Power Definitions For Unbalanced Three-Phase Systems Operating Under Sinusoidal Conditions

This paper considers power definitions for unbalanced three-phase power systems operating under sinusoidal conditions. The most well-known power definitions have been analyzed and compared. Based on Fortescue symmetrical components, novel power definitions for three-phase four-wire systems with unbalanced voltages and loads are suggested. To provide the correct calculation of powers for three-phase four-wire systems with unbalanced voltages, the proposed definitions do not use zero sequence voltages and currents calculated for a four-wire system.