The real time measuring of harmonic for three phase network

An instrument for real-time measurement of harmonic and negative-sequence components for three-phase networks is presented. The instrument has six separate analog measuring channels and microtransformers with electronic compensators and the signal prehandling circuits are used to minimize aliasing effects. The instrument uses a prestraightening sync-sample technique for leakage reduction and uses two monolithic microcomputers, as well as an arithmetic processor to enhance its analysis speed. It measures the magnitude and the phase of all harmonics up to the 60th as well as negative components of the fundamental voltage and current.<>