skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Radial-Gap Permanent Magnet Motor and Drive Research FY 2004

Abstract

The objective of this task was to study permanent magnet (PM) radial-gap traction drive systems that could meet the U.S. Department of Energy FreedomCAR Program's 2010 goals to expose weaknesses or identify strengths. Initially, the approach was to compare attributes such as physical deformations during operation, performance (torque, power, efficiency versus speed), material requirements (strength), material costs, manufacturability, weight, power density, specific power, reliability, and drivability for specific motors. Three motors selected were the commercially available 60-kW radial-gap surface-mounted PM motor manufactured by UQM Technologies, Inc.; a hypothetical PM motor with rotor-supported magnets similar to the Honda MCF-21; and Delphi's automotive electric machine drive motor, whose rotor is a ferromagnetic cylinder, held at one end by a shaft that supports the magnets on its inner surface. Potential problems have appeared related to PM motors, such as (1) high no-load spin losses and high operational power losses, probably from eddy current losses in the rotor; (2) the undemonstrated dual mode inverter control (DMIC) for driving a brushless dc motor (BDCM) (UQM and Delphi motors); (3) uncertainty about the potential for reducing current with DMIC; and (4) uncertainty about the relation between material requirements and maximum rotor speed. Therefore, the approach wasmore » changed to study in detail three of the comparison attributes: drivability, performance, and material requirements. Drivability and related problems were examined by demonstrating that DMIC may be used to drive an 18-pole 30-kW PM motor to 6000 rpm, where the maximum electrical frequency is 900 Hz. An available axial-gap test motor with 18 poles was used because its control is identical to that of a radial gap PM motor. Performance was analytically examined, which led to a derivation showing that DMIC controls a PM motor so that the motor uses minimum current to produce any power regardless of speed for relative speeds, n = {omega}/{omega}{sub base} {ge} 2. Performance was also examined with efficiency measurements during the 30-kW PM motor test. Material requirements were examined with finite-element analyses (FEA) to determine the speed and location where yield starts and the corresponding deformations and stresses.« less

Authors:
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
885964
Report Number(s):
ORNL/TM-2004/263
TRN: US200617%%275
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; EDDY CURRENTS; EFFICIENCY; INVERTERS; MAGNETS; MOTORS; PERFORMANCE; PERMANENT MAGNETS; POWER DENSITY; POWER LOSSES; RELIABILITY; ROTORS; SPIN; STRESSES; TORQUE; VELOCITY

Citation Formats

McKeever, J W. Radial-Gap Permanent Magnet Motor and Drive Research FY 2004. United States: N. p., 2005. Web. doi:10.2172/885964.
McKeever, J W. Radial-Gap Permanent Magnet Motor and Drive Research FY 2004. United States. doi:10.2172/885964.
McKeever, J W. Fri . "Radial-Gap Permanent Magnet Motor and Drive Research FY 2004". United States. doi:10.2172/885964. https://www.osti.gov/servlets/purl/885964.
@article{osti_885964,
title = {Radial-Gap Permanent Magnet Motor and Drive Research FY 2004},
author = {McKeever, J W},
abstractNote = {The objective of this task was to study permanent magnet (PM) radial-gap traction drive systems that could meet the U.S. Department of Energy FreedomCAR Program's 2010 goals to expose weaknesses or identify strengths. Initially, the approach was to compare attributes such as physical deformations during operation, performance (torque, power, efficiency versus speed), material requirements (strength), material costs, manufacturability, weight, power density, specific power, reliability, and drivability for specific motors. Three motors selected were the commercially available 60-kW radial-gap surface-mounted PM motor manufactured by UQM Technologies, Inc.; a hypothetical PM motor with rotor-supported magnets similar to the Honda MCF-21; and Delphi's automotive electric machine drive motor, whose rotor is a ferromagnetic cylinder, held at one end by a shaft that supports the magnets on its inner surface. Potential problems have appeared related to PM motors, such as (1) high no-load spin losses and high operational power losses, probably from eddy current losses in the rotor; (2) the undemonstrated dual mode inverter control (DMIC) for driving a brushless dc motor (BDCM) (UQM and Delphi motors); (3) uncertainty about the potential for reducing current with DMIC; and (4) uncertainty about the relation between material requirements and maximum rotor speed. Therefore, the approach was changed to study in detail three of the comparison attributes: drivability, performance, and material requirements. Drivability and related problems were examined by demonstrating that DMIC may be used to drive an 18-pole 30-kW PM motor to 6000 rpm, where the maximum electrical frequency is 900 Hz. An available axial-gap test motor with 18 poles was used because its control is identical to that of a radial gap PM motor. Performance was analytically examined, which led to a derivation showing that DMIC controls a PM motor so that the motor uses minimum current to produce any power regardless of speed for relative speeds, n = {omega}/{omega}{sub base} {ge} 2. Performance was also examined with efficiency measurements during the 30-kW PM motor test. Material requirements were examined with finite-element analyses (FEA) to determine the speed and location where yield starts and the corresponding deformations and stresses.},
doi = {10.2172/885964},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2005},
month = {2}
}

Technical Report:

Save / Share: