Wide-area measurement system-based transient excitation boosting control to improve power system transient stability

Abstract

Transient excitation boosting control (TEBC) is a cost-effective emergency control technique to improve the power system transient stability. However, it is found in this study that the conventional TEBCs have some drawbacks and may be ineffective or even worsen the system stability in some cases. To overcome these problems, a novel widearea measurement system (WAMS)-based TEBC (WTEBC) is proposed in this study. The proposed control law is as follows: boosting the excitation of the critical machines (CMs) in the critical swing and stopping their excitation boosting as the rotor angles of the CMs drop below a threshold after the critical swing. The implementations of the above control law in the special protection system are also provided. The simulation results from the 4-machine system and the China Southern power grid prove the superiority of the WTEBC over the conventional TEBCs. Furthermore, it also indicates that the stabilising effect is quite significant as long as the round-trip WAMS delay is <0.3 s, which further confirms the feasibility of the WTEBC in the practical engineering.