Real-time compensation of instrument transformer dynamics using frequency-domain interpolation techniques

The dynamics of current and voltage transformers often limit the accuracy of measurements in high-voltage power systems. These dynamics may not be well known, but frequency-response data obtained on the instrument transformer may be available for a finite set of frequencies. A compensating digital filter that approximately inverts the instrument transformer´s frequency response is calculated using frequency-domain interpolation techniques. The Power Quality Analyser makes use of the compensating filter technique for improved accuracy of its real-time power quality calculations and analyses