A novel high-torque reluctance motor with rare-earth magnet

Iwabuchi, N.; Kawahara, Atsushi; Kume, T.; Kabashima, T.; Nagasaka, Nagahiko

doi:10.1109/28.293708

Cited by 19 publications

(9 citation statements)

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“…He identified that the transverse flux machine as having the best potential, owing to the design having higher power density and efficiency, compared to the longitudinal design. Despite the high shear stress offered by transverse flux machines (up to 200 kN/m 2 [63]), their topology requires structural support and they suffer from low power factor requiring reactive power compensation [64].…”

Section: Linear Generator Typesmentioning

confidence: 99%

A review of wave energy converter technology

Drew

Plummer

Şahinkaya

2009

Proceedings of the Institution of Mechanical Engineers, Part A:

961

504

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Ocean waves are a huge, largely untapped energy resource, and the potential for extracting energy from waves is considerable. Research in this area is driven by the need to meet renewable energy targets, but is relatively immature compared to other renewable energy technologies. This review introduces the general status of wave energy and evaluates the device types that represent current wave energy converter (WEC) technology, particularly focusing on work being undertaken within the United Kingdom. The possible power take-off systems are identified, followed by a consideration of some of the control strategies to enhance the efficiency of point absorber-type WECs. There is a lack of convergence on the best method of extracting energy from the waves and, although previous innovation has generally focused on the concept and design of the primary interface, questions arise concerning how best to optimize the powertrain. This article concludes with some suggestions of future developments.

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Section: Linear Generator Typesmentioning

confidence: 99%

A review of wave energy converter technology

Drew

Plummer

Şahinkaya

2009

Proceedings of the Institution of Mechanical Engineers, Part A:

961

504

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“…The density is only slightly reduced if end-windings are included as their projection is small. For comparison, 'Magnagap' by Yaskawa [4] produces peak force density of 5.0 x 104 N/M2, and the linear motor BL14 by Normag [5] has a peak of 4.8 x 104 N/M2. For higher torques, the axial stack length can be simply scaled from the length for 75 Nm peak torque.…”

Section: Prototype Actuatormentioning

confidence: 99%

High-torque brushless DC motor for a valve actuator

Watterson

Collocott²,

Dunlop³

et al. 2005

2005 International Conference on Electrical Machines and Systems

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The design of a high torque brushless DC motor to replace the induction motor and worm gear for valve actuators is described. Minimum motor cost, short axial length and low electronics rating are achieved by selection of open slots and coils wound on bobbins. First and second harmonic designs are compared, with either 2 or 4 magnet poles facing 3 teeth. As well as being cheaper from having fewer coils, the second harmonic design is found to be superior in having lower copper loss at peak torque. The peak tangential force density across the gap was 5.8 x 104 N/M2.Measurements are reported on 75 Nm and 150 Nm peak torque prototypes, which are intended to "run" at 180 rpm and at 20 Nm and 40 Nm respectively. Though 36 pole motors, their no load loss would be sufficiently low for higher speed operation, even to around 2000 rpm. Successful operation as an actuator was observed on a valve. I. INTRODUCTIONElectric actuators are used in many industries to operate valves for fluid flow control. In the power generation industry in particular, each boiler unit requires dozens of actuators for the control of high pressure and high temperature steam and water. Common valve types are quarter-turn butterfly valves and globe valves. Globe valves have an axisymmetric plug which moves linearly between two end-stops or "seats", via the screw action of the threaded valve stem within the threaded valve body, with typically tens of turns required for full travel.A typical commercial multi-turn valve actuator features a fixed speed induction motor driving a worm gear of high gear ratio, e.g. 40:1. Problems associated with the gearing include its size, low efficiency (typically 40°/O), need for lubrication service, and wear. A drawback for the actuator manufacturer in the use of mains frequency induction motors is that a large number of combinations of motor pole numbers and gear ratios are needed to span the required range of actuator torques and speeds. This paper reports the development of a direct drive brushless DC motor and 3-phase electronic controller to replace the induction motor and worm gear, thus eliminating the gearbox problems and enabling precise, variable speed operation with only a small range of motors. The elimination of the worm gear demands a high torque capability for the brushless DC motor. The emphasis in this paper will be on the design of a motor for high peak torque at low speed. Motors for peak torque actuator ratings of 75 Nm and 150 Nm are described. The project has been mentioned previously [1] but this is its first thorough description outside patent applications.

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“…As with a conventional electrical machine, the useful force in a linear machine is produced by the interaction of current carrying conductors with a magnetic field known as the Lorentz force. If the magnetic field (B) and the current (I) in a conductor of length l are perpendicular, the Lorentz force is given by (16) where q is the charge travelling along a conductor at a velocity v.…”

Section: Generator Reaction Force Modelmentioning

confidence: 99%

Reaction force control of a linear electrical generator for direct drive wave energy conversion

Shek

Macpherson

Mueller

et al. 2007

IET Renew. Power Gener.

110

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Direct drive wave energy converters have been proposed in view of the disadvantage of mechanical complexity and low conversion efficiencies in conventional wave energy converters. By directly coupling a linear generator to a reciprocating wave energy device it is suggested that direct drive power takeoff could be a viable alternative to hydraulic and pneumatic based systems. To further realise the benefits of a direct drive system this paper presents a control scheme based on reaction force control to maximise energy extraction. It focuses predominantly on the theoretical analysis of the linear generator reaction force. The modelling, simulation and control of direct drive wave energy conversion are systematically investigated by computer-aided analysis via Matlab/Simulink.

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A novel high-torque reluctance motor with rare-earth magnet

Cited by 19 publications

References 0 publications

A review of wave energy converter technology

A review of wave energy converter technology

High-torque brushless DC motor for a valve actuator

Reaction force control of a linear electrical generator for direct drive wave energy conversion

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