Contingency assessment for voltage dip and short term voltage stability analysis

Abstract

This paper proposes a novel approach for contingency filtering, ranking and assessment for contingencies that cause power quality and voltage instability problems. The approach consists of two-block technique: the first block filters out dangerous contingencies from a list of credible contingencies; then second block ranks and assesses them. Apart from ranking contingencies in order of their severity (CSI); a new concept of finding dynamic bus voltage vulnerability index (DBVVI) is proposed and is used to rank buses in order of their vulnerability. This filtering, ranking and assessment (FRA) approach uses decoupled time domain method for analysis. Decouple time-domain method is a good blend of accuracy and computational efficiency. The proposed FRA approach is totally generic; it can adapt itself to any specifics of power system (i.e. modeling, protection), any contingency scenario (i.e. N-1, N-2), and for any type of application (planning, operation). The approach is illustrated on IEEE 39 Bus system. The capability of filtering and ranking methodology is illustrated by its performance criteria: reliability, effectiveness and computational efficiency. Finally, the information obtained from filtering and ranking is used for assessment to provide planner/operator with sound information to aid them in deciding an effective control strategy to make power system more robust.