Calibration of electronic current transformer with analog signal output
The performance of electronic transformer (ET) directly influences power measurement accuracy, of which output mode is quite different from that of electromagnetic transformers. Thus, conventional calibration method is not suitable for testing ET. This paper starts with the definition of ration error and phase error by IEC standard; analyzes problems in the existing calibration methods and then innovatively puts forward employing standard current transformer (CT), precise shunt and oscilloscope to measure ratio and phase error of ET with analog signal output at power frequency and high frequency (1kHz). Moreover, the data were compared and verified by two methods; the results were satisfied. Finally, the uncertainty was evaluated.