Application of Digital Sampling Method for Voltage Transformer Test Set Calibrations

摘要

An application of digital sampling method for calibration of voltage transformer test sets is described. A digital sampling wattmeter with well-known operating principle was configured and used as a reference comparison bridge. Because of its high accurate ratio and phase error measurement capability, any type of test set regardless of their operating voltage ranges could be calibrated. In this paper, the accuracy of ratio error and phase displacement measurements of the sampling bridge is analyzed for nominal voltages with amplitude and phase differences up to 2% and 2crad, respectively. Additionally, a simple automation method in generation and adjustment of ratio and phase error values is also described.