Sun Miaoping, Nian Xiaohong, Dai Liqiong, Guo Hua
College of information science and engineering, Central South University, Changsha, China.
College of information science and engineering, Central South University, Changsha, China.
ISA Trans. 2017 May;68:82-89. doi: 10.1016/j.isatra.2017.03.003. Epub 2017 Mar 27.
In this paper, the delay-dependent wide-area dynamic output feedback controller (DOFC) with prescribed degree of stability is proposed for interconnected power system to damp inter-area low-frequency oscillations. Here, the prescribed degree of stability α is used to maintain all the poles on the left of s=-α in the s-plane. Firstly, residue approach is adopted to select input-output control signals and the schur balanced truncation model reduction method is utilized to obtain the reduced power system model. Secondly, based on Lyapunov stability theory and transformation operation in complex plane, the sufficient condition of asymptotic stability for closed-loop power system with prescribed degree of stability α is derived. Then, a novel method based on linear matrix inequalities (LMIs) is presented to obtain the parameters of DOFC and calculate delay margin of the closed-loop system considering the prescribed degree of stability α. Finally, case studies are carried out on the two-area four-machine system, which is controlled by classical wide-area power system stabilizer (WAPSS) in reported reference and our proposed DOFC respectively. The effectiveness and advantages of the proposed method are verified by the simulation results under different operating conditions.
本文针对互联电力系统提出了具有规定稳定度的时滞相关广域动态输出反馈控制器（DOFC），以抑制区域间低频振荡。这里，规定稳定度α用于使s平面上所有极点位于s = -α的左侧。首先，采用留数法选择输入输出控制信号，并利用舒尔平衡截断模型降阶方法得到降阶电力系统模型。其次，基于李雅普诺夫稳定性理论和复平面中的变换运算，推导了具有规定稳定度α的闭环电力系统渐近稳定的充分条件。然后，提出了一种基于线性矩阵不等式（LMI）的新方法来获取DOFC的参数，并在考虑规定稳定度α的情况下计算闭环系统的时滞裕度。最后，在两区域四机系统上进行了案例研究，该系统分别由文献报道中的经典广域电力系统稳定器（WAPSS）和本文提出的DOFC进行控制。不同运行条件下的仿真结果验证了所提方法的有效性和优势。
