Novel method of assessing voltage stability of a power system using stability boundary in P–Q plane

Abstract This paper proposes a novel method of determining various voltage stability margins of a critical bus or area in a large power system. The method first generates a voltage stability boundary of the critical bus in P – Q plane. A simple equivalent model of the power system is used to generate the stability boundary and it does not require any repetitive load flow simulations. Various voltage stability margins of the critical bus are then directly determined from the generated stability boundary. The proposed method is tested on the IEEE 118-bus system and the results obtained are compared with those found by the conventional method. It is found that the proposed method can provide reasonably good results with very little computational requirement.