Static simulation of voltage instability considering effects of governor characteristics and voltage and frequency dependence of loads

This paper presents an enhanced continuation power flow algorithm for static power system voltage stability assessment, considering the effect of frequency deviation on loads and generator outputs. In the proposed approach, equations representing generator-governor characteristics as well as voltage and frequency dependence of loads are incorporated into the system of equations of the power flow problem. This augmented system of equations is linearised and solved iteratively in a single frame of reference in order to obtain an equilibrium point for given operative conditions. The proposed method is applied in two power systems and the results are compared with those obtained by a conventional continuation power flow.