Flux Switching Modulated Pole Machine topologies which offer greater mechanical simplicity

2015 IEEE International Electric Machines &Amp; Drives Conference (IEMDC)

2015

This paper investigates the design of direct drive linear generators for use in Free Piston Engines. Flux switching, modulated pole and surface mounted magnet machines are individually modelled and optimized to react the force of the engine with minimum magnet mass. The mass of magnet used in each design is found to be heavily dependent on the copper loading in the machine and the flux produced at no load. The modulate pole or transverse flux machine, which in other applications gives an extremely efficient use of magnet, is here shown to be more effective than conventional machines but less effective than the flux switching machine.

Section: ) Discussionmentioning

confidence: 99%

Comparison of flux switching and modulated pole linear machines for use with a free piston

2015 IEEE International Electric Machines &Amp; Drives Conference (IEMDC)

2015

“…There is an inherent leakage path circumferentially across adjacent teeth -also shown in Fig 6. The topology was first previously introduced by the authors [20] and is effectively a linear version of the Flux Switching Modulated Pole Machine which was shown in [21] to offer a lower component count and simplified rotor at the expense of an 18% reduction in rated torque per unit magnet mass. The parameters for the FSM are defined in Fig 7. It was found that no rectangular tooth design was compliant with all aspects of the specification.…”

Section: Leakage Pathsmentioning

confidence: 99%

Optimization and comparison of linear transverse flux and flux switching machines

2016 XXII International Conference on Electrical Machines (ICEM)

Atkinson

2016

This paper investigates the design of alternative permanent magnet linear machines for use as the generator in a free piston engine. All of the machines are of a modulated pole structure with three dimensional flux flows. In transverse flux machines such as these, the current flows in a different plane to the flux path, eliminating the usual conflict between electric and magnetic loading. For a linear machine, the mass of magnets used is sensitive to whether the magnets are mounted on the stator or translator. Hence this paper compares transverse flux machines with translator mounted magnets and flux switching machines with stator mounted magnets. A three dimensional finite element analysis of each topology is run through an optimization routine in order to investigate the magnet usage, power factor and other performance criteria. It is concluded that flux switching machine is uncompetitive due to the 65% flux leakage even with improved tooth structure, moreover the transverse flux machine is shown to perform better overall, giving a better power factor, better efficiency and lower translator mass as a whole flux switching machine is not match for free piston engine applications.

“…Fig. 6 gives schematics of a linear FS machine [7,11] flux path in two extreme positions. Compared to the MP the FS has only one magnet energized in the outwards radial direction mounted on a single phase stator.…”

Section: Flux Switching Machinementioning

confidence: 99%

“…In a free piston engine, the total mass of the translator and the peak force capability of the machine both influence the compression ratio, speed profile and hence performance of the engine. Five machine topologies are investigated in this paper: Permanent Magnet (PM) machine with Axial (PMA) [4], Radial (PMR) [4], Quasi-Halbach (PMH) [4][5] magnet array, Modulate Pole (MP) [6] machine and Flux Switching (FS) [7] machine. Four of these topologies have translator mounted magnets whereas the Flux Switching (FS) machine, has the magnets mounted on the stator.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A comparison of alternative linear machines for use with a direct drive free piston engine

8th IET International Conference on Power Electronics, Machines and Drives (PEMD 2016)

2016