A Relationship for the Reactance Behavior in Voltage-Constrained Power System Components

This paper presents the results of a generalized algebraic statement for the reactance behavior in voltage constrained power system components cited in the single machine-infinite bus (SMIB) and radial power link (RPL) systems according to adopted criteria for the independent variable in these systems. The direct analytical solution to the outstanding problem identifies two separate constraint relations for the sending-end E and receiving-end VR voltages. As a result, a different approach to the stability condition has evolved whereby either of the two equations may constitute an independent function for the on-line voltage stability monitoring in its own right, with the other equation providing for the complete SSSL boundary results. The resulting high-order polynomial equation in VR, e.g., with roots describing X-R-V continuous contours (in-waiting-for-E) is bound to embody roots of singularity states that could not have been observed through equations without the resistance parameter. Whereas the angle based voltage stability functions will require additional interpretations for the stability of lagging power factor loads, the resistance-based indices will give conditions for optimal compensation levels in series capacitance applications as well as conditions for the forbidden inductive or capacitive reactance regions in these applications.