Ying Fan

An improved magnetic-geared permanent magnet in-wheel motor for electric vehicles

This paper introduces an improved magnetic-geared permanent magnet (MGPM) in-wheel motor with high power density and torque density for electric vehicles (EVs). Due to the integrating of the magnetic gear and omitting of the gear inner rotor, the motor can achieve the low speed direct driving and high speed compact designing requirements with even simple structure. The principle and optimized structure are described. A 750w optimized motor is designed and analyzed by finite element method. The simulation results validate that the MGPM in-wheel motor can be operated at low speed, high efficiency and high torque. It is suitable for direct-driving EVs.

A double-stator permanent magnet brushless machine system for electric variable transmission in hybrid electric vehicles

In this paper, a totally brushless electric variable transmission (EVT) machine system is proposed for hybrid electric vehicles (HEVs). The key is to cascade a double-stator permanent-magnet brushless (DS-PMBL) machine with an induction motor to form a new EVT machine system. It not only provides the merits of power splitting as other EVT systems, but also offers the unique advantage that the whole machine system does not involve any carbon brushes or slip rings. Hence, throughout the whole driving profile of HEVs, the proposed machine system can enable the engine operating at its optimal operation area at which its efficiency is the maximum. The control strategy and operation modes of the proposed EVT machine system are elaborated. The validity of system operation is verified by computer simulation. Finally, a DS-PMBL machine prototype is tested to verify its functionality.

Bi-directional converting technique for Vehicle to Grid

This paper presents a bi-directional converter based on Vehicle to Grid (V2G) conception. Combined with the corresponding control, the proposed circuit model can achieve EVs battery charging and grid-connection perfectly. With respect to control strategy, proportional resonant controller (PR) instead of PI can achieve the output with no static error in AC transient feedback and a good performance. Based on the Matlab/Simulink, the converter is analyzed. Furthermore, the converter is designed and built for experimentation. Both simulation and experimental results are given to verify the performance of the converter.

The Improved Direct Torque Control of a New Self-Decelerating Permanent-Magnet In-Wheel Motor for Electric Vehicles

This paper presents an improved control scheme of a new self-decelerating permanent-magnet (SDPM) in-wheel motor, the direct torque control (DTC) method is adopted based on flux linkage adaptive approach and SVPWM technique. The topological structure and operating principle of the proposed SDPM in-wheel motor for electric vehicles (EVs) is introduced. According to the mathematical model of this motor, the expected voltage calculation and flux linkage adaptive models are established. Furthermore, the improved DTC method based on the proposed PM motor is verified by simulation and experiment results. The results show that the improved DTC algorithm has the merits of rapid dynamic response, low torque and flux linkage ripple, fixed switching frequency, good sinusoidal current, and small reactive current component. Therefore, it can meet the high performance requirement for EVs drive system.

Comparison of New Self-Decelerating Permanent-Magnet Wheel Motors with Two Topologies

This paper proposes a new self-decelerating permanent magnet (SDPM) wheel motor for Electric Vehicles (EVs). SDPM can be utilized for direct-driving areas by the advantages of the high torque density and high efficiency. In this paper, the key is the halbach array is not traditional and can be optimized, it can offer higher effective harmonic components of the magnetic field as well as the pull-out torque than the radial magnetized self-decelerating permanent-magnet (RSDPM) motor. In addition, the adoption of halbach arrays can reduce the flux density of the rotor yoke, the Iron losses can be reduced too. The magnetic field distributions and steady-state characteristics of these two topologies are compared by using the finite element method (FEM). The comparative analysis results shows that the new SDPM motor is particularly suitable for direct driving wheel motor in EVs.

Optimal design of a double-stator permanent magnet brushless machine with series magnetic circuit

This paper presents the optimal design of an 18-slot 8-pole double-stator permanent magnet brushless (DS-PMBL) machine. The key is to optimize the split ratio, namely the ratio of the inner-stator outside diameter to the outer-stator outside diameter, to achieve the maximum torque density under the same copper loss. Both the finite element analysis and experimental results are given to verify the proposed optimal design.