Steady-state power flow theory for two-bus transmission systems relates sending-end and receiving-end complex power to the line's ABCD two-port parameters, expressing real and reactive power as functions of voltage magnitudes, the power (phase) angle between them, and the line impedance angle. For a predominantly reactive short line, real power transfer reduces to the classical power-angle equation (P = VsVr sin δ / X), while reactive power transfer depends on the voltage magnitude difference; these relationships underpin reactive power compensation theory (shunt/series, static and rotating) used to control voltage profile and increase transfer capacity. This is a core topic within power system analysis, a subfield of electrical power engineering concerned with steady-state and transient behavior of interconnected generation, transmission, and load.
Steady-state power flow theory for two-bus transmission systems relates sending-end and receiving-end complex power to the line's ABCD two-port parameters, expressing real and reactive power as funct…