负荷频率控制系统的线性自抗扰控制

本文研究负荷频率控制系统的线性自抗扰控制(linear active disturbance rejection, LADRC)方法. 考虑负荷频率控制系统的模型及结构, 本文首先通过一仿真例子分析了二阶和三阶LADRC在单区域电力系统的控制性能,指出二阶LADRC在负荷频率控制中的限制. 随后本文针对负荷频率控制中存在的发电速率约束(generation rate constraint, GRC)这一实际问题, 提出一种anti-GRC补偿方案. 该方案将汽轮机理论输出与实际输出误差作为扰动输入, 利用扩张状态观测器进行估计, 从而使LADRC能够快速补偿该误差, 达到抗积分饱和的作用. 最后, 本文将LADRC设计方法推广到具有再热汽轮机和水轮机系统以及多区域电力系统. 仿真表明LADRC是一种独立于模型的普适性控制结构, 所需整定参数少, 能够取得比PID控制更好的抗干扰性能, 可以应用到负荷频率控制系统中.

Linear active disturbance rejection control for load frequency control of power systems

We apply the linear active disturbance rejection approach (LADRC) to the load-frequency control (LFC) of power systems. Considering the model and the structure of the controlled system, we analyze a second order and a third order LADRCs for a single-area power system with non-reheated turbine; and reveal the limitations of the 2nd-order LADRC. To deal with the generation rate constraint (GRC) of the system, we propose an anti-GRC scheme for LADRC, where the error between the computed output and the real output of the turbine is fed back to the extended state observer for fast compensation of the windup. Finally, the LADRC is extended to power systems with reheated and hydro-turbines, and multi-area power systems. It is found that LADRC is a model-free control method with only two tuning parameters. Thus, it is very practical in industrial control. Simulation examples show that LADRC can reduce the load disturbance very well and is readily applicable to the load-frequency control system.