基于LMI的广域时延多机电力系统的控制与稳定性研究

Study on control and stabilization for multi-machine power system with wide-area time-delay by LMI

广域信号通信时延是导致控制器性能下降甚至失效的重要原因之一。针对时滞电力系统的特性,对多机电力系统转子运动方程进行合理的线性化和偏差化,建立时滞线性多机电力系统。通过构造合适的Lyapunov函数导出了基于自由权矩阵的线性矩阵不等式(LMI)理论的广域时延系统稳定性判据,并设计了相应的全状态反馈控制器。与基于二次线性最优的控制方法相比,保守性更小,控制效果有所提高。通过IEEE3机9节点电力系统模型验证了该控制器的有效性。仿真试验结果表明该控制方法能较好地减小时延带来的不利影响。

Time-delay brought by wide-area communication is one of the most important causes leading to the performance degradation and even the failure of the controllers. The motion equation of the generator rotors of the multi-machine power system is linearized and deviated in the paper, in consideration of the characteristics of the time-delay power system. Then, defining a proper Lyapunov function, stabilization criteria based on the linear matrix inequality theory are presented by introducing some weight-free matrices. And the controller with full state feedback is designed. Compared to the linear quadratic optimal control, the controller is less conservative and more effective. The validity of the controller is verified by the IEEE 3-machine 9-bus test system. The simulation results show that the controller can reduce the negative impact caused by the time-delays.