Research on the Capacitor Voltage Transformer Measurement Error under Harmonic Environment

Domestic capacitor voltage transformers (CVT) has more than 30 years of development history, its performance also is more perfect. At present, the most important features of CVT are: high electric strength, insulation margin, reliable operation, reliable damping ferromagnetic resonance, and excellent transient response characteristics. Although CVT has the above advantages, the relevant national standards regulate that capacitor voltage transformer cannot be used for harmonic measurement. When the measured voltage frequency changes or contains harmonic, CVT internal equilibrium will be broken, resulting in the increase of measurement error. Therefore, studying the CVT secondary side output error in the different harmonic conditions, researching error calculation theory and test verification method and seeking for appropriate error reduction method are very important for improving high voltage measurement accuracy in harmonic environment.