Voltage stability analysis based on limit induced bifurcation

Limit induced bifurcation (LIB), which occurs while reactive power output of generators exceeds the limit or output of dynamic reactive power sources is over-limited, is very dangerous to power system voltage stability. The conditions by which LIB may occurs is given while reactive power is over-limited; a criterion to judge whether voltage stability can be maintained is proposed while LIB occurs due to over-limited reactive power, and an explanation on the mechanism of how LIB influencing voltage stability is given. LIB reflects the importance of dynamic reactive power sources in maintaining system voltage stability, so the influence of increasing reactive power source on LIB is researched. The correctness of the proposed method and the given explanation on the mechanism of LIB are verified by results of digital simulation.