Adaptive Time Delay Compensator (ATDC) Design for Wide-Area Power System Stabilizer

Wide-area power system stabilizer (WPSS) is one of the most potentially effective approaches to damp interarea low frequency oscillations in power systems. When WPSS is implemented in a real project, emphasis should be put on feedback signal delay problem. In order to intensively study the delay of phasor measurement unit data, field tests have been carried out in Guizhou power grid (GZPG), and results show that, in the long-term, the delay might change remarkably under some circumstances, such as when route switches or communication load increases. Therefore, this paper proposes an adaptive time delay compensation method to deal with such kind of delay. Bounded random delay is divided into several intervals and compensators are designed for each delay interval. Then appropriate compensators will be selected according to the delay measured online, based on the switching rules that is also demonstrated in this paper. The delay used here is the average delay before the compensator switching. The proposed compensator is demonstrated in a two area power system. Numerical simulation results show the effectiveness and feasibility of the proposed adaptive compensator. A comparison with conventional methods is also presented. Finally, the proposed method is validated on GZPG based on real-time digital simulations.