Effect of Side Permanent Magnets for Reluctance Interior Permanent Magnet Machines

Abstract

1 Abstract -A traditional electric machine uses two dimensional magnetic flux paths in its rotor. This paper presents the development work on the utilization of the third dimension of a rotor. As an example, the air gap flux of a radial gap interior permanent magnet motor can be significantly enhanced by additional permanent magnets (PM) mounted at the sides of the rotor. A prototype motor built with this concept provided higher efficiency and required a shorter stator core length for the same power output as the Toyota/Prius traction drive motor.Index Terms--ac machines, interior permanent magnet, reluctance, electric vehicles.

Study of various slanted air-gap structures of interior permanent magnet synchronous motor with brushless field excitation

“…15 shows the projected efficiency contours using optimal field current for achieving the highest efficiency by controlling the excitation current. This projected efficiency is substantially superior to the efficiency of a Toyota Prius motor which was a baseline motor for this project [4]. This higher efficiency is due to the reduced core loss by controlling air-gap flux through the BFE structure [3].…”

“…Because a DC current controls the intensity of the axial-direction flux, the air-gap flux can decrease for the high-speed operation. The details are presented in [3][4][5][6]12].…”

“…To avoid the primary drawbacks of the IPMSM, a brushless field excitation (BFE) structure is introduced [3][4][5][6]. 1 The submitted manuscript has been authored by a contractor of the U. S. Government under contract no.…”

Analysis of slanted air-gap structure of interior permanent magnet synchronous motor with brushless field excitation

“…This flux is added to the main flux from the PMs inside the rotor and interacts with the stator current to produce motor torque. The details are presented in [3], [4], and [6]. Fig.…”

Comparison of driving characteristics in two kind of control schemes for permanent magnet synchronous motor mounted on electric vehicle

“…By the development of the power electronics technology, practical hybrid electric vehicles and electric vehicles have been commercially available; and the use of those vehicles have been rapidly expanding by increasing awareness of global environmental issues in recent years. Most of those vehicles use permanent magnet synchronous motor (PMSM) as the driving motor [1]- [4] .…”