الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Generator circuit breakers (GenCBs) are located between generators and step-up transformers in power networks and their rating usually range from 100 MVA to 1300 MVA. Because of the potentially high asymmetrical faults levels at relatively low voltage near the terminals of generators, the current interruption requirements of GenCBs are significantly higher than the distribution networks at similar voltages. A few different mathematical circuit breaker models exist and are mostly characterized by experimentally measured parameters to describe the dielectric properties of different phenomena taking place in the breaker opening process. Due to the special nature of GenCBs location between the generator which connected through a cable and step up transformer, this special connection represents a rich transient media which effect on GenCBs TRV and causes of generator winding damaged.In this Thesis, the generator-circuit-breaker (GenCB) is simulated using alternative transient program (ATP-EMTP). The four main stages of the breaker’s operating processes are considered, namely; the closed contacts stage, the arc burning stage, the arc extinguishing stage and the opened contacts stage. Therefore, not only the dynamic conductance during current zero are considered but also the effects of arc voltage on the arcing times are included. The simulation is tested in a representative network and the results are compared with IEEE Generator Circuit Breaker standards. Furthermore, a new mitigation technique is introduced to reduce the transient recovery voltage (TRV) and the rate of rise of re-striking voltage (RRRV) during switching period. The results show that the proposed technique successfully reduces both the TRV and RRRV.Abstract Distributed Generation (DG) is expected to play a key role in the distribution networks. The technologies for DG are based mainly on renewable sources such as photovoltaic, wind turbines, etc. With the growing use of DG, it is very important to study its impact on and its effects on the distribution networks and the industrial distribution network. This thesis interests with the transient voltages generated from switching GenCB of a wind farm connected to a 30-bus distribution network as a DG. Mitigation technique is introduced to reduce the transient recovery voltage (TRV) and the rate of rise of re-striking voltage (RRRV) during switching period. Also, this thesis interests with the transient voltages generated from switching GenCB of a wind farm connected to a 30-bus industrial distribution network. Also, a mitigation technique is introduced to reduce the transient recovery voltage (TRV) and the rate of rise of re-striking voltage (RRRV) during switching period.