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Study of Various Slanted Air-Gap Structures of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

Conference ·
OSTI ID:993784

This paper shows how to maximize the effect of the slanted air-gap structure of an interior permanent magnet synchronous motor with brushless field excitation (BFE) for application in a hybrid electric vehicle. The BFE structure offers high torque density at low speed and weakened flux at high speed. The unique slanted air-gap is intended to increase the output torque of the machine as well as to maximize the ratio of the back-emf of a machine that is controllable by BFE. This irregularly shaped air-gap makes a flux barrier along the d-axis flux path and decreases the d-axis inductance; as a result, the reluctance torque of the machine is much higher than a uniform air-gap machine, and so is the output torque. Also, the machine achieves a higher ratio of the magnitude of controllable back-emf. The determination of the slanted shape was performed by using magnetic equivalent circuit analysis and finite element analysis (FEA).

Research Organization:
Oak Ridge National Laboratory (ORNL); Power Electronics and Electric Machinery Research Facility
Sponsoring Organization:
EE USDOE - Office of Energy Efficiency and Renewable Energy (EE)
DOE Contract Number:
AC05-00OR22725
OSTI ID:
993784
Country of Publication:
United States
Language:
English