Abstract:

The ammonia desulfurization control system in the coal-fired power generation system has the characteristics of time-varying, large delay and large inertia. Aiming at the typical large delay system, a desulfurization control system based on Smith predictor is proposed to improve the real-time performance of the system by offsetting the pure delay link in the controlled object. The Smith predictor relies on an accurate PID model, and there are still uncertainties in the PID parameter tuning in the system. The SOA algorithm is used to adjust the PID parameters, and the absolute error integral ITAE is used as the fitness function. Through the continuous optimization of the fitness value, the best combination of the proportional integral differential coefficient is found. The simulation results show that compared to the desulfurization system under the control of Smith predictor, the new system has good follow ability and rapid response, the adjustment time is reduced to 9% of the original, and the peak time is reduced to 5% of the original, and has a very small overshoot. The real-time and stability of the system are guaranteed. These results indicate that the algorithm is effective for engineering control systems and has a good prospect of popularization and application.

Key words: ammonia desulfurization, Smith predictor, PID parameter tuning, SOA, optimization, real-time tracking, large delay system, process control