Characterization of Harmonic Frequency Response of Capacitive Voltage Transformer

The harmonic frequency response characteristics of CVT are of great significance to the correction of its harmonic measurement error. Based on the basic structure of 500kV capacitive voltage transformer, an equivalent circuit model of industrial frequency and harmonic transmission is constructed, and the amplitude and phase frequency response curves of CVT are given. The influence of harmonic content and harmonic order on fundamental and harmonic frequency characteristics is studied. It is shown that the frequency response curve of CVT is not smooth due to the existence of obvious singular points, and the response characteristics of the frequency near the singular points deteriorate sharply. The order of harmonics and their content have basically no effect on the error transfer characteristics of the fundamental wave. When fundamental and multiple harmonics exist at the primary side at the same time, the influence of multiple harmonics on the ratio difference of each harmonic component can be basically negligible, but there is a certain impact on the diagonal difference.