The development of equivalent system technique for deriving an energy function reflecting transfer conductances

This paper shows that a well-defined energy function can be developed to re flect the transfer conductances for multi-machine power systems under an as sumption that all transmission lines have uniform R/X ratios. The energy fu nction is derived by introducing a pure reactive equivalent system for the given system. In this study, a static energy function reflecting transfer c onductances is also derived as well as the transient energy function. The p roposed static energy function is applied to voltage stability analysis and tested for various sample systems. The test results show that the accuracy of voltage stability analysis can be considerably improved by reflecting t ransfer conductances into the energy function.