Determination of Steady-State Voltage Stability Limit Using P-Q Curve

P -V and Q - V curves are commonly used to determine the steady state voltage stability limit of a power system. In this letter, a new method of determining the voltage stability limit using the P -Q curve is presented. The boundary of the voltage stability region is first determined and then presented in the P -Q plane. For a given operating point, the voltage stability margin can easily be determined from the stability boundary in the P -Q plane. The proposed method of determining the voltage stability limit was tested on a simple system and very interesting results were found.