考虑广域反馈信号时滞影响的附加励磁控制器

Additional Controller of Excitation System Considering Time Delay of Wide-Area Feedback Signal

采用广域信号作为附加励磁控制信号能够有效抑制互联电网的区间振荡,但广域信号在传输和处理过程中的时滞会严重影响系统的稳定性。为此作者提出了一种考虑广域信号延时影响的阻尼互联电网低频振荡附加励磁控制器。该控制器基于电力系统降阶模型,首先考虑了广域反馈信号的时滞,将电力系统建模为时滞微分方程的形式;然后应用时滞系统稳定性理论和线性矩阵不等式(linear matrix inequality,LMI)的处理方法将附加励磁控制器参数的设计转化为求取适当的参数使得含有时滞信号的闭环系统具有最大时滞稳定性的问题;最后应用LMI工具箱和遗传算法优化了附加励磁控制器参数。4机电力系统的动态仿真验证了文中所设计控制器的有效性。

The inter-area oscillation occurred in interconnected power grid can be effectively eliminated by using wide-area feedback signal as additional excitation control signal, however the time-delay of wide-area feedback signal taken place during transmission and processing process in measurement system will seriously affect power system stability. For this reason, a design method for additional excitation controller, which considers the affect of time-delay and can attenuate low frequency oscillation in intercormected power grid, is proposed. Based on reduced-order model of power system, firstly the power system that takes the time-delay of wide area feedback signal into account is modeled as having the form of delay differential equation; then by using the stability theory of time-lag system and the processing method of linear matrix inequality （LMI）, the parameter design of additional excitation controller is transformed into the problem of obtaining proper parameters to make the close-loop system with time-lag signal processing maximum delay stability; finally, by using the LMI toolbox and genetic algorithm, the parameters of additional excitation controller are optimized. Results of dynamic simulation for a 4-machine power system verify the effectiveness of the proposed controller.