Energy flow in electric systems — The VI energy-flow postulate

The conditions which a valid postulated electric-energy flow must satisfy are given and are stated to be insufficient for its unique determination. The commonly used Vi energy-flow postulate is shown by examples to be not generally valid, but by adding a simple term it can be made equally valid with other valid energy-flow postulates. Various examples are given of the application of this corrected energy-flow postulate. On power systems the engineer commonly limits his use of the uncorrected Vi postulate to applications where the correcting term should have a negligible net effect. Various examples of such use are discussed.