Long term stability of two 1000 kV voltage dividers

In order to calibrate high voltage d.c. dividers in testing laboratories and HVDC converter substations, a new measurement infrastructure for on-site calibration has recently been established. Two 1000 kV voltage dividers have been built, a stationary reference divider at the SP Technical Research Institute of Sweden, and a wide-band modular HVDC divider for on-site assessment capable also of measuring ripple voltage and protected against damage owing to transients. The two 1000 kV voltage dividers were calibrated and their performance verified in June 2013. The scale factors of the two dividers were determined in this comparison campaign, with a combined expanded uncertainty better than 20 µV/V at 1000 kV for both dividers. The stationary reference divider is based on wire wound…