A method for field verification of the precision class of inductive voltage transformers Conference Paper


Authors: Brandao, A.F., Jr.; de Silos, A.C.; Ivanoff, D.; da Silva, I.P.
Title: A method for field verification of the precision class of inductive voltage transformers
Keywords: potential transformers; Mollinger and Gewecke diagram; Shering-Alberti method; current tests; field verification; inductive voltage transformers; no-load loss tests; primary winding dispersion reactance; short circuit tests; winding ohmic resistances tests; winding turns relation
Conference Title: High Voltage Engineering, 1999. Eleventh International Symposium on (Conf. Publ. No. 467)
Volume: 1
ISBN: 0537-9989
Publisher: Unknown  
Date Published: 1999
Start Page: 209
End Page: 212 vol.1
Notes: It is shown here that the precision class of an IVT-inductive voltage transformer-can be verified in the field, using the results obtained in the usual tests of no-load loss and current, short circuit and winding ohmic resistances, performed with common meters. A graphic diagram-the Mollinger and Gewecke diagram-is employed together with the results of an accuracy test previously carried out in order to determine the exact value of the winding turns relation and of the primary winding dispersion reactance. These values are used to calculate phase and magnitude errors, that must obey standards and must lie between definite limits, defined by the precision class of the instrument. Some commercial IVTs were tested in order to check the validation of the procedure. The errors were compared with the ones obtained with the Shering-Alberti method (CA bridge and comparison with standard IVT)
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