There are many controversys of non-linear load power definition up to now. The most well known definitions are: (a) Budeanu, (b) Fryze, (c) Kusters and More, (d) IEEE, (e) Sharon, (f) Czarnecki, (g) Shepherd and Zakikhani. This thesis will introduce another new definition to analyze power components of power distribution system. It uses three-axis vector concept to redefine the existing power definition. Finally, computer simulation analysis of AC-DC rectifier will be presented to verify its feasibility.