Apparent power and power factor in unbalanced and distorted systems. Applications in three phase load compensations

Abstract

The apparent power and the derived power factor are  two  of  the  quantities  of  the  biggest  use  and  application  inside    the    Electric    Engineering.    However,    nowadays    it    continues staying the controversy on their definitions and more appropriate meaning in the most general situations in unbalance and distortion, and unequal resistances in the distribution lines. In  the  last  years  they  have  been  distinguished  two  focuses  concerning  the  functional  definitions  of  apparent  power:  the  European approach, more theoretical and better developed, and the  American  approach,  more  practical  focus  but  with  smaller  rigor.   Although   from   the   point   of   view   of   their   practical   application,  the  use  of  a  definition  or  another  doesn't  suppose  important   numeric   differences,   if   present   differ   from   the   conceptual  point  of  view.  This  is  made  notice  in  applications  that    suppose    the    use    of    modern    equipments    of    static    compensation. The apparent power of the European approach in its  conception  only  permits  parallel  compensation,  while  the  apparent  power  of  the  American  approach  admits  the  series-parallel  compensation.  This  paper  introduces  the  definitions  of  apparent   power   of   both   approaches   and   it   establishes   a   discussion   on   its   application   in   the   three-phases   loads   compensation.