Study on Temperature Control Strategy of Boiler Main Steam for Frequent Action of AGC Command in Power Grid

Traditional PID is widely used in the main steam temperature control system of thermal power unit Cascade control. Although this control scheme is easy to be debugged on site, it is impossible to solve the problem of large fluctuation and over temperature of steam temperature only by adjusting PID parameters due to the characteristics of variable parameters, large inertia and large time delay of main steam temperature control system. Especially when the AGC command of power grid fluctuates frequently, the conventional control strategy is difficult to deal with, resulting in the change of main steam temperature regulation quality Poor, affecting unit economy and safety. In this paper, the sub PID set value adaptive control logic and desuperheating water injection logic to prevent the main steam temperature overshoot are used to solve the problem of the quality deterioration of the main steam temperature regulation under the frequent fluctuation of AGC instructions.