Behaviors of the Voltage Transducer in Harmonic Measurements and Its Automatic Calibration

The emission of harmonics from power electronic devices causes extra stress of equipment in power systems. Hence, the need of harmonic distortion measurements is increasing. Harmonic measurements in high voltage systems with voltage transducers may cause large errors. In this paper, a calibration method implementing software digital filters and the phase locked loops is presented. With this method, we investigated frequency responses of voltage transducers in two converter station of the Germany railway. These results could also be considered to calibrate voltage transducers before the harmonic measurement.