Analysis of the influencing factors for the 500 kV DC voltage reference divider used for on-site calibration

High-voltage dc (HVDC) reference divider is essential for on-site calibration of HVDC measuring systems. In this paper the effect of the change of temperature, electromagnetic environment of converter station and other factors on the ratio accuracy of reference divider is analyzed. The influence of high voltage connection cables, which apply high voltage to the reference divider and calibrated divider, on the uncertainty of the reference divider is also analyzed, with the application of ANSYS software. The simulation results show that the influence of high-voltage connection cables on the ratio error of the designed 500kV reference divider is less than 1×10^-5. In addition, a kind of anti-interference method is proposed for the output signal of reference divider. That is, single-grounded twin shielding cable can effectively reduce common mode interference.