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.