This article revisits the study of load frequency control (LFC) problem in an interconnected nonlinear power network under mismatched disturbance. Unlike previous works, a more realistic interconnected power network with nonlinear coupling between control areas and also including nonlinearities like generation rate constraint (GRC) and governor dead band (GDB) is under study. An adaptive super twisting sliding mode controller (ST-SMC) is designed based on system states and estimated disturbance. The nonlinear disturbance observer (NDO) estimates the mismatch between the electrical and mechanical power and then the estimated value is employed in the controller design to compensate the disturbance. The proposed control scheme ensures faster frequency and tie-line power stabilization compared with techniques existing in the literature. The robustness of the proposed design is validated under random varying step load disturbance and with two area four machine Kundur's test system. The closed loop system stability is theoretically proved using the Lyapunov function. Simulation results confirm the effectiveness of the proposed design in a two-area interconnected power network.

中文翻译：

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基于非线性扰动观测器的非线性互联电网自适应超扭滑模负载频率控制

本文重新研究了失配干扰下互连非线性电力网络中的负载频率控制 (LFC) 问题。与以前的工作不同，正在研究一个更现实的互连电力网络，它在控制区域之间具有非线性耦合，还包括发电率约束 (GRC) 和调速器死区 (GDB) 等非线性。基于系统状态和估计扰动设计了一种自适应超扭曲滑模控制器（ST-SMC）。非线性干扰观测器 (NDO) 估计电力和机械功率之间的失配，然后在控制器设计中采用估计值来补偿干扰。与文献中现有的技术相比，所提出的控制方案可确保更快的频率和联络线功率稳定。所提出的设计的鲁棒性在随机变化的阶跃负载扰动和两区四机 Kundur 测试系统下得到验证。利用李雅普诺夫函数从理论上证明了闭环系统的稳定性。仿真结果证实了所提出的设计在两区域互连电力网络中的有效性。