In this paper, a novel application of a robust controller for an electronic governor of a small gas engine generator is presented. There are a few studies regarding the fluctuations in the concentration of bio-methane fuel and load fluctuation of a generator using an approximately 1-kW small gas engine generator. For a relatively small-scale local-production-type energy circulation system, such as the gas energy from a Tambo (GET) system, it is necessary to develop a small gas engine generator that can use the generated unpurified bio-methane gas to accommodate the load fluctuation. The GET system is a bio-methane gas production system, utilizing the sustainable resources from a paddy field, without requiring any distinct auxiliary facilities. We have examined the bio-methane gas produced from the GET system as the fuel of a small gas engine generator, which can supply electric energy and thermal energy to a greenhouse. We have studied the application of a robust engine controller by combining a model matching controller and an optimal observer (MM_OBSV controller) with the electronic governor of the small gas engine generator. The results indicate that the control system is adapted for the input disturbance (load fluctuation and modeling error), with the MM_OBSV controller embedded in the electronic governor of the small gas engine generator.

1. [1] K. Saga et al., “Study on Rice Straw Collection System for Bioethanol Production,” J. of Japan Society of Energy and Resources, Vol.29, No.6, pp. 8-13, 2008.
2. [2] C. Yang and M. Sagisaka, “Evaluation of Bioethanol Production System from Rice Straw,” J. of Life Cycle Assessment, Japan, Vol.5, No.4, pp. 501-509, 2009.
3. [3] T. Sawada et al., “Pretreatment of rice straw aiming to eliminate contaminants and useful resource utilization of constituents,” J. of Society of Environmental Science, Japan, Vol.10, No.4, pp. 313-321, 1997.
4. [4] Y. Yamasaki, Y. Nishizawa, and S. Kaneko, “Development of Fuel Flexible Engine System,” Trans. of Japan Society of Mechanical Engineers Series B, Vol.76, No.764, pp. 684-690, 2010.
5. [5] H. Tamura, T. Hirano, and H. Murano, “Construction of The GET System,” Academic J. of Meijo University Faculty of Agriculture, Vol.49, pp. 1-10, 2013.
6. [6] S. Y. Ragadia and Dr. Rajesh C. Iyer, “A Review Paper on Theoretical & Experimental Investigations of a Biogas Engine Technology,” Int. J. of Scientific Research and Development, pp. 2321-0613, 2015.
7. [7] A. Kikusato, “A research on Improving Thermal Efficiency of a Natural Gas Engine by Optimizing Combustion Control Strategy,” 2014.
8. [8] B. Kapadia, “Development of SI engine for 100% biogas operation,” Thesis for the degree of Master of Science, Department of Mechanical Engineering, Indian Institute of Science Bangalore, 2006.
9. [9] R. Nagata, “Application of Biogas Energy,” Japan Society of Mechanical Engineers annual meeting, Vol.2004, No.3, 2004.
10. [10] Y. Sakai et al., “The Performance of a Small-Scale Internal Combustion Engine Using Mixed Gas (CH₄ 60%+CO₂ 40%) as Fuel,” J. of the Society of Agricultural Structures, Japan, Vol.14, No.3, pp. 21-26, 1984.
11. [11] K. Okamura, Y. Dong, K. Takahata, and J. Yang, “On the Development of a Control System for a Small Bio-Methane Gas Engine Generator,” Int. J. Automation Technol., Vol.11, No.3, pp. 519-528, 2017.
12. [12] K. Okamura, K. Takahata, and J. Yamg, “Practice of Development Method for Bio-gas Small Engine Electric Governor Control Law,” J. of Japan Society for Design Engineering, 2017.
13. [13] S. Washino, R. Nishiyama, and H. Arai, “Current status and future trend of engine control,” J. of Society of Automotive Engineers of Japan, Vo.48, No.10, pp. 20-26, 1994.
14. [14] N. Kurihara, H. Kimura, and M. Hoshino, “Advanced control technology for ignition spark engine,” Symposium Text of Society of Automotive Engineers of Japan, No.9802, pp. 25-31, 1998.
15. [15] H. Iwano and H. Ooba, “Trends in Electronic Control Technology for Engines,” J. of Society of Automotive Engineers of Japan, Vol.57, No.2, pp. 12-17, 2003.
16. [16] S. Satou, S. Nakagawa, H. Kakuya, T. Minowa, M. Nemoto, and H. Konno, “Improvement for Torque Control Precision in Torque-Based Engine Control,” Trans. of Society of Automotive Engineers of Japan, Vol.38, No.1, pp. 115-120, 2007.
17. [17] M. Tamura and N. Kajimoto, “A Study of a Natural-Gas-Fueled HCCI Engine Control,” Proc. of Society of Automotive Engineers of Japan, No.92-09, pp. 13-18, 2009.
18. [18] H. Harashima and S. Washino, “Control technology in automobiles centering on engine control,” J. of the Society of Instrument and Control Engineers, Vol.25, No.11, pp. 61-69, 1986.
19. [19] P. R. Crossley and J. A. Cook, “A nonlinear engine model for drivetrain system development,” Control 1991, Int. Conf. on IET, pp. 921-925, 1991.
20. [20] https://www.mathworks.com/help/simulink/examples/modeling-engine-timing-using-triggered-subsystems.html/ [accessed June 1, 2017]
21. [21] T. Hata, T. Izumi, and J. Kawaguchi, “Control in Aerospace System,” Corona Publishing, pp. 37-42, 1999.
22. [22] M. S. Grewal, L. R. Weill, and A. P. Andrews, “Global Positioning Systems, Inertial Navigation, and integration,” A John Willey & Sons, Inc. Publication, pp. 204-206, 2001.
23. [23] T. Higuchi, K. Takahata, K. Okamura, Y. Nomura, and M. Takahama, “Development of vehicle trajectory estimation system using GPS and IMU fusion,” Trans. of Society of Automotive Engineers of Japan, Vol.37, No.6, pp. 21-26, 2006.