Development of Free Piston Engine Linear Generator System Part 2 - Investigation of Control System for Generator

Goto, Shigeaki; Moriya, Kaznunari; Kosaka, Hirofumi; Akita, Tomoyuki; Hotta, Yoshihiro; Umeno, Takatoshi; Nakakita, Kiyomi

doi:10.4271/2014-01-1193

Cited by 121 publications

(95 citation statements)

References 7 publications

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“…Considering the above, the determination of the piston velocity needs comprehensive consideration. However, we can give an acceptable value as our design limit referencing similar design specifications and empirical data [12,22,24]. In this work, the velocity is expected to be no higher than 12 m/s in the expansion-generating stroke, and less than 7 m/s in the compression-generating stroke.…”

Section: Energy and Efficiency Distribution Within A Single Operationmentioning

confidence: 76%

Decoupling Design and Verification of a Free-Piston Linear Generator

et al. 2016

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This paper proposes a decoupling design approach for a free-piston linear generator (FPLG) constituted of three key components, including a combustion chamber, a linear generator and a gas spring serving as rebounding device. The approach is based on the distribution of the system power and efficiency, which provides a theoretical design method from the viewpoint of the overall power and efficiency demands. The energy flow and conversion processes of the FPLG are analyzed, and the power and efficiency demands of the thermal-mechanical and mechanical-electrical energy conversion are confirmed. The energy and efficiency distributions of the expansion and compression strokes within a single stable operation cycle are analyzed and determined. Detailed design methodologies of crucial geometric dimensions and operational parameters of each key component are described. The feasibility of the proposed decoupling design approach is validated through several design examples with different output power.

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Section: Energy and Efficiency Distribution Within A Single Operationmentioning

confidence: 76%

Decoupling Design and Verification of a Free-Piston Linear Generator

et al. 2016

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“…The measurements of the engine thermal efficiency were done using the methodology presented in [12]. The measured thermal efficiency of the engine was 56.8 % and the overall engine efficiency (keeping steps of the methodology described in [1][2]) was 43.2 %.…”

Section: Resultsmentioning

confidence: 99%

“…The engine control subsystem is similar to regular one. The generator control subsystem is composed in a manner like in [1][2] with additional incorporated elements from [5][6][7].…”

Section: Synthesis Of New Devicementioning

confidence: 99%

Vehicle hybrid free-piston engine-generator

Nerubenko¹,

Krupenin²,

Nerubenko³

2017

Engineering for Rural Development

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Abstract. The study of dynamical performance and effectiveness of on-board power generators having freepiston linear internal combustion engine combined with electrical generator completed with auxiliary drive is presented. The proposed concept is successfully applicable in all types of automobiles, specifically in hybrid vehicles and electric motor cars, and would be used for a design of all kinds of motor vehicles, cars, trucks, offroad machines, transport and agricultural machinery.Keywords: free-piston linear internal combustion engine, electrical generator, controlled auxiliary engine drive. IntroductionThe on-board power generators presented by free-piston linear internal combustion engine without crankshaft combined with electrical generator are widely discussed in recent publications as a device that radically reshapes the hybrid vehicle powertrain. The studies dealt with systematic analysis and synthesis of the main parts of this type of on-board power generators: free-piston linear internal combustion engine without the crankshaft, electrical generator and the control system interconnecting the two above-mentioned components. An important improvement for free-piston linear internal combustion engine without crankshaft combined with electrical generator is the usage of generating component as a partial auxiliary engine drive developed by the authors of the current study. The term "combined" means that the considered device is assembled as one unit. One of the latest perspective devices is presented in [1; 2], where Toyota Central R&D Labs Inc. demonstrates a free piston engine linear generator consisting of a two-stroke combustion system, a linear generator, and a gas spring chamber. The authors paid a lot of attention (among others) to a. control of precise position of the piston, and its velocity as well; b. periodically stop operation of the generator as a driving motor during the generating operation. The authors wrote that they used two versions of combustion: spark ignition -SI, and premixed charged compression ignition -PCCI. For SI case the power output was 10.4 kW, and overall efficiency was 36.2 %; for PCCI case the power output was 12.7 kW, and overall efficiency was 42.0 %.The industrial evaluation of all existing free-piston engine -electric generating devices reflects two major problems: it is difficult to create the piston motion automatically achieving the desirable top-dead-center (TDC) and bottom-dead-center (BDC) at the necessary moment in the absence of the crankshaft; there is increased the heating problem due to close location of two heat sources, i.e. the piston in the cylinder and the electromagnetic generator. The focus of the current study is development of the auxiliary drive in the generator scheme for raising the effectiveness of free-piston linear internal combustion engine by achieving the stroke parameters and combustion equal to regular values of Internal combustion engine having the crankshaft.

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“…The first one is trajectory tracking control, which means the piston motion is controlled to follow along with a specified reference trajectory [12][13][14][15][16][17]. The second one is specifying a reference current profile to generate an appropriate electromagnetic force for stable operation [5,[18][19][20].…”

Section: Introductionmentioning

confidence: 99%

“…In order to avoid collisions between the piston and the cylinder head, a motion control was presented through giving a desired trajectory that was very similar to the sinusoidal signal. Kosaka and Moriya also presented a trajectory tracking control to operate the piston motion [12,16]. However, in their studies, an inappropriate reference trajectory could have a negative effect on the output power and the system efficiency [13].…”

Section: Introductionmentioning

confidence: 99%

A Free-Piston Linear Generator Control Strategy for Improving Output Power

Zhang

Chen

et al. 2018

Energies

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This paper presents a control strategy to improve the output power for a single-cylinder two-stroke free-piston linear generator (FPLG). The comprehensive simulation model of this FPLG is established and the operation principle is introduced. The factors that affect the output power are analyzed theoretically. The characteristics of the piston motion are studied. Considering the different features of the piston motion respectively in acceleration and deceleration phases, a ladder-like electromagnetic force control strategy is proposed. According to the status of the linear electric machine, the reference profile of the electromagnetic force is divided into four ladder-like stages during one motion cycle. The piston motions, especially the dead center errors, are controlled by regulating the profile of the electromagnetic force. The feasibility and advantage of the proposed control strategy are verified through comparison analyses with two conventional control strategies via MatLab/Simulink. The results state that the proposed control strategy can improve the output power by around 7-10% with the same fuel cycle mass.

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Development of Free Piston Engine Linear Generator System Part 2 - Investigation of Control System for Generator

Cited by 121 publications

References 7 publications

Decoupling Design and Verification of a Free-Piston Linear Generator

Decoupling Design and Verification of a Free-Piston Linear Generator

Vehicle hybrid free-piston engine-generator

A Free-Piston Linear Generator Control Strategy for Improving Output Power

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