计及反馈信号多时滞特性的广域阻尼控制

广域测量系统是由多种通信媒质组成的复杂网络系统。由于不同通信媒质和装置的通信延迟时间各异且具有随机性,闭环电力系统在数学上是一个典型的非线性、多时滞且变时滞的动力系统。文中首先将非线性多时滞的系统模型线性化为线性多时滞的模型,然后分析了线性多时滞系统的稳定时滞域的拓扑性质,最后根据其拓扑性质设计了对时滞的异步变化不敏感的广域阻尼控制器。时域仿真结果表明:对于2区4机系统,当区内通信和区间通信分别具有不同时滞及其随机性的情况下,所设计的控制器仍能有效阻尼区间联络线上的低频振荡。

Wide-area Damping Control Considering Multiple Delays of Feedback Signals

Wide-area measurement system (WAMS) involves many kinds of communicating channels. Because different channels have different time delays and randomicity of time-delay, the closed-loop power systems ought to be modeled as nonlinear dynamic systems with multiple and varying time delays. Firstly, the above-mentioned model is linearized into a linear time invarying (LTI) system with multiple time delays. Then the topology characteristics of the stable time-delay region of the LTI system with multiple time delays are analyzed and deduced. Finally, based on the topology characteristics of the stable time-delay region, a controller that is not sensitive to the asynchronous variations of time delays is designed. Numerical results on a tow-area four-machine power system demonstrate that the controller derived can damp low-frequency oscillations in the system for the feedback signals with multiple time delays and varying time delays.