The enhanced binary single machine equivalent method for transient stability limit searching

Abstract

This thesis proposes the novel Enhanced Binary Single-Machine Equivalent Method (EBSIME) to provide a fast, robust and systematic approach to search for the transient stability limits (TSLs) of multi-machine power systems. The algorithm is an extension of the SIME method [1] and provides an approach to estimate a transient stability margin for a given scenario – where the system operating conditions and a contingency are specified. The margins estimated for a pair of different scenarios is used to predict and accelerate an iterative search for the TSLs. The search bisects the search bounds whenever the limit prediction using the transient stability margins cannot be applied, thereby ensuring search convergence. Unlike alternative hybrid-direct TSL searching methods the EBSIME algorithm is general and does not require any model simplification, or heuristic tuning for application to the specific power system under investigation. The EBSIME algorithm is designed to be implemented as a peripheral add-on to the standard time domain simulation (TDS) and load-flow software; and does not require access to, or modification of, the primary transient stability analysis software. As some important applications of EBSIME are perceived within the Australian power industry the algorithm has been implemented using PSS®E. In this thesis the algorithm is applied to locate the TSLs on the IEEE simplified 14-generator model of the South-East Australian power system. The results indicate that the EBSIME algorithm can locate the TSL up to 30% faster than a plain binary search, and at worst a few simulation seconds longer than a plain binary search.