Method of determination of three-phase voltage asymmetry of fundamental frequency and ultraharmonics

Abstract

The new method of digital determination of symmetric phase-sequence system of three-phase electric voltages is presented. It uses the next operations: tuning multiple three frequency of measuring of instantaneous values to fundamental frequency of network voltage; analog-digital transformation of instantaneous values of three networks voltages and memorized it; selection of codes that contain the sought after symmetric phase-sequence; selection of codes of voltage of fundamental frequency. A method differs in simplicity and exactness.