Computation of closest steady state voltage stability bifurcation using PSO approach

Considering steady state voltage stability, load margin that calculated by continuation power flow (CPF) tool is limited by two constrains which are called saddle-node bifurcation (SNB) and limit induced bifurcation (LIB). The boundary of the load margin is complex and non-convex, so that the conventional approach for closest bifurcation is most likely to get a local closest solution instead of the global one. This paper presents a new approach, in which continuation power flow and particle swarm optimization (PSO) based on simulated annealing (SA) are both used to calculate the closest bifurcation. The combination approach can search the object in the global scope and have the ability (probability) to jump out of the local extreme value. Case study of IEEE 5 bus test system shows that, the approach presented in this paper is effective in analyzing steady state voltage stability of a power system.