Kobets - Siberian Institute of Power System Designing Novosibirsk, Lenin St. ۴, ۶۳۰۰۹۹ Russia
Nesterenko - Siberian Institute of Power System Designing Novosibirsk, Lenin St. ۴, ۶۳۰۰۹۹ Russia

A set theoretic analysis of load ilow feasibility and stability of a lossless power network with only voltage controlled buses is presented. This analysis is based on the study of points with the maximum power flow on the given cut-sets. The properties of the load flow feasibility/stability region are investigated. `l7ie examples of power network are given where (i) feasibility/stability region is not convex; (ii) feasibility/stability region is not contractile with respect to bus voltages (or to line admittance's); (iii) the closure of stability region differs from feasibility region. It is argued that the feasibility and stability conditions may be corrected by a decrease in bus voltage and/or line admittance.

load flow feasibility region, convex, contractile