The charging and/or discharging of a set of swappable battery modules in a battery system is carried out automatically using a set of charging and/or discharging control switches linked in a sequential charging and/or a discharging control chain. The charging and discharging of the set of battery modules can be done sequentially or in parallel, and is hardware-based with minimal software/firmware involvement. The system is scalable and automatically reconfigurable for use in an infrastructure and/or in an electric vehicle. The swappable battery modules may be positioned in the battery slots or butted together in the battery system.

A control switch incorporating a 1:2 demultiplexer is used to control timing for a concurrent switching, break-before-make and make-before-break power multiplexing, and is configurable to link a plurality of the control switches into a control chain to perform sequential charging, sequential discharging, parallel charging, parallel discharging, and concurrent sequential charging and discharging for a plurality of batteries coupled to the control chain in a power system.

A control switch incorporating a 1:2 demultiplexer is used to control timing for a concurrent switching, break-before-make and make-before-break power multiplexing, and is configurable to link a plurality of the control switches into a control chain to perform sequential charging, sequential discharging, parallel charging, parallel discharging, and concurrent sequential charging and discharging for a plurality of batteries coupled to the control chain in a power system.

The present application provides a conversion system and a control method, including N power converters and N controllers, and N controllers one-to-one corresponds to the N power converters. In addition to receiving a first side current and a second side voltage of a corresponding power converter, each of the N controllers can also receive a neighboring direct current voltage signal which only reflects second side voltages of other M power converters in the conversion system, and perform voltage control on the corresponding power converter according to the received signal. The present application adopts fully distributed control, and does not need to set up a centralized controller. When parts of controllers fail, the other controllers can continue to work, so the reliability is higher.

A power converter 10 includes: flying capacitor circuits 11 and 12 connected in series so as to be in parallel with a DC power supply; flying capacitor circuits 13 and 14 connected in series so as to be in parallel with the DC power supply; switching elements S1 and S2 connected in series between output terminals of the flying capacitor circuits 11 and 12; switching elements S3 and S4 connected in series between output terminals of the flying capacitor circuits 13 and 14; a first output end OUT1 provided at a midpoint between the switching elements S1 and S2; and a second output end OUT2 provided at a midpoint between the switching elements S3 and S4, wherein a node between the flying capacitor circuits 11 and 12 and a node between the flying capacitor circuits 13 and 14 are connected to a midpoint of a DC power supply voltage.

The present invention relates to a circuit for switching an AC voltage. It contains an input terminal able to be connected to an AC voltage source, an output terminal able to be connected to a load impedance, and a first series circuit. This series circuit comprises a diode and a circuit for storing electrical charges. The series circuit has a first end connection that is connected to the input terminal and a second end connection that is connected to the output terminal. The circuit for switching an AC voltage furthermore contains a DC voltage source, which is connected to an electrical connection between the diode and the input terminal or to an electrical connection between the diode and the output terminal and is designed to impress a DC current in the diode. The circuit for switching an AC voltage finally contains a first switch that is connected to an electrical connection between the diode and the circuit for storing electrical charges at one terminal. The first switch is designed to switch between a switching state in which a potential dependent on a reference potential is present at the electrical connection between the diode and the circuit for storing electrical charges, and a switching state in which an electrical floating potential is present in the electrical connection between the diode and the circuit for storing electrical charges.

A system comprises a first 3-phase rectifier having a positive DC lead and a negative DC lead and a second 3-phase rectifier having a positive DC lead and a negative DC lead. The system also includes a 4-phase, 3-level inverter connected to the first and second 3-phase rectifiers. A method comprises receiving variable frequency, 3-phase power from a first generator, receiving variable frequency, 3-phase power from a second generator, rectifying the variable frequency, 3-phase power from each of the first and second generators into DC power. And inverting the DC power into 4-phase, constant frequency power for powering a load.

A rectifier cell for rectifying an electrical AC voltage, which rectifier cell comprises a transistor series circuit having a first field effect transistor and a second field effect transistor. A first frequency-independent voltage divider connected in parallel with the transistor series circuit has a first node which is connected to the gate electrode of the first field effect transistor. A second frequency-independent voltage divider connected in parallel with the transistor series circuit has a second node which is connected to the gate electrode of the second field effect transistor. In this case, the first and the second node of the frequency-independent voltage dividers are additionally each connected to earth via a bias capacitor.

An electrical vehicle charging device includes a power converter for receiving an AC voltage from an AC grid or a DC voltage from a DC grid, a transformer having a primary side connected to an output side, a full wave rectifier having a first input and a secondary input and a positive output and a negative output, at least two output capacitors connected between respective end taps of end taps connected in series via a center tap and between the positive output and the negative output, whereby the end taps are for providing the DC voltage to the electrical vehicle, and a switch connected in series between the first input or the secondary input and the center tap, and whereby the electrical vehicle charging device is adapted for closing and/or opening the switch depending on a DC voltage level required for charging the electrical vehicle.

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.