A new hybrid method for on-line dynamic security assessment

This paper presents a new hybrid method called marginally unstable injectio n (MUI). This method incorporates energy function analysis into a time-doma in simulator for transient stability assessment. Using a 'controlled' seque nce of short pseudo-faults and the concept of slow energy function (SEF), t he proposed method provides an improved stability index by impelling a stab le system to a marginally unstable state. The resulting stability index is then utilized for estimating the amount of generation rejection required to maintain transient stability within the framework of on-line dynamic secur ity assessment. The technique developed is applied to a 700-bus North Ameri ca system. (C) 1998 Elsevier Science Ltd. AII rights reserved.