Three-phase Frequency Measurement under Non-sinusoidal Conditions Using the Static Reference Frame.

Abstract

The  utilization  of  Clark’s  transformation  in  the  estimation   of   the   power   system   frequency   provides   more   robustness  to  the  classical  single-phase  methods.  One  of  the  advantages   of   this   technique   is   that   extract   the   frequency   information   contained   in   the   three-phase   system.   This   is   particularly  important  when  asymmetric  sag  generates  a  zero  voltage in one of the three phases.