Loss formulas from functions of voltage angles

A NEW APPROACH in the form of remarkably simple formulas for the determination of incremental transmission losses in electric power systems has been advanced by Brownlee.¹ He derived the formulas for the simplest possible transmission system of two generators connected by a single transmission line, and then showed that they were applicable to practical power systems by working out some numerical cases. Brownlee´s formulas are functions of the phase angles of the generator bus voltages, so that their application is restricted to those cases where the phase angles are known, such as a-c network analyzer studies.