Enedym Inc.

Mcmaster University

Berker Bilgin

Ali Emadi

Yasemin Oner

Jianbin Liang

Nigel Schofield

Lea Pommier

Earl Fairall

Rong Yang

Haoding Li

Brock Howey

The current profile of excitation current provided to the electrical coils of a switched reluctance machine is controlled to reduce acoustic noise. A plurality of potential current waveforms can be evaluated to select a desired waveform that reduces the acoustic noise level of the switched reluctance machine. A cumulative sound pressure level of the switched reluctance machine can be determined for each potential current waveform. The cumulative sound pressure level can be determined based on a plurality of harmonic sound pressure levels expected to result from the potential current waveform. A desired current waveform can be identified as the potential current waveform associated with an optimal cumulative sound pressure level. The desired current waveform can then be applied to the corresponding phase coil of the switched reluctance machine in order to operate the switched reluctance machine while reducing acoustic noise without sacrificing other motor performance metrics.

Acoustic noise reduction for switched reluctance machines

A system for controlling pitch angle of a blade of a wind turbine is provided. The system may comprise a switched reluctance motor and an inverter. The motor may be configured to be positioned at a hub of the wind turbine and coupled to the blade. The motor may have a stator and a rotor. The stator may have: (i) multiple stator poles and (ii) coil windings around each of the multiple stator poles. The rotor may be rotatably mounted with respect to the stator. The rotor may have multiple rotor poles and a rotor shaft configured to be coupled to the blade to control the pitch angle of the blade. The inverter may be configured to supply electrical power to the coil windings to control motion of the rotor shaft in response to receiving a pitch angle control signal from a pitch angle control system of the wind turbine.

Switched reluctance motor drive system for controlling pitch angle of wind turbine blades

A reluctance motor has salient teeth on both the stator and the rotor. The reluctance motor includes electrical coils that are usable to generate magnetic flux to drive rotation of the rotor. Concentrated coil windings are wound around each stator tooth. The electrical coils are arranged across all the stator teeth of the reluctance motor to enable the reluctance motor to be driven by alternating current. The electrical coils are arranged so that, when excited with alternating current, the number of magnetic half-poles is equal to the number of teeth on the rotor. The reluctance machine can operate using an inverter instead of an asymmetric bridge.

Alternating-current driven, salient-teeth reluctance motor with concentrated windings

A three-phase switched reluctance machine has a rotor, a first stator and a second stator. The rotor, first stator and second stator are coaxially and concentrically disposed. The rotor and both the first stator and second stator have corresponding poles. Only one of the stators has coils wound about its poles, while the other stator does not have any coils. A defined relationship between the number of rotor poles, the number of stator poles on the first stator and the number of stator poles on the second stator may improve the torque quality of the switched reluctance machine.

Double-stator single-winding switched reluctance machine

Various embodiments are described herein for switched reluctance machine configurations. In at least one embodiment, a switched reluctance machine configured according to the teachings herein includes an axially extending shaft, an axially extending rotor mounted to the shaft, the rotor having a plurality of salient rotor poles, an axially extending stator disposed coaxially and concentrically with the rotor, the stator having a plurality of salient stator poles protruding radially from the stator towards the rotor poles, a plurality of stator teeth and tooth-tips, and a plurality of electrical coils wound about the stator poles to define a plurality of phases of the switched reluctance machine, where a number of stator poles can be determined according to the following equation and at least one constraint condition: 

Multi-teeth switched reluctance motor with short flux path

Various embodiments are described herein for switched reluctance machine configurations. In at least one embodiment, a switched reluctance machine configured according to the teachings herein comprises an axially extending shaft, an axially extending rotor mounted to the shaft, the rotor having a plurality of salient rotor poles, an axially extending stator disposed coaxially and concentrically with the rotor, the stator having a plurality of salient stator poles protruding radially from the stator towards the rotor poles, a plurality of stator teeth and tooth-tips, and a plurality of electrical coils wound about the stator poles to define a plurality of phases of the switched reluctance machine, where a number of stator poles can be determined according to the following equation and at least one constraint condition: 

Multi-teeth switched reluctance motor

Various embodiments are described herein for switched reluctance machine configurations. In at least one embodiment, a switched reluctance machine configured according to the teachings herein comprises an axially extending shaft, an axially extending rotor mounted to the shaft, the rotor having a plurality of salient rotor poles, an axially extending stator disposed coaxially and concentrically with the rotor, the stator having a plurality of salient stator poles protruding radially from the stator towards the rotor poles, and a plurality of electrical coils wound about the stator poles to define a plurality of phases of the switched reluctance machine, where a number of rotor poles can be determined according to the following equation and at least one constraint condition: 

Switched reluctance machine with short flux path

Various embodiments are described herein for methods and systems for controlling a switched reluctance machine (SRM) having an axially extending rotor mounted to a shaft, an axially extending stator disposed coaxially and concentrically with the rotor, the rotor and stator having a plurality of salient poles, the stator poles protruding radially towards the rotor poles, and a plurality of electrical coils wound about the stator poles including a plurality of separate phase coils defining a plurality of phases of the SRM. In one example embodiment, the method comprises providing a control system operatively coupled to a current controller of the SRM, where the control system is configured to generate a unique set of current reference profiles based on an objective function and at least one constraint function and operating the SRM based on the unique set of current profiles generated by the control system.

Torque ripple reduction in switched reluctance machine

Various embodiments are described herein for switched reluctance machine configurations. In at least one embodiment, a switched reluctance machine configured according to the teachings herein comprises a stator including a predetermined number of salient stator poles (N), a rotor rotatably mounted with respect to the stator, with the rotor comprising a plurality of salient rotor poles, and a plurality of coils provided around the predetermined number of stator poles to form at least one phase of the switched reluctance machine, where the rotor poles and the stator poles are symmetrically disposed, and a number of rotor poles is related to 0&#x25a1; and a number of phases according to: i) (N/m)k ceil (mod(k,m)/m) number of phases, and ii) (N/m)k ceil (mod(k,m/2)/m/2) for an even number of phases, where m is the number of phases, and k is a configuration index based on Nand m.

Switched reluctance machine with even pole-phase index

Various embodiments are described herein for a switched reluctance machine having a rotor excitation. In one example embodiment, the switched reluctance machine comprises a stator and a rotor. The rotor may be disposed inside or outside the stator. The rotor is spaced from the stator, and the rotor and the stator are concentrically disposed. The rotor has a plurality of rotor poles having an excitation source, where the excitation source comprises at least one adjustable parameter. The excitation source is provided by a permanent magnet. The dimensions and various other parameters associated with the permanent magnets are adjustable.

Switched reluctance machine with rotor excitation using permanent magnets

Various embodiments are described herein for switched reluctance machine configurations. In at least one embodiment, a switched reluctance machine configured according to the teachings herein comprises a stator including a predetermined number of salient stator poles (N), a rotor rotatably mounted with respect to the stator, with the rotor comprising a plurality of salient rotor poles, and a plurality of coils provided around the predetermined number of stator poles to form at least one phase of the switched reluctance machine, where the rotor poles and the stator poles are symmetrically disposed, and a number of rotor poles is related to Nand a number of phases according to: i) (Ns/m)k ceil (mod (k,m)/m) for an odd number of phases, and ii) (Ns/m)k ceil (mod(k,m/2)/m/2) for an even number of phases, where m is the number of phases, and k is a configuration index based on Nand m.

Switched reluctance machine with odd pole-phase index

A switched reluctance machine designed for high-speed high-power operation. The switched reluctance machine has a rotor having a plurality of radially extending rotor poles, an interpolar filler positioned between the rotor poles, a stator having a plurality of stator poles extending radially inwardly from the inner surface of a machine frame, a stator winding positioned about each stator pole, wherein the stator wire has a rectangular cross-sectional profile, an axial cooling system, an end turn cooling system, and a cooling jacket positioned radially about the machine frame, and a power source configured to selectively supply electrical power to the one or more stator windings to induce rotation of the rotor.

Growing community of inventors

Hamilton, Canada

Berker Bilgin