سال انتشار: ۱۳۷۶
محل انتشار: دوازدهمین کنفرانس بین المللی برق
تعداد صفحات: ۸
Gharehpetian – Elec. Eng. Department Amirkabir University of Technology, Tehran, Iran
Mohseni – Elec. Eng. Department University of Tehran Tehran, Iran Germany
Moller – Ins. fur Allg. Elektrotechnik und Hochspannungstechnik RWTH Aachen
In order to design the insulation structure of a transformer, the transient voltage stresses to which all subcomponents of the structure will be exposed must be known. The core non-linearities may play a role during the transients. Therefore, this paper studies the magnetic core performance under FT (Fast Transient) and VFT (Very Fast Transient) conditions. In the first part of the paper the concept of the penetration depth is studied by an ana.lyticamethod. In the next parts, the investigations are accomplished based on the measurements on a model winding and on the main HV winding of a three phase transformer. It is shown that for the FT studies the core has no magnetic role and it can be modeled by a metallic hollow cylinder. For VFT studies it is demonstrated that the role of the core can thoroughly be ignored.