The influence of CVT parameters on the harmonic transmission characteristics

In order to solve the larger harmonic measurement errors of capacitor voltage transformer (CVT), this paper puts forward a new method of Y-Δ equivalent conversion and cascaded transfer function combining with Bode diagram to study the transmission characteristics of harmonic component for CVT. Simulation work based on MATLAB of the influence of the key circuit parameters on the harmonic transmission characteristics has been presented. Experiment results have also been provided to verify the method. The simulation results show that the Bode diagram of low frequency region presents a band-pass characteristic and is barely influenced by the CVT parameter, while measurement error in high frequency region is much larger due to the existence of peak and trough in the Bode diagram. Simulation results show that the stray capacitance of compensation reactor and primary winding to ground stray capacitance of CVT has great effects on the harmonic transmission characteristics. More circuit parameters is discussed in the simulation model, and the conclusion has strong reference significance on the engineering of the harmonic wave and CVT parameter optimization.