Delay-Dependent Robust Load Frequency Control for Time Delay Power Systems

作者：Zhang, Chuan-Ke^*; Jiang, L.; Wu, Q. H.; He, Yong; Wu, Min

来源：IEEE Transactions on Power Systems, 2013, 28(3): 2192-2201.

DOI：10.1109/TPWRS.2012.2228281

• Delay-dependent robust method
• load frequency control
• PID control
• robust performance index
• time delays

The usage of communication channels introduces time delays into load frequency control (LFC) schemes. Those delays may degrade dynamic performance, and even cause instability, of a closed-loop LFC scheme. In this paper, a delay-dependent robust method is proposed for analysis/synthesis of a PID-type LFC scheme considering time delays. The effect of the disturbance on the controlled output is defined as a robust performance index (RPI) of the closed-loop system. At first, for a preset delay upper bound, controller gains are determined by minimizing the RPI. Secondly, calculation of the RPIs of the closed-loop system under different delays provides a new way to assess robustness against delays and estimate delay margins. Case studies are based on three-area LFC schemes under traditional and deregulated environments, respectively. The results show that the PID-type controller obtained can guarantee the tolerance for delays less than the preset upper bound and provide a bigger delay margin than the existing controllers do. Moreover, its robustness against load variations and parameter uncertainties is verified via simulation studies.

• 出版日期2013-8
• 单位中南大学