Browsing by Author "Jin, Meng-Jia"

Now showing 1 - 4 of 4
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    Cogging torque suppression in a permanent-magnet flux-switching integrated-starter-generator
    (2010-09-13T00:00:00Z) Jin, Meng-Jia; Wang, Y.; Shen, Jian-Xin; Luk, Patrick Chi-Kwong; Fei, Wei-Zhong; Wang, Can-Fei
    Permanent-magnet flux-switching (PMFS) machine offers high torque density, impressive flux-weakening capability and mechanical ruggedness because of its distinctive configuration, and is potentially suitable for the application in automotive integrated-starter-generators (ISGs). However, the PMFS machine generally exhibits higher cogging torque compared with other machines commonly used in ISGs. Minimisation of the cogging torque in the PMFS machine for its utility in ISGs is therefore of particular importance. Four rotor topologies are proposed here as cost-effective means to suppress the cogging torque of a PMFS ISG. The validity of the proposed techniques has been confirmed by both two- dimensional finite-element analysis and experimental results. Moreover, the influence on the back electromagnetic force by these techniques is also investigated.
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    Design issues of an IPM motor for EPS
    (Emerald Group Publishing Limited, 2011-12-31T00:00:00Z) Wang, Can-Fei; Shen, Jian-Xin; Luk, Patrick Chi-Kwong; Fei, Wei-Zhong; Jin, Meng-Jia
    In electric power steering (EPS), permanent magnet (PM) brushless ac (BLAC) motors offer distinct advantages over other electric motor types in terms torque smoothness, reliability and efficiency. The design procedure of an interior permanent magnet (IPM) motor used in EPS is presented in this paper. The requirements of the steering system are first introduced, and the machine's specifications are then derived. Critical issues which have considerable impacts on the machine's performance, such as operation mode, rotor structure and slot/ pole combination, are analyzed. Subsequently, a 12-slot/10-pole sinusoidally excited IPM machine with concentrated windings is proposed and optimized based on finite element analysis (FEA) modelling. The losses and efficiency are then computed. Performance predictions from the FEA results confirm all the requirements are met or exceeded. A prototype motor has been built for validation.
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    A novel permanent magnet flux switching machine with an outer-rotor configuration for in-wheel light traction applications
    (IEEE Institute of Electrical and Electronics, 2012-09-30T00:00:00Z) Fei, Wei-Zhong; Luk, Patrick Chi-Kwong; Shen, Jian-Xin; Wang, Yu; Jin, Meng-Jia
    This paper proposes a novel permanent magnet flux switching (PMFS) machine with an outer-rotor configuration for in-wheel light traction applications. The geometric topology of the outer-rotor PMFS machine is introduced and the analytical sizing equations are derived to determine the main design parameters of the machine. Two-dimensional (2-D) Finite element analysis (FEA) models are developed to investigate and optimize the machine performance. Furthermore, the flux weakening capability of the machine is analyzed and further improved by segmental permanent magnets with iron bridges. The machine performance predictions by 2-D FEA models are validated by experimental tests on the prototype machine. The suitability of the proposed outer-rotor PMFS machine for in-wheel light traction application is demonstrated.
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    Sensorless high-speed BLDC machine using hardware-RFO
    (2011-12-31T00:00:00Z) Shen, Jian-Xin; Hao, He; Jin, Meng-Jia; Fei, Wei-Zhong
    High-speed permanent magnet (PM) brushless dc (BLDC) motor often needs a continuous rotor position signal for dynamic phase-advancing control, whist such kind of position signal cannot be directly obtained from the conventional Hall effect sensors or via the traditional back-EMF-based sensorless control strategy. Furthermore, during high-speed operation, the inverter free-wheeling diodes may conduct for more than 30 elec-deg, obscuring the back-EMF zero- crossings. Hence, the traditional back-EMF-based sensorless control strategy becomes unworkable. To overcome these problems, a new sensorless control method is proposed in this paper. It uses full hardware to observe the flux vector which is excited by rotor magnets. Thus, it can provide the rotor position which is the same as the phase angle of the observed flux vector. The proposed sensorless control method is validated with a 2Kw, 85000rpm PM BLDC motor system.