New Stability Criterion for Nonlinearly Perturbed Load Frequency Control Systems with Communication Delays

This paper proposes a new stability criterion with lower conservation and delay dependence for multi-area LFC scheme via a new relaxed integral inequality, and both time delay and the presence of load disturbance are taken into account into the analysis process. Based on the constructed augmented Lyapunov-Krasovskii (LK) functional, the proposed criterion expressed by linear matrix inequality (LAID is deduced. The derivative of the augmented LK functional is hounded tightly by employing a relaxed integral inequality which is based on the auxiliary function and the extended reciprocally matrix inequality. The load perturbation is modeled as a nonlinear norm-hounded function in the stability analysis. Finally, the obtained stability criterion is detected on the interconnected two-area LFC system, so that the effectiveness of the theoretical results is proved.