Penulis Santo Wijaya, Keiko Shimizu, Masashi Nakamoto
Sari
The paper presents a feedback control of Linear Quadratic Regulator (LQR) scheme for Selective Catalytic Reduction (SCR) process in combined-cycle (CC) power plants. The SCR process is to reduce NOx emission at the CC power plants, prior to venting into the atmosphere by decomposing process using Ammonia (NH3) at the SCR catalysts. This process can be considered as a nonlinear with time delay system. To improve the process efficiency, we are proposing cascade structure of feedback control system which consists of NOx control and NH3 control that are designed with LQR scheme. A multi-rate sampling system is adopted in the cascade design to cope with a slow SCR process, and a fast NH3 injection system characteristic. Furthermore, the structures of the controllers are designed to be implemented in the power plants control system. Simulation results on actual power plants conditions shows a satisfied control performance and design practicability.
Teks Lengkap:
Referensi
[1] H. Peng, W. Gui, H. Shioya, and R. Zou, A predictive control strategy for nonlinear NOx decomposition process in thermal power plants, IEEE Trans. on Systems, Man, and Cybernetics-Part A:Systems and Humans, vol. 36, no. 5, pp. 904–921, 2006.
[2] M. Nakamoto, T. Kokubo, A. Kamito, and K. Shimizu, Cascade control using GPC and LQR for a NOx reduction process of a thermal power plant (in Japanese), Trans. of the Society of Instrument and Control Engineers, vol. E-2, no. 1, pp. 98–107, 2002.
[3] H. Peng, T. Ozaki, V. Haggan-Ozaki, and Y. Toyoda, A nonlinear exponential ARX model-based multivariable generalized predictive control strategy for thermal power plants, IEEE Trans. Control System Technology, vol. 10, no. 2, pp. 256–262, 2002.
[4] M. Nakamoto, T. Kokubo, A. Nakai, and H. Tanabe, Application of linear quadratic regulator to an interactive flow control system for a thermal power plant (in Japanese), Trans. of the Society of Instrument and Control Engineers, vol. 33, no. 6, pp. 494–501, 1997.
[5] K. Shimizu, M. Nakamoto, T. Kokubo, and H. Tanabe, Generalized predictive control for a NOx decomposition process (in Japanese), Trans. of the Society of Instrument and Control Engineers, vol. 32, no. 6, pp. 912–920, 1996.
[6] M. Nakamoto, K. Shimizu, K. Nagat, and T. Kokubo, Generalized Predictive Control for a NOx Decomposition Process of a Combined Cycle Power Plant, IFAC Control of Power Plants and Power Systems, Mexico, 1995, pp. 251–256.
[7] G. Pannocchia, and J.B. Rawlings, The velocity algorithm LQR: a survey, Technical Report, no. 2001-01, 2001.
[8] D. Flynn, Thermal power plant simulation and control, United Kingdom, The Institution of Electrical Engineers, 2003.