Electromagnetic design of a new electrically controlled magnetic variable-speed gearing machine

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Design of a new non-rare-earth magnetic variable gear for hybrid vehicular propulsion system

This study presents the design of a new non-rare-earth magnetic variable gear (MVG) with 16 electrically controlled gear ratios, which incorporates both the concept of the magnetic gear and the concept of the memory machine. The high-remanence low-coercivity permanent magnet material: namely, the aluminium–nickel–cobalt is adopted to realise the controllable gear ratios. The key is to design the stationary ring newly integrated with magnetising windings in such a way that 16 sets of gear ratios can be achieved so as to fulfil different driving requirements and road conditions. First, the original MVG, the improved MVG and the proposed MVG are discussed. Then, a comprehensive analysis of the proposed MVG is conducted. Consequently, the proposed MVG is extended to electronic-continuously variable transmission for hybrid vehicular propulsion. By using finite element analysis, the electromagnetic performances of three MVGs at various gear ratios are evaluated, hence validating the theoretical design. Moreover, the process of gear-ratio-changing is simulated and analysed. A quantitative comparison among these MVGs is also carried out. Hence, the corresponding validity can be further verified.postprin

Overview of permanent-magnet brushless drives for electric and hybrid electric vehicles

With ever-increasing concerns on our environment, there is a fast growing interest in electric vehicles (EVs) and hybrid EVs (HEVs) from automakers, governments, and customers. As electric drives are the core of both EVs and HEVs, it is a pressing need for researchers to develop advanced electric-drive systems. In this paper, an overview of permanent-magnet (PM) brushless (BL) drives for EVs and HEVs is presented, with emphasis on machine topologies, drive operations, and control strategies. Then, three major research directions of the PM BL drive systems are elaborated, namely, the magnetic-geared outer-rotor PM BL drive system, the PM BL integrated starter-generator system, and the PM BL electric variable-transmission system. © 2008 IEEE.published_or_final_versio

A magnetless axial-flux machine for range-extended electric vehicle

published_or_final_versio

Loss analysis of permanent magnet hybrid brushless machines with and without HTS field windings

This paper presents and implements the power loss analysis of a new kind of permanent magnet hybrid brushless (PMHB) machines with and without using high-temperature superconductor (HTS) field windings. The circuit-field-torque time-stepping finite element method together with experiential equations is developed to perform power loss analysis of the PMHB machine. Experimentation is carried out to verify the proposed loss analysis. © 2006 IEEE.published_or_final_versio

Design of dual-magnet memory machines

The memory machine, which adopts the aluminum-nickel-cobalt (AlNiCo) as the permanent magnet (PM) material, has attracted a wide attention. In this paper, by incorporating two kinds of PM materials including the neodymium-iron-boron (NdFeB) and the AlNiCo, the dual-magnet memory machine is proposed, which has more distinguished merits than its single-magnet counterpart. Due to the high coercivity of the NdFeB, the overall power density is augmented notably. Also, the risk of accidental demagnetization is significantly reduced. Most importantly, the design on how to combine these two kinds of PMs is discussed in detail, with emphasis on their shape, thickness and relative position. Both simulation and experimentation are given to illustrate the validity of the proposed design. © 2011 IEEE.published_or_final_versionThe 2011 International Conference on Electrical Machines and Systems (ICEMS 2011), Beijing, China, 20-23 August 2011. In Proceedings of ICEMS, 2011, p. 1-

An efficient wind-photovoltaic hybrid generation system using doubly excited permanent-magnet brushless machine

With ever-increasing concerns on energy issues, the development of renewable energy sources is becoming more and more attractive. This paper first reviews both the wind power and photovoltaic (PV) power generation techniques and their maximum-power-point tracking (MPPT) methods. Then, a new stand-alone windPV hybrid generation system is proposed for application to remote and isolated areas. For the wind power generation branch, a new doubly excited permanent-magnet brushless machine is used to capture the maximum wind power by using online flux control. For the PV power generation branch, a single-ended primary inductance converter is adopted to harness the maximum solar power by tuning the duty cycle. The experimental results confirm that the proposed hybrid generation system can provide high efficiency with the use of MPPT. © 2006 IEEE.published_or_final_versio

A permanent-magnet hybrid brushless integrated starter-generator for hybrid electric vehicles

A new permanent-magnet (PM) hybrid brushless (PMHB) machine is proposed and implemented as the integrated startergenerator (ISG) for hybrid electric vehicles (HEVs). It has the advantages of higher torque density than other PMHB machines and much wider speed range than other PM brushless machines. The key is to tune its dc-field winding current in such a way that three major modes of ISG system operation for HEVs, namely, engine cranking, battery charging, and torque boosting, can be achieved effectively. The finite-element method is employed to simulate its steady-state and dynamic performances. Finally, a 2-kW prototype is constructed and tested to experimentally verify the simulation results and the validity of the proposed ISG system. © 2010 IEEE.published_or_final_versio

Comparison of fault-tolerant operations for permanent-magnet hybrid brushless motor drive

Paper No. CS-06The permanent-magnet hybrid brushless (PMHB) motor adopts both DC field windings and PMs for excitation. It not only offers effective online flux control, but also flexible brushless DC (BLDC) or brushless AC (BLAC) operations. The key of this paper is to investigate two remedial strategies for fault-tolerant operations of the PMHB motor drive under open-circuit faults. First, by utilizing field excitation boosting, the reduced torque due to one phase loss can be remedied, the so-called remedial BLDC operation mode. Second, by reconstructing armature fields due to the healthy phase currents, the reduced torque can also be remedied, the so-called remedial BLAC operation mode. Finally, these two remedial operation modes are compared and verified by experimentation, hence confirming the validity of the proposed fault-tolerant PMHB motor drive. © 2006 IEEE.published_or_final_versionThe 11th Joint Magnetism and Magnetic Materials - INTERMAG Conference, Washington, DC., 17-21 January 2010. In IEEE Transactions on Magnetics, 2010, v. 46 n. 6, p. 1378-138

A novel flux-controllable vernier permanent-magnet machine

Session GR: Permanent Magnet Special Motors (Poster Session): GR-01By artfully integrating the vernier structure and the DC field winding together, a novel flux-controllable vernier permanent-magnet (FCVPM) machine is proposed, which has the merits of offering high torque output at low speed operation and the flux weakening control at high speed operation. The key is to use the flux modulation poles to modulate the high speed rotating field of the armature winding and the low speed rotating field of the PM rotor, thus achieving the gear effect for high torque output. Also, the DC field winding is specially incorporated into the stator embedded slots, which can effectively weaken the airgap flux density, thus realizing the flux weakening control at high speed operation. By using the time-stepping finite-element-method, the basic characteristics, low speed and high speed operation performances of the machine are analyzed, which verifies the validity of the machine design. © 2011 IEEE.published_or_final_versionThe IEEE International Magnetic Conference (INTERMAG2011), Teipei, Taiwan, 25-29 April 2011. In IEEE Transactions on Magnetics, 2011, v. 47 n. 10, p. 4238-424