An alternator with a longer stationary coil support or bobbin and rotor axial and components thereof are provided.

An energy storage system (100) comprises a switched reluctance motor having a rotor (101) and a stator (102). The rotor is arranged to be capable of acting as a flywheel for storing energy. A casing (106) encloses the rotor and stator, and the rotor is supported for rotation on the casing. The energy storage system further includes a base (109) arranged to support the casing. The energy storage system is arranged such that, in use, the axis of the rotor is generally horizontal. An energy storage installation comprising a plurality of energy storage systems is also provided.

Disclosed are various embodiments for reluctance synchronous machines having a rotor comprising a plurality of rotor core assemblies configured to form a reluctance torque tunnel having at least a first reluctance tunnel segment and a second reluctance tunnel segment and a stator having a plurality of coils configured to form a coil winding assembly, the coil winding assembly positioned within the reluctance torque tunnel, such that at least one of the plurality of coils is surrounded by the first reluctance tunnel segment or the second reluctance tunnel segment, alternatively the rotor may be the coil winding assembly and the stator may be the reluctance torque tunnel.

A rotor for a synchronous reluctance machine includes a first layered structure having ferromagnetic sheets stacked in a direction of a quadrature axis of the rotor and being separated from each other by layers of non-ferromagnetic material, a second layered structure similar to the first layered structure, and a ferromagnetic center part between the first and second layered structures in the direction of the quadrature axis and attached to the first and second layered structures. The ferromagnetic center part is a single piece of ferromagnetic material that is wider in a direction of the direct axis of the rotor than in the direction of the quadrature axis. The width of the ferromagnetic center part in the direction of the quadrature axis is greater than a thickness of each ferromagnetic sheet in order to improve the mechanical strength of the rotor.

A rotor for a synchronous reluctance machine includes a first layered structure having ferromagnetic sheets stacked in a direction of a quadrature axis of the rotor and being separated from each other by layers of non-ferromagnetic material, a second layered structure similar to the first layered structure, and a ferromagnetic center part between the first and second layered structures in the direction of the quadrature axis and attached to the first and second layered structures. The ferromagnetic center part is a single piece of ferromagnetic material that is wider in a direction of the direct axis of the rotor than in the direction of the quadrature axis. The width of the ferromagnetic center part in the direction of the quadrature axis is greater than a thickness of each ferromagnetic sheet in order to improve the mechanical strength of the rotor.

An electromechanical system comprising: a rotor comprising a plurality of teeth spaced about a circumference of the rotor, wherein the teeth of the rotor are equally spaced about the rotor according to a tooth spacing angle, and are skewed in an axial direction such that the circumferential positions of the teeth of the rotor vary along the axial length of the rotor, and first and second stator segments, each extending partway about the rotor and comprising a field winding and poles arranged to magnetically interact with the teeth of the rotor such that an alternating current (AC) back-emf is induced in the field winding upon rotation of the rotor. The poles of the first stator segment are angularly displaced about the rotor from the poles of the second stator segment such that the back-emf induced in the field winding of the first stator segment is phase shifted with respect to the back-emf induced in the field winding of the second stator segment.

An electromechanical system comprising: a rotor comprising a plurality of teeth spaced about a circumference of the rotor, wherein the teeth of the rotor are equally spaced about the rotor according to a tooth spacing angle, and are skewed in an axial direction such that the circumferential positions of the teeth of the rotor vary along the axial length of the rotor, and first and second stator segments, each extending partway about the rotor and comprising a field winding and poles arranged to magnetically interact with the teeth of the rotor such that an alternating current (AC) back-emf is induced in the field winding upon rotation of the rotor. The poles of the first stator segment are angularly displaced about the rotor from the poles of the second stator segment such that the back-emf induced in the field winding of the first stator segment is phase shifted with respect to the back-emf induced in the field winding of the second stator segment.

A brushless bi-directional electric machine comprises a housing mounting exciting coils, a rotor and a stator, the exciting coils and the stator being stationary with respect to the housing and the rotor mounted for rotation with respect to the housing. The electric machine comprises a controller configured to control an exciting current supplied to the exciting coils.

A brushless bi-directional electric machine comprises a housing mounting exciting coils, a rotor and a stator, the exciting coils and the stator being stationary with respect to the housing and the rotor mounted for rotation with respect to the housing. The electric machine comprises a controller configured to control an exciting current supplied to the exciting coils.

Disclosed are various embodiments for switched reluctance machines having a rotor comprising a plurality of rotor core assemblies configured to form a reluctance torque tunnel having at least a first reluctance tunnel segment and a second reluctance tunnel segment and a stator having a plurality of coils configured to form a coil winding assembly, the coil winding assembly positioned within the reluctance torque tunnel, such that at least one of the plurality of coils is surrounded by the first reluctance tunnel segment or the second reluctance tunnel segment, alternatively the rotor may be the coil winding assembly and the stator may be the reluctance torque tunnel.