Optimization Study of ADRC Anti-Disturbance Improvement in Denitrification of Power Plant

NOx control has always been a difficult problem in power plant process control, often resulting in problems such as excessive ammonia injection and large control fluctuations. To solve this problem, a disturbance-reject control (DR-ADRC) scheme is proposed in this paper. Firstly, the steady-state error of the disturbance channel transfer function is analyzed. The results show that the system under traditional ADRC control is a type I system that can only overcome constant disturbances. For slope and acceleration disturbances, their steady-state errors will not converge to 0. Furthermore, based on the above complex disturbance characteristics, the DR-ADRC structure is proposed by ADRC controller structure modification, which can completely suppress slope disturbances and also have better suppression effects on other types of disturbances. Simulation and actual power plant testing results are given to demonstrate the effectiveness of proposed DR-ADRC method.