传统的阻尼控制器较难适应系统结构与运行方式的变化,导致电网的低频振荡现象仍然时有发生。设计了一种基于广域动态信息的自寻优自适应阻尼控制器。该控制器使用改进的Prony算法,在线分析得到系统弱阻尼区间振荡模式的阻尼比,并据此通过自寻优的方法调整控制器的参数。该方法避免了现有自适应阻尼控制方法中存在的系统降阶模型辨识的困难,其控制效果通过在南方电网直流调制中的仿真应用得到了验证。进一步,实现了该直流自适应阻尼控制器的软硬件系统,并在基于实时数字仿真器(RTDS)与广域测量系统物理装置的实验平台上进行了测试。闭环控制实验结果说明了此自适应策略的有效性及广域阻尼控制的可行性。
Conventional damping controllers cannot adapt effectively to the changes of network structures and operating conditions, therefore, the low-frequency oscillation still occurs frequently. In this paper, a self-searching adaptive damping controller is designed based on wide area dynamic signals. Parameters of the controller are tuned according to the damping ratios of the weakly damped inter-area oscillation modes estimated on line by an improved Prony algorithm. In this approach, the model identification is not included, since it is difficult to guarantee its accuracy in real power systems. The proposed adaptive strategy is verified by numerical simulations of China southern power grid. Furthermore, the adaptive controller is implemented by hardware and tested on the platform of RTDS and WAMS. The close-loop experimental results are also presented to show the effectiveness of adaptive HVDC damping controller and the feasibility of wide-area damping control.