METHOD FOR CALIBRATING THE MEASUREMENT ERROR OF INSTRUMENT TRANSFORMERS

摘要

The invention relates to a method for calibrating a measurement error ε_ref of a first measuring transformer (10) connected to a phase (30) of a high-voltage line, said method comprising the following steps: a) establishing the first transformer as a reference transformer (20) and initially establishing that the measurement error ε_ref is zero; b) obtaining a measurement, at an instant of time, of a first voltage value V_ref of the reference transformer (20) for loading conditions; c) at the above-mentioned instant of time, measuring a second voltage value V_med of a second transformer (10) connected to the above-mentioned phase (30), said second transformer (10) operating under predetermined loading conditions; d) calculating a relative measurement error ε of the second transformer (10) in accordance with ε_med = (V_med- V_ref)/ V_ref; [1 ]; e) calculating the absolute measurement error ε of the second transformer (10) in accordance with ε = εmed + ε_ref [2]; f) repeating steps (b) - (e) for a plurality i of second transformers (10); g) assigning values to the measurement error ε_ref of the reference transformer (20) in order to minimise the difference between the absolute measurement error ε of each second transformer (10) and an expected error for each second transformer under its loading conditions.