TY - JOUR ID - 3406 TI - Multivariable control of an industrial boiler-turbine unit with nonlinear model: A comparison between gain scheduling & feedback linearization approaches JO - Scientia Iranica JA - SCI LA - en SN - 1026-3098 AU - Moradi, Hamed AU - Alasty, Aria AU - Saffar-Avval, Majid AU - Bakhtiari-Nejad, Firooz AD - Centre of Excellence in Design, Robotics & Automation, School of Mechanical Engineering, Sharif University of Technology, Tehran, Iran AD - Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran Y1 - 2013 PY - 2013 VL - 20 IS - 5 SP - 1485 EP - 1498 KW - Boiler-turbine KW - Nonlinear model KW - Multivariable control KW - Gain scheduling KW - Feedback Linearization DO - N2 - Due to demands for the economical operations of power plants and environmental awareness, performance control of a boiler-turbine unit is of great importance. In this paper, a nonlinear multi input-multi output model (MIMO) of a utility boiler-turbine unit is considered. Drum pressure, generator electric output and drum water level (as the output variables) are controlled by manipulation of valves position for fuel, feed-water and steam flows. After state space representation of the problem, two controllers based on gain scheduling and feedback linearization are designed. Tracking performance of the system is investigated and discussed for three cases of ‘near’, ‘far’ and ‘so far’ set-points. According to the results obtained, using feedback linearization approach leads to the more quick time responses with a bit more overshoots (in comparison with the gain scheduling method). In addition, in feedback linearization strategy, input control signals (valves position) actuate in less time with less oscillations. It is observed that in the presence of an arbitrary random uncertainty in model parameters, the controller designed based on feedback linearization is more robust. Finally, according to the phase portraits of the problem, as the desired speed of tracking process is increased, dynamic system tends to demonstrate a chaotic behaviour. UR - https://scientiairanica.sharif.edu/article_3406.html L1 - https://scientiairanica.sharif.edu/article_3406_f2afd3e6735ec841c70e77adebe13fcc.pdf ER -