一种非线性滤波器在协调控制系统前馈控制中的应用

An Application of Nonlinear Filter in the Feed-forward Control of Coordinated Control System

西北电网联络线调度下AGC指令复杂多变对火电机组稳定运行不利,为了改善火电机组协调控制前馈系统在AGC指令频繁小幅度波动时造成锅炉燃料量大幅度摆动的问题,研究了一种可变滤波时间的非线性滤波器;依据AGC指令变化幅度设计一种变滤波时间的非线性滤波器,对其动态微分部分输出信号进行增益修正和滤波处理;采集西北某电厂660 MW 24 h AGC指令进行算例分析,通过对比改进前后的燃料量指令证明该非线性滤波器可以实现:AGC指令大幅度变化时,前馈足额快速输出,以维持机前压力稳定;AGC指令小幅度频繁波动时,减小前馈输出幅值并增加滤波时间以减少燃料量波动。通过对比改进前后的燃料量指令,证明了可变滤波时间系数的滤波器具有应用价值。

Under the dispatch of linking-up road, the complexity and variability of AGC command affect the stability of thermal power units. In order to solve the problem that the amount of boiler fuel swings severely when AGC command fluctuations in a small amplitude, this paper explores a filter-time-variant nonlinear filter, which implements gain correction and filtering implementation on the dynamic differential part of output signal according to the variation amplitude of AGC command. In addition, 24 hours＇ AGC command of a 660 MW unit from a power plant in northwest China was collected to analyze the algorithm. After comparing the improved and non-improved fuel command we found the filter-time-variant nonlinear filter can realize the follow effects： when AGC command fluctuations in a small amplitude frequently, it reduces feed-forward output amplitude and increases filtering time to reduce the fluctuation of fuel amount. Thus, the result shows that this filter has a considerable effect on the coordinated control system of a 660MW unit.