Losses in power systems networks: Development of a generalized loss formula

A generalized loss formula (GLF) is developed for the system losses around an operating point. It is a quasi-oscillatory approximation of the exact losses by having the same first and approximately the same second derivatives at the operating point, with respect to three sets of variables: generator powers P_g, generator voltage magnitudes V_g, and transformer tap settings t. The numerical results obtained from two test systems demonstrate that the error in the losses given by the GLF, in comparison to the exact losses from a load flow calculation, is relatively small.