Power Transformer Immune to Geomagnetically Induced Currents

Summary, in English

Geomagnetically induced currents (GICs) flow mainly through power lines, earthed transformers and earth itself. The near DC currents may cause half-cycle saturation of transformers, possibly causing relay misoperation, increased reactive power demand and damage to transformers. This paper describes a patented idea to make a transformer immune to GIC using compensation windings in each phase. A compensation winding has one third of the turns of the main winding it protects and the three windings are connected in series between neutral point and earth. Time simulations demonstrate that the principle is effective for single-phase transformers, which is the transformer type most sensitive to GIC. It is also shown that the function is affected neither by active and reactive load current nor by high GIC levels. GIC immunity is of particular interest for key transformers, as in large power plants, at the power system periphery, where GIC levels are in general higher.

• Författare: Olof Samuelsson
• Avdelning/ar: Industriell elektroteknik och automation
• Publiceringsår: 2013
• Språk: Engelska
• Publikation/Tidskrift/Serie: Power and Energy Society General Meeting (PES), 2013 IEEE
• Länkar: http://dx.doi.org/10.1109/PESMG.2013.6672596
• Dokumenttyp: Konferensbidrag
• Förlag: IEEE - Institute of Electrical and Electronics Engineers Inc.
• Ämne: Other Electrical Engineering, Electronic Engineering, Information Engineering
• Nyckelord: compensation geomagnetism power transformers transformer windings
• Conference name: IEEE Power & Energy Society General Meeting, 2013
• Conference date: 2013-06-21 - 2013-07-25
• Conference place: Vancouver, Canada
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1944-9925