Abstract: This paper proposes a multiplier predictive function control method for the first order plus pure delay object. When the step function is adopted, the optimal control law is obtained. In this control law, the optimal time domain is exponential. Moreover, the paper also proposes multiplier coefficient and calls it predictive adjusting coefficient to simplify the corrected output of the controlled object as the output of the actual controlled object. Thus the optimal control law of multiplier predictive function control is obtained. Generally, the cascade control is adopted in the main steam temperature control system with leading and idle zones, and the main controller is replaced with the multiplier predictive function controller In this paper, a linear correction method for the desuperheater control valve is proposed. The practical applications show that the method presented in this paper is simple and effective, and valuable for popularization.

Key words: thermal power generation unit, coal-fired generation, main steam temperature, control system, predictive function, regulating valve, linear correction