基于扰动观测器的电力系统鲁棒滑模控制器设计

针对多机电力系统中的励磁系统，设计一种基于扰动观测器的滑模控制(Perturbation Observer based Sliding-mode Control, POSMC)以提高系统稳定性。首先，将系统的非线性、参数不确定性、未建模动态和外部时变扰动聚合为一个扰动，同时由一个滑模状态扰动观测器(Sliding-mode State and Perturbation Observer, SMSPO)对该扰动进行实时快速估计。随后，通过滑模控制器对该扰动估计进行在线完全补偿以实现全局一致的控制能力。POSMC具备结构简单、可靠性高、不依赖系统精确模型以及仅需测量发电机功角一个状态量等优点。最后，基于机械功率阶跃变化、三相短路以及发电机参数不确定性三个算例验证了POSMC的有效性和鲁棒性，其能在各种工况下实现最佳的动态性能，有利于电力系统发生故障后恢复稳定运行。

Design of perturbation observer-based sliding-mode controller for power systems

A Perturbation Observer based Sliding-Mode Control (POSMC) is proposed to enhance the stability of multi-machine power systems. First, the nonlinearities, parameter uncertainties, unmodelled dynamics and time-varying external disturbances of the system are aggregated into a perturbation, which is estimated by a Sliding-Mode State and Perturbation Observer (SMSPO) in real-time. Then, the estimated perturbation is fully compensated by the sliding-mode controller to achieve a globally consistent control performance. POSMC has the advantages of simple structure, high reliability and easy implementation, while it does not require an accurate system model and only one state, e.g., rotor angle, measurement is needed. Finally, three case studies, e.g., mechanical power variations, three-phase short-circuit fault and generator parameter uncertainties, are undertaken, which verify the effectiveness and robustness of POSMC, i.e., it can achieve the best dynamic performance under various operation conditions, and can effectively restore the power system after failure.This work is supported by National Natural Science Foundation of China (No. 61963020).