Identification of weak busbars in large scale power system

This paper presents an improved singular value decomposition method for identifying weak busbars in terms of voltage stability in large-scale power system. It employs a continuation load flow to push the system to the voltage collapse limit, and at that point calculates the indicative voltage stability margin and performs singular value decomposition. This method overcomes the main drawback of the standard singular value decomposition failing to give reliable results when applied to large-scale network. Several techniques, including polar-form optimal multiplier, binomial-searching technique and uniform reactive loading, are introduced in the newly developed algorithm to improve the reliability of weak busbar identification and the accuracy of calculation of voltage collapse indicator. The developed algorithm was applied to small testing systems, as well as large realistic power systems with over 2600 busbars, with satisfactory results.