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

Wang, Junnan; Baker, Nick

doi:10.1109/iemdc.2015.7409127

Cited by 7 publications

(17 citation statements)

References 9 publications

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“…Thus the yoke thickness of the mover core can be much thinner and even the employment of nonmagnetic and lightweight materials (aluminum alloy for an example) can be an acceptable option [29]. The quasi-Halbach array showed the best average performance in force capacity, moving mass according to the simulation researches, so it can improve the overall performance of the SMPMLEMs [23].…”

Section: Different Flux Type Permanent Magnet Lemsmentioning

confidence: 97%

“…Permanent magnet linear electric machine (PMLEM) is the best option for LEM due to its high efficiency and high power-to-weight ratio. The main kinds of PMLEMs being investigated for the FPLG applications are surface mounted PMLEM (SMPMLEM), transverse flux PMLEM (TFPMLEM), and flux switching PMLEM (FSPMLEM) [23,24].…”

Section: Different Flux Type Permanent Magnet Lemsmentioning

confidence: 99%

“…Energies 2018, 11, x FOR PEER REVIEW 4 of 21 be much thinner and even the employment of nonmagnetic and lightweight materials (aluminum alloy for an example) can be an acceptable option [29]. The quasi-Halbach array showed the best average performance in force capacity, moving mass according to the simulation researches, so it can improve the overall performance of the SMPMLEMs [23]. The TFPMLEMs have flux concentrated PMs on the mover and transverse winding in stators, and the current flow is parallel to the direction of motion as shown in Figure 3.…”

Section: Different Flux Type Permanent Magnet Lemsmentioning

confidence: 99%

“…And numerical optimization results of 3D FEA concluded that the FSPMLEMs were uncompetitive compared to the TFPMLEMs due to the large flux leakage even with improved tooth structure. However, complex structure and low power factor for TFPMLEMs remain to be solved [23,31,34]. Compared to SMPMLEMs, both of them suffered from a large moving mass which would result in low motion frequency and low dynamic response.…”

Section: Different Flux Type Permanent Magnet Lemsmentioning

confidence: 99%

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A Review of the Design and Control of Free-Piston Linear Generator

et al. 2018

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The Free-piston linear generator (FPLG) is a novel energy converter which can generate electrical energy and is regarded as a potential technology for solving the restriction of the short driving range of electric vehicles. Getting rid of the crank and flywheel mechanism, FPLG obtains some advantages of a variable compression ratio, compact size, and highly-efficient power generation. Linear electric machine (LEM) design and piston motion control are two key technologies of FPLG. However, they are currently the main obstacles to the favorable performance of FPLG. LEM being used to drive the piston motion or generate electric energy is an integrated design including a motor/generator. Various types of LEMs are investigated, and suitable application scenarios based on advantages and disadvantages are discussed. The FPLG's controller is used to ensure stable operation and highly-efficient output. However, cycle-to-cycle variations of the combustion process and motor/generator switching make it difficult to improve the performance of the piston motion control. Comments on the advantages and disadvantages of different piston motion control methods are also given in this paper.The piston moves freely between TDC and bottom dead center (BDC), and its motion is determined by the resultant force that is acting upon it, including gas pressure force, electro-magnetic force, and rebound force [8][9][10]. The piston motion must be controlled by an electronic control system-an electronic crankshaft, which is an integrated control of combustion parameters or control variables of the LEM and rebound devices [5]. Moreover, there are cycle-to-cycle variations and periodic large disturbances during the combustion process. As a result, piston motion control is still the biggest challenge of FPLG [11]. Besides, LEM is not only used as a power output unit but also a control unit for adjusting the movement of the piston. For the FPLG, LEM requires high reliability, high precision, high efficiency, and so on. Various structures of LEM designed by many teams around the world have been investigated, but none of these meet all of the requirements due to the short stroke, high frequency, and high acceleration.In order to lucubrate the current existing problems, this paper reviews the key technologies of LEM design and FPLG motion control. Firstly, several basic structures of FPLG are introduced, and both their advantages and disadvantages are analyzed. Afterwards, according to the different types of structure, corresponding advantages and disadvantages of LEMs are presented. With respect to the existing LEMs, they are classified according to the different flux path and topology structures in the third section. Finally, different starting methods are introduced based on the FPLG's structure. In terms of power generation stage, piston motion control strategies are divided into three forms and introduced based on their control variables. They include three categories: active combustion parameters control, active LEM control, and the mixed cont...

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Section: Different Flux Type Permanent Magnet Lemsmentioning

confidence: 97%

Section: Different Flux Type Permanent Magnet Lemsmentioning

confidence: 99%

Section: Different Flux Type Permanent Magnet Lemsmentioning

confidence: 99%

Section: Different Flux Type Permanent Magnet Lemsmentioning

confidence: 99%

See 2 more Smart Citations

A Review of the Design and Control of Free-Piston Linear Generator

et al. 2018

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“…The FS is a further development of the MP, based on the hypothesis that by moving the magnets to the stator side, it may give better magnet utilisation by removing magnet material from the overhang area [7,11].…”

Section: Introductionmentioning

confidence: 99%