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Title: Torque ripple reduction in electric machines

Patent ·
OSTI ID:1375935
; ; ;

An electric machine, such as an Internal Permanent magnet or Synchronous Reluctance machine, having X phases, that includes a stator assembly, having M slots, with a stator core and stator teeth, that is further configured with stator windings to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface that defines a cavity; and a rotor assembly, having N poles, disposed within the cavity which is configured to rotate about the longitudinal axis, wherein the rotor assembly includes a shaft, a rotor core located circumferentially around the shaft. The machine is configured such that a value k=M/(X*N) wherein k is a non-integer greater than about 1.3. The electric machine may alternatively, or additionally, include a non-uniformed gap between the exterior surface of the rotor spokes and the interior stator surface of the stator.

Research Organization:
GENERAL ELECTRIC COMPANY, Niskayuna, NY) (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
EE0005573
Assignee:
GENERAL ELECTRIC COMPANY
Patent Number(s):
9,742,228
Application Number:
14/057,591
OSTI ID:
1375935
Resource Relation:
Patent File Date: 2013 Oct 18
Country of Publication:
United States
Language:
English

References (18)

Synchronous reluctance electrical motor having a low torque-ripple design patent October 1998
Method and apparatus for torque ripple reduction in sinusoidally excited brushless permanent magnet motors patent April 2002
Rotor having multiple permanent-magnet pieces in a cavity patent March 2009
Electric machine patent March 2011
Cooling system for rotating machine patent August 2011
Dovetail spoke internal permanent magnet machine patent August 2011
Induction motor lamination design patent April 2012
Rotating electric machine having rotor embedded-permanent-magnets with inner-end magnetic gaps and outer-end magnetic gaps, and electric car using the same electric machine patent March 2013
Permanent magnet electric machine and permanent magnet with linearly increasing air gap for an electric machine patent April 2013
Interior permanent magnet synchronous motor patent-application April 2002
Permanent Magnet Embedment Rotating Electric Machine, Motor for Car Air Conditioner, and Enclosed Electric Compressor patent-application November 2007
Permanent-Magnet Reluctance Electrical Rotary Machine patent-application April 2008
Permanent Magnet Rotating Electric Machine and Electric Car Using the Same patent-application July 2009
Induction Motor with Improved Torque Density patent June 2010
Dovetail Spoke Internal Permanent Magnet Machine patent-application November 2010
Fractional Slot Multiphase Machines with Open Slots for Simplified Conductor Insertion in a Stator patent-application January 2011
Rotating Electrical Machine patent-application June 2011
Torque Ripple Reduction in Interior Permanent Magnet Synchronous Machines Using Stators With Odd Number of Slots Per Pole Pair journal March 2010

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