基于多变量约束GPC的负荷频率控制

Load Frequency Control Based on Multivariable Constrained Generalized Predictive Control

针对现代电力系统的复杂约束处理问题,提出一种基于多变量约束广义预测控制(GPC)的负荷频率控制(LFC)方法。以区域控制误差和部分待约束内部状态为输出变量,构建多变量受控自回归积分滑动平均预测模型,并根据丢番图方程的隐式解进行多变量输出轨迹预测,改善了经典GPC无法直接处理内部状态约束的缺点且减轻了在线计算负担。此外,以最临近历史控制序列的未来时刻控制量预测值代替实时控制律对随机输入延时进行补偿。以水火电混合多区域互联系统为例进行仿真,仿真结果表明,所提控制策略比传统PI控制的控制性能和时滞鲁棒性更优,比经典显式约束GPC的计算实时性更好。

Aiming at the ubiquitous complicated constraint treatment issue in modern distributed power systems,a load frequency control(LFC)scheme based on multivariable constrained generalized predictive control(GPC)is presented in this paper.Taking area control error and some of the system states to be constrained as the output variables,a multivariable controlled auto-regressive integral moving average-based predictive model is established.The predicted output trajectories are obtained by implicitly solving the Diophantine equations.Therefore,the defect of explicit treatments of the internal states in the classic GPC is corrected and the heavy online computation burden is reduced.Besides,the corresponding elements in the latest historical predictive control trajectory instead of the real-time control signal are applied to compensate for the random system input delay.The simulation results of a hydro-thermal hybrid multi-area interconnected system indicate that the proposed control scheme can achieve better comprehensive control performance and time delay robustness as well as faster computation speed in comparison with the conventional PI control and classic constrained explicit GPC,respectively.