Fuzzy system applications for identification of weak buses in power systems

Abstract

In this paper a simple new algorit hm for identifying the weak buses in a power system for voltage stability study is presented. The proposed algorithm is based on fuzzy set theory. Two membership functions, one for voltage bus, and another for the total reactive power loss at that bus, are assumed. A decision function S is chosen based on the fuzzy multiplication of the two membership functions. The bus having the smallest value for the decision is identified as a weak bus in the system. The proposed algorithm is tested using the standard IEEE 30 bus systems. Two tests are conducted: in the first test, a single-load is changed at a certain bus, where the other loads remain unchanged. In the second test, the loads in the system are changed with the same ratio. The results obtained using the proposed algorithm agree with those obtained using the sensitivity analysis methods and other previous proposed techniques in the literature.