Jong-Moo Kim

Fractional Slot Concentrated Winding Permanent Magnet Synchronous Machine With Consequent Pole Rotor for Low Speed Direct Drive

Fractional slot concentrated winding permanent magnet synchronous machines (FSCW PMSMs) are suited for low speed direct drive since they offer comparatively large number of poles, high torque density, and low torque ripple. This paper introduces feasibility study on FSCW PMSMs with consequent pole (CP) rotor for low speed direct drive. A 40 pole-48 slot FSCW PMSM with CP rotor is analyzed and characterized by extensive 2-D finite-element analysis. The analysis reveals the proposed topology can achieve good performance.

Development of a 20-Pole–24-Slot SPMSM With Consequent Pole Rotor for In-Wheel Direct Drive

In-wheel motors bring a fundamental change in electric vehicle technology by removing conventional mechanical components and freeing up space inside the vehicle body. This approach ultimately helps to realize all-wheel independent control for improved vehicle dynamics and increased vehicle design freedom. However, when space allowed for an in-wheel motor is taken into consideration, high torque density, high efficiency, and wide-speed-range capability are typically required. This paper specifically investigates a 20-pole–24-slot surface permanent magnet synchronous motor with consequent pole rotor for in-wheel direct drive since this topology is well suited for high-pole motors and thus high-torque direct-drive applications. Extensive finite-element analysis is carried out to characterize the proposed motor, and the practical feasibility of the proposed motor is discussed. Finally, the validity of the analysis was experimentally verified.

Double-Sided Iron-Core PMLSM Mover Teeth Arrangement Design for Reduction of Detent Force and Speed Ripple

This paper analytically and experimentally shows effectiveness and simplicity of mover teeth arrangement design, which dramatically reduces detent force and consequently speed ripple at low speed. For this purpose, this paper describes two design steps that include the conventional magnetic circuit optimization by response surface methodology (RSM) and a slight modification of the optimized model based on the proposed mover teeth arrangement. Two prototypes were fabricated, tested, and compared from various perspectives. It was experimentally confirmed that the proposed design is very effective in reduction of detent force and speed ripple with the least sacrifice of performance.

Selection of Contactless-Power-Supply Housing Material Considering Eddy Current Loss, Thermal Load, and Structure Safety

This paper deals with the selection of the housing material of the contactless power supplier (CPS) used for the field winding power supply in wound field synchronous machine (WFSM). The housing of the CPS encloses the rotary transformer and the converter of secondary side. The housing prevents the damage of ferrite core in the rotary transformer and the secondary converter due to centrifugal force in the highest speed, 10,000 rpm. Therefore, the housing should have been designed considering not only strengthen, but also lighten. Furthermore, efficiency is also one of important characteristics in power transfer to improve the whole system efficiency. Taking account of aforementioned points, the stainless steel (SUS) and aluminum (Al), which are commonly used as housing materials, were under reviewed as CPS housing. After comparing the characteristic of CPSs according to housing material in term of eddy current loss, thermal characteristic, and mechanical stability, the appropriate housing material is suggested. After that, experimental results deriving from tests are presented to confirm the analysis results.

Design of wound field synchronous machine as an in-axis motor for electric vehicle traction system

This paper presents the design and performance analysis of a wound-field synchronous machine as an in-axis motor for electric vehicle traction system. The design target is that maximum output power is 60kW and the power density is more than 0.95 kW/kg. To improve power density without permanent magnet, the gear was used. Furthermore, to keep the inside of the vehicle structure, two motor was used for one traction system. Therefore 30kW-grade motor was designed. In the initial design process, equivalent magnetic circuit method was used. For the detail design to reduce torque ripple, response surface methodology was used.

Optimal design of in-wheel motor for an E-bike

The aim of this paper is to provide an optimal design of in-wheel motor as an electric bike (E-bike). The in-wheel motor has a direct-driven outer rotor type attached to the E-bikes rear wheel without any gear. The objective of the optimal design of this in-wheel motor is to improve the output characteristics of the motor and to have a stator form to facilitate automatic winding. Response surface methodology was used for the optimal design and 2-dimensional finite element method was used for electro-magnetic field analysis.

Torque improvement of wound field synchronous motor for electric vehicle by PM-assist

In order to improve the performance of the wound field synchronous motor (WFSM), the permanent magnet assist (PM-assist) is investigated in this paper. The effect of the permanent magnet assist is dependent on the inserted position of the permanent magnets. Thus, four models whose permanent magnets are inserted at each different positions are suggested. Then, the most effective position of the permanent magnet is decided by the mean torque per employed amount of the permanent magnet. By inserting the permanent magnets into the decided position of a WFSM designed for a small electric vehicle traction, the PM-assisted WFSM is designed. By comparing the torque and the efficiency of the original WFSM and the PM-assisted WFSM, the effectiveness of the PM-assist is figured out. Finally, the validity of this research is verified by the experiment using the manufactured WFSM.

Optimum design of the single-phase outer rotor type Brushless DC motor for pump application using response surface methodology and Kriging

The single-phase BLDCM(Brushless DC Motor) has many defects. This paper compares optimized single-phase BLDCM with existing commercial single-phase BLDCM and develops single-phase BLDCM with high efficiency, satisfying demanded power and torque in pump system. This paper presents the statistical optimum design of single-phase BLDCM for pump system by ANOVA(Analysis of Variance) to select effective design variables, RSM, Kriging and table of orthogonal array. Comparing existing commercial single-phase BLDCM, optimized single-phase BLDCM has better performance in efficiency by 50.6 % with satisfaction to required performance of motor for pump system (speed [1,800 rpm], torque [2 Nmm]).