大型火电机组协调系统的线性自抗扰控制

Linear Active Disturbance Rejection Control for Coordinated System of Large Thermal Power Unit

针对大型火电机组协调系统的非线性、变参数和多变量强耦合特性,以及机组参与电网调峰调频常处于变负荷工况运行的特点,为提高协调系统的控制性能,以某660MW大型火电机组协调系统为对象,设计了协调系统的线性自抗扰控制器(LADRC),针对锅炉侧的迟滞对锅炉LADRC增加了前馈补偿,同时利用扩张状态观测器以消除内外扰动对系统的耦合影响。在超临界机组全范围仿真平台上,分别采用原PID控制器和改进的LADRC进行降负荷扰动仿真。结果表明,改进后的LADRC控制器对负荷和主汽压力的抗扰控制效果优于PID控制器。改进算法简单,整定参数少,并易于工程应用。

Directing against the features of nonlinear,variable-parameter and strong-coupling in the coordination system of large thermal power units which often participate peak regulation and frequency modulation to meet power grid demand,this paper analyzed the characteristics of the coordinated control system for a 600 MW supercritical power unit. A double linear active disturbance rejection controllers（ LADRC） was designed based on feedforward in the bolier contoller as decoupling compensation set perturbation. we used an extended state observer to estimate the disturbance of unmodeled dynamic and unknown in real-time,and compensated the observed disturbance to the system to eliminate disturbance rapidly and to achieve decoupling of the coordination system. The LADRC was programed with Matlab and real-time data communication between Matlab and a full-scope simulator of the 600 MW supercitical unit was implemented based on UDP / IP protocol. Load-down disturbance tests for both the original PID controller and the LADRC with different parameters were carried out respectively. It is shown that the anti-disturbance control effect of LADRC for load and main steam pressure is significantly better than the PID controller. This LADRC control scheme can achieve good static and dynamic decoupling with stronger robustness and anti-interference ability,and the algorithm is simple,with less parameters to set and easy to apply in engineering.