Abstract: An inverter system is described. The inverter system includes a DC power source such as a plurality of photovoltaic (PV) panels, an inverter and a controller. The inverter includes a plurality of semiconductor devices (e.g., controllable semiconductor switches such as IGBTs and anti-parallel connected diodes) arranged in a suitable inverter topology. The inverter includes DC input terminals connected to the PV panels by means of a DC link and at least one AC output terminal. When starting the inverter, the controller is configured to enable a short circuit state of the inverter by controlling the semiconductor switches to create a short circuit between the DC input terminals such that the inverter carries a current substantially equal to the short circuit current of the PV panels.

Abstract: There are provided control systems and methods for charging batteries. For instance, there is provided a system for charging at least two batteries. The system can include a set of hardware associated with the at least two batteries, and the at least two batteries can be connected in series. Each battery from the at least two batteries can be associated with a subset of the set of hardware, and one subset of the set of hardware can be configured to control an associated battery independently from another subset of the set of hardware and its associated battery.

Abstract: Electrical power distribution system for supplying a set of fixed-frequency loads and a set of variable-frequency loads, includes a set of at least one fixed-frequency AC voltage generator and a set of at least one variable-frequency AC voltage generator, a DC distribution network supplying the variable-frequency loads by means of inverter stages, a first set of rectifier stages connected between the fixed-frequency generators and the distribution network, and a second set of rectifier stages connected between the variable-frequency generators and the DC distribution network. The first set of rectifier stages includes bidirectional rectifiers capable of providing a bidirectional transfer of power and protection means against fault currents connected between the bidirectional rectifiers and the distribution network.

Abstract: Element of a rotating electrical machine, of the rotor or stator type, comprising a plurality of stacks of magnetic sheets each equipped with a tooth comprising notches intended to accommodate electrical windings, and pins arranged between two successive bundles of sheets forming an air-flow duct. A portion of the pins is distributed asymmetrically on the tooth of the stator or rotor sheet with respect to a median axis of the width of the tooth.

Abstract: A power distribution system includes power converter systems electrically connected to a distribution bus which defines a point of common coupling. Each power converter system includes a power converter with semiconductor switching devices controlled using a pulse width modulation strategy with a switching frequency. A controller for each power converter system applies a spectrum analysis process to the respective power converter system that uses measured or derived zero sequence currents associated with the respective power converter system to determine the location of a ground fault within the power distribution system. Each controller applies a switching frequency process where the switching frequency of the power converter of at least one of the power converter systems is different from the switching frequency of the power converter of at least another one of the power converter systems during at least part of the time that the spectrum analysis process is applied.

Abstract: Provided is a power distribution system that includes a reconfigurable DC/DC power converter configured to be connected with an energy storage device at an input end for receiving an input voltage therefrom, and a power electronics building block having a primary bridge unit, a secondary bridge unit magnetically connected with the primary bridge unit, and an outer bridge unit at an output end and connected to an output of the secondary bridge unit, configured to output an output voltage.

Abstract: The invention relates to a supply system for a plurality of loads connected in parallel to a direct current supply bus. The supply system includes a DC supply bus and a plurality of supply lines connected in parallel to the supply bus and supplying the said loads. The supply system includes uncoupling and damping means that is adapted to decrease the unipolar signals travelling within the supply system while the loads are being supplied. The uncoupling and damping means includes at least one inductance arranged in series in at least one of the supply lines. Protective means (are also provided for protection in the event of a fault.

Abstract: A double submodule for a modular multilevel converter comprising a first and second submodule coupled to the first. Each submodule comprises an asymmetric H bridge circuit with two parallel bridges branches, connected between a first and a second direct voltage node of the submodule. Each bridge branch is formed by a series connection from a controllable power semiconductor switch and a diode. A storage capacitor is connected in parallel to the asymmetric H bridge circuit between the first and the second direct voltage node of the submodule. The first and the second submodule are interconnected in such a way that a power semiconductor switch or a diode is part of a bridge branch of the first submodule as well as part of a bridge branch of the second submodule. A modular multilevel converter, comprises a series connection of such double submodules in each of its converter branches, is also disclosed.

Abstract: A subsea assembly comprising an electric subsea machine having an electric motor driving an operator, and a coolant circuit at least partially located in thermal contact with the electric motor, the coolant circuit including a cooling assembly located externally from the subsea machine, the cooling assembly comprising at least a heat transfer element, the subsea machine and the cooling assembly being supported by a common supporting frame; at least a part of the heat transfer element is integrated in the frame.

Abstract: The electrical connection kit (16) for a multipole polyphase stator of a rotating electrical machine comprises a plurality of conductive elements (18, 19, 20, 21) that are superposed and electrically insulated so as to form an electrical connection circuit for each pole of each of the phases. The kit is intended to be grafted on one of the sides of the stator.

Abstract: A method, apparatus, and system to control and test a solar inverter are provided. The method commissions a solar inverter of a solar plant before it is placed into power production. The commissioning process verifies that the inverter to be tested is functioning as intended by connecting a first inverter to the inverter to be commissioned, and using the first inverter to emulate the power grid without being connected to the power grid, and circulate reactive and limited active power between the first inverter and the inverter to be commissioned.

Abstract: There are provided methods and apparatuses for authenticating components in an electric machine. For example, there is provided a method for authenticating parts of an electric machine. The method includes fetching, using a controller, identification data associated with a set of parts and performing a first verification step on the identification data, for each part in the set. The method further includes performing a second verification step on the identification data, in response to the first verification step being successful. The second verification step includes comparing the identification data with data from a database that includes identification information associated with manufactured parts. Furthermore, the method includes, in response to one of the first verification step and the second verification step being unsuccessful, a command to disable the electric machine.

Abstract: Provided is an energy storage system for a marine vessel. The energy storage system includes a battery pack and a storage container (i) configured for housing the battery pack and other components and (ii) including an electrical interface for electrically coupling the battery pack to the vessel. The energy storage system also includes an air blast cooling system (i) mountable to a first section of the container and (ii) for cooling the battery pack and an air conditioning system configured for cooling the other components.

Abstract: This system for converting the electrical energy delivered by a supply network comprises of: a converter and at least one zero-sequence current limiting stage flowing in the converter. The or each limiting stage comprises an active compensation circuit comprising a magnetic component and a voltage source connected to the magnetic component, the voltage source and the magnetic component being adapted to serially inject with the converter an active compensation voltage of the zero-sequence voltages generated by the converter.

Abstract: A method of controlling a power system that includes an electrical machine, e.g., wind turbine generator, a power converter, a DC circuit and a dynamic braking system (DBS) having a braking circuit having a braking resistor and being connected in series to the DC circuit, is provided. The method includes operating the DBS and controlling operation of the electrical machine based on a prevailing temperature of the braking circuit, stopping the electrical machine and controlling the electrical machine to be restarted at its rated output power once the prevailing temperature of the braking resistor reaches or falls below a lower temperature threshold. The electrical machine may be restarted at a lower output power and after restarting, its output power can be increased based on a power starting profile as the braking resistor cools.

Abstract: A stator for an electrical machine (e.g., a motor or generator) is described. The stator includes a stator core consisting of a plurality of axially adjacent generally annular laminations. The stator has axially extending stator teeth between adjacent pairs of which are formed axially extending stator slots for receiving conductors of a stator winding. At least one of the stator teeth includes an axially extending cooling passageway through which a cooling fluid flows in use. The electrical machine can include means for circulating cooling fluid through the cooling passageway(s) to cool the stacked laminations and means for circulating air around the stator along an air cooling circuit where the circulated air is cooled by the stator laminations and there is no need for a separate heat exchanger.

Abstract: There is provided a power converter unit that can include an inverter and a plurality of batteries. The power converter unit can include a battery energy storage system (BESS) and an inverter. The BESS and the inverter can share at least one protection circuit.

Abstract: A power distribution system such as a marine power distribution and propulsion system. The system includes an ac busbar and a plurality of active front end power converters. Each AFE power converter includes a first active rectifier/inverter connected to the busbar and a second active rectifier/inverter connected to an electrical load such as an electric propulsion motor. Power sources are connected to the dc link of the AFE power converters and can be operated under the control of a power management controller or power management system.

Abstract: A rotor for an asynchronous electrical machine comprising a magnetic ring comprising a plurality of layers of ferromagnetic metal sheets stacked axially and a squirrel cage having a plurality of conductive elements regularly distributed over the periphery of the magnetic ring and each having two opposite ends extending axially beyond the magnetic ring and each connected to a short-circuit crown, arranged axially on either side of the magnetic ring and intended to connect the ends of the conductive elements electrically. The rotor is segmented circumferentially into at least two rotor segments.

Abstract: A method of operating a multilevel power converter includes using, through a processing device, a model of an electrical circuit that includes a plurality of switching devices, a plurality of flying capacitors, and an AC terminal. The method also includes regulating a voltage level of the AC terminal through selecting, at least partially based on the model, a possible charging state of the electrical circuit. Each possible switching state has a voltage level that at least partially corresponds to a commanded voltage level for the AC terminal. The method further includes selecting, at least partially based on the model of the electrical circuit and at least partially based on the selected possible switching state, a charging state from a plurality of possible charging states. The method also includes setting the switching state of the electrical circuit at least partially based on the selected charging state of the electrical circuit.