
LCOE performs measurement of no-load losses, load losses and sound level on 400 MVA 400/155 kV and 600 MVA 400/230 kV autotransformers for GETRA
18 octubre 2023
LCOE attending 70th Technical Meeting of STL hosted by ZKU in Prague
28 noviembre 2023
Test for accuracy of one capacitive electronic voltage transformer manufactured by GE Grid Solutions France with rated primary voltage 420 / √3 kV and rated frequency 50 Hz has been performed in September 2023 at LCOE High Voltage Lab.
Measurement of ratio error and phase displacement of the electronic voltage transformer was performed for measurement and protection digital outputs. Test for accuracy of the measurement output was performed applying 80 % - 100 % - 120 % of rated primary voltage Upr and test for accuracy of the protection output was performed from 2 % to 190 % Upr reaching a highest voltage level of 460.7 kV.
The test was performed by direct comparison of the readings of the electronics transformer digital outputs with the analogue measurements of two LCOE Standard Voltage Transformers. One inductive Standard voltage transformer was used from 4.8 kV up to 240 kV and the other one was used from 250 kV to reach the maximum voltage level of 460.7 kV applied during the test.


Accuracy results of CEVT 420 kV unit with environmentally friendly gas
The voltage transformer was filling with two different insulating gases SF6 and new environmentally friendly alternative gas developed by GE Grid Solutions France to check the influence of the insulation media in the accuracy results. Auxiliary high voltage bushing provided by the manufacturer was used to connect the primary terminal of test object with LCOE AC high voltage generator and reference voltage transformers.
The test for accuracy was carried out following the technical requirements of new IEC 61869-1:2023 Edition 2.0 2023, IEC 60044-7:1999 and the IEC project document of future IEC 61869-7 Standard.
A high precision comparator bridge was used to compare analogue output of LCOE Standard Transformers with digital outputs of the electronic voltage transformer and synchronization of the measurements was performed according to IEC 61850-9-2 Standard communication protocols.
LCOE is accredited by ENAC / ILAC to perform test for accuracy of voltage transformers according to ISO 17025 Std and is the Spanish Designated Institute in the CIPM MRA for high voltage magnitudes and calibrations.
You can see LCOE accreditation scopes and the Calibration and Measurement Capability (CMC) in the following links:
- Technical scope of ISO 17025 accreditation, ENAC
https://www.enac.es/documents/7020/4e9a3359-acca-49ab-aeb2-f8f4971f2d5c
- Calibration and Measurement Capability (CMC), CIPM MRA

More information about this publication www.lcoe-hv.com
Tomás García tgarcia@ffii.es
Paula Cid paula.cid@ffii.es