考虑通信时滞和采样周期的电力系统负荷频率控制

针对电力系统负荷频率稳定控制问题,本文提出了一种时滞/采样相关的离散负荷频率控制(LFC)方案.首先,考虑通信网络传输时滞和反馈信号采样周期对系统的影响,建立闭环电力系统LFC模型.然后,基于建立的LFC模型,利用双边闭环Lyapunov泛函和LMI技术,提出了低保守性的时滞/采样相关稳定准则和控制器设计方法,确保所提控制方案能在一个较大的通信时滞和采样周期条件下保持电力系统稳定运行.最后,通过单区域和三区域电力系统验证所提方法的有效性.仿真结果表明,所设计LFC方案比现有其他LFC方案的控制性能更佳,鲁棒性更强,并且能在一定大小的通信时滞条件下提升电力系统的动态性能.

Load frequency control for power systems considering communication delays and sampling periods

This paper proposes a delay/sampled-dependent discrete load frequency control (LFC) scheme for the load frequency stability control problem of power systems. First, a LFC model of closed-loop power systems is established by considering the impact of both transmission delays of communication network and sampling periods of feedback signals on the systems. Then, based on the LFC model, by employing a two-side looped Lyapunov functional and LMI technique, a less conservative and delay/sampled-dependent stability criterion and a controller design approach are developed, which guarantee that the proposed control scheme can maintain the system stable operation in a larger communication delay and sampling period. Finally, a one-area power system and a three-area power system are applied to verify the effectiveness of the proposed approach. It is demonstrated from the simulation that the proposed LFC scheme has better control performance and robustness than others in the existing literature, and it can also improve dynamic performance of the power systems under the communication delay of a certain size.