Design, implementation and verification of gas insulated load break switch at 12 kV voltage level

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: AYŞE BERİL HARMANLI

Danışman: İSMET ERKMEN

Özet:

In this thesis, the engineering design contributions on arc extinguishing method, relevant arc stretching issue, selection of magnet to obtain expected magnetic force, contact structure and magnet selection parameters, insulation medium properties and design effects, operation mechanism, arc modeling and derivation of the design arc modeling formula on 12 kV SF6 gas insulated load break switch is handled. By these contributions of the thesis, the design, prototype manufacturing and verification of the design via testing at an accredited laboratory is investigated. Literature survey is completed related to arc models, arc extinguishing methodology and operation mechanism. As the outcome of this literature survey and the market search the designed load break switch is implemented with an arc extinguishing method based on forcing the arc to diminish via the magnetic force effect of the magnet within contacts. As the operation mechanism, rotation around central axis is applied. The arc extinguishing method and mechanism structure selection are based on the design target of extinguishing the arc in less duration within less separation between contacts compared with other products in market. Arc models starting with Cassie and Mayr models are investigated, and the Cassie model is selected as the most suitable model. Derivation of the Cassie formula and its application on the design is studied. Maxwell and Matlab simulation results are investigated and compared with the mathematical calculations. The SF6 gas parameters as the insulation level are studied and simulated. Contact structure and magnet selection parameters with the spring constant calculations are studied.