Masaya Inoue

Improvement of a claw pole motor using additional ferrite magnets for hybrid electric vehicles

This paper presents a design and experimental study of a rare-earth less motor for hybrid vehicles. Claw pole motor was chosen for base topology and additional ferrite magnets are installed into the rotor poles in order to increase high torque capability and to reduce low field excitation loss. Some design criteria, test results and comparison with Nd-Fe-B magnet motor are shown.

PWM Carrier Harmonic Iron Loss Reduction Technique of Permanent-Magnet Motors for Electric Vehicles

This paper investigates a method to increase fuel economy of motors for an electric vehicle (EV) traction system. The low-torque region of an EV motor is frequently used in everyday urban driving and in fuel economy measurement. Pulsewidth modulation (PWM) carrier harmonic iron loss accounts for a high percentage of total loss for EV motors in this region. This paper reveals the relationship between phase current and carrier harmonic iron loss for a permanent-magnet synchronous motor (PMSM) in the low-torque region. Thus, a novel carrier harmonic loss reduction technique is proposed and applied to two sets of three-phase windings for a concentrated winding PMSM. The loss is successfully reduced in a 70-kW EV motor as well as a two-dimensional finite-element method (2-D-FEM) calculation. The efficiency of the developed motor is calculated and compared with that of a conventional motor in the JC08 mode driving cycle.

An evaluation of concentrated and distributed windings in interior PM and claw pole motors

This paper describes a method to compare the relative merits of a concentrated and a distributed winding motor. Before the comparison, recent developments of coil manufacturing process for the both winding topologies are reviewed in order to assume appropriate copper fill factor in the comparison. A same frame size and a same rotor model are used in the comparison and only the coil winding topologies are different. The results show the advantages of distributed winding and concentrated winding change with not only motor core length but also output torque density. Another comparison between concentrated winding and distributed winding with a new type claw pole motor is also presented which is expected to be a rare-earth free motor topology.

PWM carrier harmonic iron loss reduction technique of permanent magnet motors for electric vehicles

This paper investigates a method to increase fuel economy of motors for an electric vehicle (EV) traction system. The low-torque region of an EV motor is frequently used in everyday urban driving and in fuel economy measurement. Pulsewidth modulation (PWM) carrier harmonic iron loss accounts for a high percentage of total loss for EV motors in this region. This paper reveals the relationship between phase current and carrier harmonic iron loss for a permanent-magnet synchronous motor (PMSM) in the low-torque region. Thus, a novel carrier harmonic loss reduction technique is proposed and applied to two sets of three-phase windings for a concentrated winding PMSM. The loss is successfully reduced in a 70-kW EV motor as well as a two-dimensional finite-element method (2-D-FEM) calculation. The efficiency of the developed motor is calculated and compared with that of a conventional motor in the JC08 mode driving cycle.

Fundamental characteristics of a claw pole motor using additional ferrite magnets for HEV

This paper presents a specification of a claw pole motor that has a field excitation coil for hybrid electric vehicles. The characteristic of the claw pole motor is no use of Dy and Tb which can increase torque capability. The filed excitation which can be generated by controlling filed current in a rotor provides us controllable efficiency. Additional ferrite magnets are installed between the rotor poles for the purpose of increasing torque capability due to moderating magnetic saturation of each claw. FE analysis and experimental results are shown in this paper.