Research on Proximity Effect in Measuring Error of Active Electronic Voltage Transformers

The principles of the active electronic voltage transformer (EVT) are introduced, and the mechanism of how a proximity electric field can influence the measuring of errors is analyzed from the perspective of the sensor section of the EVT. The error effects of a three-phase proximity electric field, proximal wall, and proximal high-voltage (HV) test equipment on active EVTs are simulated according to actual operation conditions in the laboratory and at a substation site. The theory and simulated analysis indicate that the disparity in practical environmental conditions, which influences the proximity electric field, is a significant reason that active EVTs exhibit excessive errors at substation sites. The error measurement of a three-phase proximity electric field experiment in the laboratory verifies the analysis results. Finally, the principles of selecting materials for capacitive voltage dividers and rationalization proposals for error calibration are given.