Nonlinear PID controller and its applications in power plants

A new control scheme to processes in power plant is proposed in this paper. It provides a means to systematically improve the performance of PID by using nonlinear feedback mechanisms, a nonlinear differentiator, and a unique state and disturbance observer, which forms the basis for an active disturbance rejection control strategy. The proposed methods do not depend much on the mathematical model and is inherently robust. The proposed nonlinear PID algorithm can handles with time-varying, long time delay, nonlinear, strongly coupling processes, and retains the simplicity and intuitiveness of a regular PID design, much making it easier for practitioners to adopt it. Applications to the coordinated fuel combustion, the main steam temperature and main steam pressure systems in a 300 MW power plant are also introduced.