808 / 2022-03-31 23:30:36

Research on harmonic measurement based on reverse correction algorithm of CVT circuit model

capacitor voltage transformer；,harmonic measurement,inversion calculation,stray capacitance,amplitude-frequency characteristics,inversion calculation

The capacitor voltage transformer can accurately measure the 50Hz fundamental frequency voltage. However, The transformation ratio of CVT varies greatly at different frequencies. Then the voltage transfer ratio of CVT in 50Hz fundamental frequency cannot accurately reflect this change, resulting in the harmonic component error of secondary side voltage. In the conventional correction method, harmonic components of CVT secondary side is corrected by reverse coefficient which obtained from the CVT voltage amplitude-frequency response curve. However, this method cannot correct the harmonic components on the secondary side, because the voltage transfer ratio of CVT will be affected by the operating environment. In this paper, a circuit model is established to characterize the voltage transfer ratio of CVT, and an inverse numerical solution method is designed based on this model to dynamically correct the harmonic components of the secondary side voltage.