DC voltage to a DC power distribution line of the DC power distribution network, and the remaining power conversion devices that are slave power conversion devices detect the DC voltage at the DC power distribution line in real time, and when the AC voltage is not sensed from the detected DC voltage, one of the slave power conversion devices is converted into a master power conversion device.

Provided is a system for seamless power conversion in DC power distribution, the system including power conversion devices connected in parallel, and performing conversion from a AC voltage to a DC voltage between an AC power distribution network and a DC power distribution network, wherein a master power conversion device among the power conversion devices converts the AC voltage supplied from the AC power distribution network into the DC voltage including an AC voltage at a preset level, and supplies the DC voltage to a DC power distribution line of the DC power distribution network, and the remaining power conversion devices that are slave power conversion devices detect the DC voltage at the DC power distribution line in real time, and when the AC voltage is not sensed from the detected DC voltage, one of the slave power conversion devices is converted into a master power conversion device.

It is therefore an objective of the invention to provide an apparatus for conversion between AC power and DC power. The apparatus includes a first power conversion circuit having a first AC side and a first DC side, at least one second power conversion circuit each having a second AC side and a second DC side; and at least one choke having a first terminal, a second terminal and at least one third terminal, wherein the first terminal is arranged to be electrically coupled to a phase of the AC power, and the second terminal and the at least one third terminal are electrically coupled to respective same phases of the first AC side of the first power conversion circuit and the second AC side of the at least one second power conversion circuit. Moreover, the choke includes a first common-mode choke and a first differential-mode choke, wherein: the first common-mode choke and the first differential-mode choke are electrically coupled in series via a first group of coil ends of the first common-mode choke and a first group of coil ends of the first differential-mode choke, and a second group of coil ends of one of the first common-mode choke and the first differential-mode choke are electrically coupled to the first terminal of the choke, and a second group of coil ends of the other are respectively electrically coupled to the second terminal and the at least one third terminal of the choke. The first common-mode choke can help provide high inductance to the high-frequency components of the common-mode current, which flows from the AC power source, since the impedance of the common-mode choke and the differential-mode choke depends on frequency on the same scale as inductance. The advantages of using the common-mode choke is that it provides twice the inductance of separate inductor design due to the coupling effect. Therefore it filters the common-mode current more effectively or the inductance size can be reduced for a given current ripple requirement.

A power converter includes a plurality of power conversion units connected to one another in parallel, each including an AC/DC converter (rectifier) that converts AC power from an AC input power supply (commercial power supply) into DC power, a DC/DC converter (DC power converter) that converts the DC power from the AC/DC converter, and a current detector that detects charge current flowing from the DC/DC converter as well as discharge current flowing to the DC/DC converter. The power converter further includes a battery (electrical storage unit) that is charged by a subset of DC/DC converters among the DC/DC converters of the plurality of power conversion units, as well as a CPU (controller) that controls the DC/DC converters of the plurality of power conversion units.