Wide-area stability control strategy based on a novel branch transient transfer capability (BTTC) index

Abstract

The deep regulation of generation supply side, the new construction of the power grid and the continuous reshaping of the load structure lead to a more complex disturbance behaviour of the large-scale electric grid. Moreover, the stability situational awareness and control strategy face new challenges due to the appearing multi-group generator swings and transmission weak-line dynamic constraints transfer. In this paper, a novel index, Branch Transient Transfer Capability (BTTC), is designed for transient stability continuous evaluation, which is based on two-machine power system swing characteristics of the voltage node magnitude-phase spatial-temporal distribution and the characteristics of multiple branches power transfers. Therefore, the BTTC index has the unique abilities of the situation single modulation and critical instability judgement. Based on the aforementioned index, a new situational awareness and stability control strategy is proposed for the principle constraints dynamic monitoring and the wide-area control. The effectiveness of BTTC index and stability control strategy is verified by simulations of the Central China and North China HVDC-AC hybrid interconnected model.