Publication: Condition assessment of OLTC using duval triangle and static winding resistance test
Date
2012
Authors
Khiar M.S.A.
Thayoob Y.H.Md.
Ghazali Y.Z.Y.
Ghani S.A.
Chairul I.S.
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Journal ISSN
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Abstract
On Load Tap Changer (OLTC) failure occurs is due to the insulation degradation and contacts failure inside it. Other than that, contacts wear influences the OLTC performances. The worn contacts will cause hotspots in the OLTC tank and cause the insulating oil to degrade faster. As a result, this will lead to the damage of complete transformer unit. Thus, the research work that has been carried out applied the Dissolved Gas Analysis (DGA) via latest Duval Triangle method during the diagnosis of OLTC at the first stage to provide early indication of OLTC's breakdown. The Static Winding Resistance Test is then applied at the second stage to figure out any increase of contact resistances for all phases. The capability of Static Winding Resistance Test in order to provide any sign of bad contacts in fixed condition can be done by comparing two different conditions which are before and after maintenance. � 2012 IEEE.
Description
Keywords
Contact resistance , Dissolved Gas Analysis (DGA) , Duval Triangle Method , OLTC , Static Winding Resistance Test , Contact resistance , Degradation , Optimization , Bad contact , Condition assessments , Dissolved gas analysis , Duval Triangle Method , Hotspots , Insulation degradation , OLTC , On-load tap changers , Winding resistances , Engineering research