The calibration of the GIS inductive voltage transformer with rated voltage 400 / √3 kV, frequencies 50 Hz and 60 Hz was requested by GE Grid Solutions and performed in August 2022 at LCOE High Voltage Lab.
Measurement of ratio error and phase displacement of the calibrated voltage transformer from 1.2 kV up to 440 kV, 1.9 times the rated primary voltage of the VT, and both frequencies 50 Hz and 60 Hz, was performed by comparing the measured values of the voltage transformer with the measurements of LCOE Standard Voltage Transformers.
Auxiliary high voltage bushing provided by the manufacturer was used to connect the primary terminal of test object with LCOE HV generator and reference voltage transformers.
LCOE is accredited by ENAC / ILAC to perform calibrations of voltage transformers according to ISO 17025 Std and is the Spanish Designated Institute in the CIPM MRA for high voltage magnitudes and calibrations.
The calibration was carried out following the internal calibration procedure PS3-E5 of LCOE. You can see LCOE accreditation scopes and the Calibration and Measurement Capability (CMC) in the following links:
Technical scope of ISO 17025 accreditation, ENAC
Calibration and Measurement Capability (CMC), CIPM MRA