International Scientific Journal


Free piston engine generator is an effective alternative to conventional range ex-tender, which is able to facilitate the transportation sector decarbonization attributed to its high thermal efficiency and ultimate fuel flexibility. However, due to the lack of crankshaft mechanism, stable and robust operation of free piston engine generator is difficult to achieve since various disturbances may exist during its operation. In this paper, a combustion stability control based on active disturbance rejection control algorithm was proposed for a single piston free piston engine generator. To develop this control, a thermodynamic model of the free piston engine generator system was calibrated and validated through experimental data. Afterward, a 2nd order active disturbance rejection control based speed control was developed by leveraging the developed free piston engine generator model. The proposed active disturbance rejection control was employed into multiple abnormal combustion scenarios through a simulation, including various fuel heat released, ignition positions and burn durations, aimed to verify the control ability of rejecting disturbances and enhancing the robustness of the free piston engine generator operation.
PAPER REVISED: 2022-05-30
PAPER ACCEPTED: 2022-06-22
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THERMAL SCIENCE YEAR 2023, VOLUME 27, ISSUE Issue 1, PAGES [233 - 244]
  1. Xiao, J., et al., Motion characteristic of a free piston linear engine, Applied Energy, 87 (2010), 4, pp. 1288-1294.
  2. Kock, F., et al., The free-piston linear generator potentials and challenges, MTZ Worldwide, 74 (2013), 9, pp. 38-43.
  3. Guo, C., et al., Review of recent advances of free-piston internal combustion engine linear generator, Applied Energy, 269(2020), 6, 115084.
  4. Mikalsen, R., Roskilly, A., The control of a free-piston engine generator. Part 1: Fundamental analyses, Applied Energy, 87 (2010), 4, pp. 1273-1280.
  5. Mikalsen, R., et al., Predictive piston motion control in a free-piston internal combustion engine, Applied Energy, 87 (2010), 5, pp. 1722-1728.
  6. Kosaka, H., et al., Development of free piston engine linear generator system part 1-investigation of fundamental characteristics, SAE Technical Paper, 2014. doi: 10.4271/2014-01-1203.
  7. Goto, S., et al., Development of free piston engine linear generator system part 2-investigation of control system for generator, SAE Technical Paper, 2014. doi: 10.4271/2014-01-1193.
  8. Moriya, K., et al., Development of free piston engine linear generator system part3-novel control method of linear generator for to improve efficiency and stability, SAE Technical Paper, 2016. doi: 10.4271/2016-01-0685.
  9. Jia, B., et al., Piston motion control of a free-piston engine generator: A new approach using cascade control, Applied Energy, 179 (2016), 10, pp. 1166-1175.
  10. Li, K., et al., Active motion control of a hydraulic free piston engine, IEEE/ASME Trans Mech, 19 (2013), 8, pp. 1148-1159.
  11. Li, K., et al., Precise piston trajectory control for a free piston engine. Control Engineering Practice, 34 (2015), 1, pp. 30-38.
  12. Zhang, C., et al., Trajectory-based combustion control for renewable fuels in free piston engines, Applied Energy, 187 (2017), 2, pp. 72-83.
  13. Lu, J., et al., Compression Ratio Control of an Opposed-Piston Free-Piston Engine Generator Based on Artificial Neural Networks, IEEE Access, 8 (2020), 6, pp. 107865-107875.
  14. Dinh, N.V., Ocktaeck, L., Piston motion control for a dual free piston linear generator: predictive-fuzzy logic control approach, J.Mech. Sci. Technol. 34 (2020),11, pp. 4785-4795.
  15. Bo, Y., et al., Control of Magnetoelectric Load to Maintain Stable Compression Ratio for Free Piston Linear Engine Systems, Int. J. Struct. Stab. Dynam. 21 (2020), 2150017.
  16. Ahmed, T.R., et al., A review of free piston engine control literature—taxonomy and techniques, Alexandria Eng. J., 61 (2022), 10, pp. 7877-7916 .
  17. Kai, S., Yanlei, Z., A new robust algorithm to improve the dynamic performance on the position control of magnet synchronous motor drive, 2010 In: 2nd International Conference on Future Computer and Communication (ICFCC), Wuhan, China, 2010, Vol.3, pp. 268-272.
  18. Zhu. C.W., Research on single-piston free piston linear generator system, Dissertation for the Master Degree,Shanghai Jiao Tong University, Shanghai, China, 2019 (in Chinese).
  19. Atkinson, C.M., et al, Numerical simulation of a two-stroke linear engine-alternator combination, SAE Transactions, 108 (1999), 1, pp. 1416-1430.
  20. Fredriksson, J., Denbratt, I., Simulation of a two-stroke free piston engine, SAE Technical Paper, 2004. doi: 10.4271/2004-01-1871.
  21. Kim, J., et al., Simulation on the effect of the combustion parameters on the piston dynamics and engine performance using the Wiebe function in a free piston engine, Applied Energy, 107 (2013), 7, pp. 446-455.
  22. Jia, B., et al., Development and validation of a free-piston engine generator numerical model, Conversion and Management, 91 (2015), 2, pp. 333-341.
  23. Mao, J., et al., Parameters coupling designation of diesel free-piston linear alternator, Applied Energy, 88 (2011), 12, pp. 4577-4589.
  24. Hung, N.B., Lim O.T., A study of a two-stroke free piston linear engine using numerical analysis, Journal of Mechanical Science and Technology, 28 (2014), 5, pp. 1545-1557.
  25. Feng, H., et al., Stable Operation and Electricity Generating Characteristics of a Single-Cylinder Free Piston Engine Linear Generator: Simulation and Experiments. Energies, 8 (2015), 1, pp. 765-785.
  26. Li, Q., et al., Simulation of a two-stroke free-piston engine for electrical power generation, Energy & fuels, 22 (2008), 5, pp. 3443-3449.
  27. Yuan, S., Wu, W., Simulation study of a two-stroke single piston hydraulic free piston engine, In Proceeding of the 2008 Asia Simulation Conference-7th International Conference on System Simulation and Scientific Computing, Beijing, China, 2008, pp. 1244-1249.
  28. Huang, L., An opposed-piston free-piston linear generator development for HEV, SAE Technical Paper, 2012, doi: 10.4271/2012-01-1021.
  29. Su, Y., et al., Automatic disturbances rejection controller for precise motion control of permanent-magnet synchronous motors. IEEE Transactions on Industrial Electronics, 52 (2005), 6, pp. 814-823.
  30. Han, J., From PID to active disturbance rejection control, IEEE transactions on Industrial Electronics, 56 (2009), 3, pp. 900-906.
  31. Boldea, I., Linear electric machines, drives, and MAGLEVs handbook, CRC press, FL, USA, 2013.
  32. Wu, D., et al., Tracking control and active disturbance rejection with application to noncircular machining, International Journal of Machine Tools and Manufacture, 47 (2007), 12, pp. 2207-2217.

© 2023 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence