Abstract: A high energy density flywheel has a central rotating axle for storing kinetic energy. The flywheel comprises a first member to be operatively mounted around the axle. The first member comprises a first material having a given high mass density enabling a given high kinetic energy storage capacity. The flywheel comprises a second member operatively attached to the first member. The second member surrounds an outside portion of the first member subject to radial forces generated by a rotation of the flywheel. The second member comprises a second material having a given high yield strength enabling a given high maximum rotational speed. The second member enables an operation of the flywheel at a given high flywheel rotational speed greater than the rotational speed that would be allowed by the maximal yield strength of the first material, to thereby provide the flywheel with a given high kinetic energy storage capacity.

Abstract: A dual switching frequency hybrid power converter comprising two different types of power switching element switching at two different frequencies is presented for DC-to-AC and AC-to-DC voltage conversion and for monophase or multi-phase devices with the aim of reducing considerably the conduction and switching losses of those power switching elements. The dual switching frequency hybrid power converter also enables a DC to DC voltage conversion as well as an AC to AC voltage conversion.

Abstract: An system for storing electrical energy over at least a medium term duration. The energy storage system comprises a motor assembly operatively connectable to at least one of an electrical energy source and an electrical distribution network for providing kinetic energy, a flywheel device operatively connectable to the motor assembly for storing at least one part of the kinetic energy, a generator assembly operatively connectable to the flywheel device for receiving at least one portion of the part of the kinetic energy and generating regenerated electrical energy in response thereto, and a control unit for controlling operation of the energy storage system, which enables an energy storage operating mode for storing the part of the kinetic energy into the flywheel device, and an energy supply operating mode for providing at least one portion of the regenerated energy to at least one of the electrical distribution network and an electrical appliance.

Abstract: A system for decoupling a rotor from a stator of a permanent magnet motor and a flywheel storage system using the same are provided. The flywheel storage system uses the permanent magnet motor as a magnetic active coupler to minimize magnetic losses in flywheel energy storage system during the motor-generator electric power transfer for enabling a magnetic field weakening method and a way of cancelling the losses during a conservative mode where the stator is totally decoupled from the rotor. Also, the present invention enables the optimal sizing of a permanent motor-generator to be able to supply a constant power over a large range of rotating speeds.

Abstract: The invention relates to a transverse flux electrical machine, comprising a rotor and a stator. The rotor has magnets, angularly adjacent magnets having magnetic polarizations of opposite directions. The stator has a plurality of magnetic cores annularly disposed along the stator. Each core comprises a U-shaped part and a magnetic foot. The U-shaped part is disposed such that its open side faces the air gap between the rotor and the stator and that a segment of a magnetic flux circulating in the U-shaped part is substantially parallel to the rotation axis. The magnetic foot is assembled to the U-shaped part such that it is contiguous to the air gap. The magnetic foot provides a magnetic pole. An electrical conductor coil is disposed in the interior area of all of the U-shaped parts.