Design improvement of a new outer-rotor hybrid excitation flux switching motor for in-wheel drive EV

Abstract

-Research and developments of in-wheel motors applied in pure electric vehicles (EVs) propulsion systems have attracted great attention recently. This is due to their definite advantages of great controllability for each independent wheel as well as the availability of more cabin space due to removal of conventional mechanical transmission and differential gears. Moreover, more series batteries can be installed to increase the driving distance. Since the motors are attached directly to the wheel, the major requirements are to have high torque density and efficiency. As one of alternative candidates with high torque possibility, a new design of outer-rotor hybrid excitation flux switching motor for in-wheel drive EV is proposed in this paper. The proposed motor consists of 12 slots of stator poles, and 10 rotor poles, with all active parts are located on the stator. In addition, it has a robust rotor structure which only comprises a single piece of rotor and has a wide range flux control capabilities. Under some design restrictions and specifications for the target EV drive applications, the performance of the proposed machine on the initial design and improved design are analyzed based on 2-D finite element analysis (FEA). The performance of the improved design motor shows that the maximum torque achieved is 81.5% of the target performance, whereas the maximum power has achieved 143.6 kW which is greater than the target value. Thus, by further design refinement and optimization it is expected that the motor will successfully achieve the target performances.

Fundamental study of outer-rotor hybrid excitation flux switching generator for grid connected wind turbine applications

“…The slot area of the armature coil and field excitation coil are calculated by using these equations respectively [6].…”

Design optimization of single-phase outer-rotor hybrid excitation flux switching motor for electric vehicles

“…Where N r is the rotor poles number, Ns is the number of stator slots, q is the number of phases and the natural number is defined as k. For the proposed motor, q is set as single phase, N s is set as 8 and N r is set as 4. In general, the rotation frequency of mechanical, f m and the frequency of electrical, f e for the proposed motor can be articulated as (2), where f e , N r and f m is the frequency of electrical, number of rotor poles and mechanical rotation frequency, respectively. III.…”

“…Hybrid Electric Vehicle (HEV) is conside eco-friendly car and this is highly expected in the future [2]. The important of the ba requirements of an electric motor for HEV high torque, high power density, and const speed as well as high efficiently [3].…”

Topologies of single-phase outer-rotor hybrid excitation flux switching motor for in wheel drive applications

“…Moreover in the year 2015, it is expected that CO 2 emission rate from vehicles will increase two times with economic growth. Hybrid Electric Vehicle (HEV) is considered as an ultimate eco-friendly car and this is highly expected to be popularized in the future [2]. The important of the basic characteristics requirements of an electric motor for HEV drive systems are high torque, high power density, and constant power at high speed as well as high efficiently [3].…”

“…This PMFSM has physical compactness, robust rotor structure, higher torque and power density and high efficiency. All magnets are located at the stator which make the temperature of the magnet can easily be controlled [6]. Thisshows that PMFSM have more advantage when compared with PMSM and SRM [7][8][9][10].…”