An Improved Smith Predictor for Wide-Area Damping Control Considering Time-Delays in Power System

Abstract

Model identification errors and time delays are often presented in power systems, which will deteriorate the effect of power system wide-area damping control. To solve the problems of random time delays and model parameter identification errors on system damping control, this paper firstly uses the pseudo-random noise excitation as the identification signal and establishes a closed-loop model for the power system under small interference conditions. Secondly, a Vinnicombe-Adaptive Multi-parameter Differential Evolutionary algorithm (VAMDE) proposed in this paper takes into account of the algorithm model identification error, directly predicts the value of the random time delay parameter, and gives the optimal damping controller that can effectively suppress low-frequency oscillations in power system. The most important thing is that the random time delay is compensated by the improved Smith Predictor. Finally, a four-machine and two-area system is tested. Compared with traditional iterative identification method, simulation results show that the proposed method can effectively improve the damping control problem caused by the model identification error and communication time delay.

Keywords

• Radom time delays
• multi-parameter differential evolutionary
• improved Smith predictor
• damping controller
• low-frequency oscillations