Abstract:

In order to solve the problem of high reheated steam temperature fluctuation, difficult operation of automatic control and low economical efficiency because of high spraying water in supercritical unit, an advanced reheated steam temperature optimal control strategy being applicable to big lag and nonlinear characteristic was put forward by combining the active disturbance rejection controller (ADRC) with the Smith predictive compensation control. Through the simulation of the reheated steam temperature object in 600 MW supercritical unit, the results show that compared with the traditional reheated steam temperature control system, the proposed advanced reheated steam temperature control strategy can decrease the reheated steam temperature fluctuations, setpoint tracking performance and disturbance rejection can be improved, also the economical efficiency can be raised by reducing the amount of spraying water.

Key words: active disturbance rejection controller (ADRC), reheated steam temperature, Smith predictive compensation, economical efficiency