A snubber circuit includes a clamp circuit and a voltage conversion circuit. The clamp circuit is configured to absorb electrical energy of a main circuit from a pair of secondary-side voltage points on a secondary side of the main circuit to clamp a secondary-side voltage. The main circuit is of insulating type and is configured to perform electric power conversion. The voltage conversion circuit which is of insulating type is electrically connected to a pair of primary-side voltage points on a primary side of the main circuit and is configured to subject, to direct-current conversion, the direct-current voltage generated by the clamp circuit and output the direct-current voltage to the pair of primary-side voltage points. The voltage conversion circuit includes a transformer, a first capacitance component electrically connected to a primary winding wire of the transformer, and a second capacitance component electrically connected to a secondary winding wire of the transformer.

An apparatus includes a DC-to-AC converter comprising a first output terminal and a second output terminal. The apparatus also includes a DC-to-DC converter comprising a third output. The DC-to-AC converter is configured to receive a DC input voltage from a DC power source, and to produce a first alternating output voltage at the first output terminal, and a second alternating output voltage at the second output terminal. The DC-to-DC converter is configured receive a DC input voltage from the DC power source, and to step down the DC input voltage at the third output.

An arrangement contains an asynchronous machine, which, in generator operation, is configured to feed electric power into an AC network. Accordingly, the asynchronous machine can be dual-fed by a modular multi-stage converter in a matrix configuration. The asynchronous machine has a rotor and the modular multi-stage converter is connected to the rotor of the asynchronous machine.

Apparatuses, systems, and methods for managing power utilizing synchronous common coupling. An apparatus comprises a synchronous common coupling, a plurality of ports, and a plurality of stacks connected through the synchronous common coupling. Each stack comprises at least one stage, with each stage comprising at least one source/load bridge, at least one flux bridge, and a DC bus. The at least one source/load bridge of one stage of each stack is connected to a source or load through one of the plurality of ports, the at least one flux bridge of each stage is connected to an electrically isolated winding in the synchronous common coupling, and the at least one flux bridge of each stage is connected to the at least one source/load bridge of the stage through the DC bus. The synchronous common coupling is configured to exchange power between each of the plurality of stacks.

An energy control circuit is provided. The energy control circuit includes an input circuit; an output circuit; an energy storage circuit coupled between the input circuit and the output circuit; and a controller coupled to the input circuit and output circuit for controlling an amount of energy stored in the energy storage circuit and for controlling a waveform generated by the output circuit using energy stored in the energy storage circuit.

A method of decoupled modulation of a direct AC/AC MMC between a first AC network L having a first waveform and a second AC network R having a second waveform includes performing first and second modulations based on respective reference signals of the first and second AC networks to generate, for each phase leg, first and second integer command signals corresponding to first and second combinations of cell states in the branches of the phase leg needed for generating the first and second waveforms. The method also includes, based on the first and second integer command signals, mapping to each branch a number of cell states to be used for concurrently generating both the first and second waveforms.

Energy packet switches (EPS) employing supercapacitors as storage provide aggregation and delivery of energy to users based on shared-capacitance in a digital power grid. The EPS aggregates energy from one or multiple energy sources, stores and dispatches the energy in discrete amounts as energy packets to one or multiple users. The payload of the energy packet is adjusted by the voltages of the supercapacitors which are used as energy containers for both the EPS and the users. The EPS has a control plane where data transmitted is used to control the operation of the EPS, and a power plane to receive and transmit energy between ports. The power and data planes work in parallel and with a parallel data network. Control and management of the EPS are based on a request-grant transport protocol. The data network is used to receive energy requests and grants, and a granting scheme is used to select which loads are granted energy. By sending addresses of granted loads on the data network and energy on the energy grid, energy is delivered to addressed destinations.

An AC-DC converter 1 has, e.g.: a primary winding 11 to which an alternating-current input voltage Vi is applied; a secondary winding 12 magnetically coupled with the primary winding 11; a bidirectional switch 20 connected in series with the primary winding 11; a resonance capacitor 30 connected in parallel with at least one of the bidirectional switch 20 and the primary winding 11; a resonance inductance component (e.g., a coil 120); a full-wave rectification circuit 40 performing full-wave rectification on an induced voltage appearing in the secondary winding 12; and a smoothing capacitor 50 smoothing the output of the full-wave rectification circuit 40. The alternating-current input voltage Vi is converted directly into a direct-current output voltage Vo, with both a forward voltage and a flyback voltage extracted from the secondary winding 12. The converter 1 further has a switch 200 switching the number of turns of the primary winding.

The invention discloses a power network flexible controller topology shared by modules. Each single-phase topology comprises an AC/AC converter including N.sub.1 CHB modules, and an AC/DC module including NN.sub.1 full-bridge rectifiers; the AC input terminals of N.sub.1 CHB modules are connected in series to form an AC port on one side of the AC/AC converter, the AC output terminals of N.sub.1 CHB modules are connected in series to form the AC port on the other side of the AC/AC converter, the AC input terminals of NN.sub.1 full-bridge rectifiers are connected in series to form the AC port of the AC/DC module, the AC port on one side of the AC/AC converter is connected in series with the AC side port of the AC/DC module and then connected to a first AC network nd the AC port on the other side of the AC/AC converter is connected in series with the DC side port of the AC/DC module.

The invention relates to a voltage transformer for converting a primary-side alternating voltage at a first voltage level into a secondary-side alternating voltage at a second voltage level, the voltage transformer having a DC link in which a first direct voltage generated from the primary-side alternating voltage is converted into a second direct voltage by means of a DC-to-DC voltage converter, characterised in that an output circuit for providing a third direct voltage for the connection of at least one load is coupled to the DC link, in particular to the DC-to-DC voltage converter thereof.