الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Large buildings and the transport of power both frequently use electric power cables. As the cable itself does, the laying arrangement and sheath bonding have an impact on cable system transients. Large zero-sequence current is not a new phenomenon for cable bus duct systems; the question is what influences its magnitude. It was found that the zero-sequence currents were circulating between different circuits in the cable system and that they were being generated by induction between phases in the same cable route. Zero-sequence circulating currents are particularly problematic because they can occasionally lead to protective relay failure. However, it is not usually understood that systems with numerous cables strung along the same path will produce zero-sequence currents. To acquire realistic cable system impedance/admittance or reasonable simulation results, they must be accurately modelled. It was determined that the zero-sequence currents could be greatly reduced in a twin circuit by symmetrical configuration of the cables. However, in a four-circuit system, no significant reduction could be achieved even by the symmetrical onfiguration. In this thesis, the operation of parallel connections of single core underground cables is examined. The examination is based on power cables arrangement operating in parallel two-circuit and parallel four-circuit with and without the transposition grid. It was found that symmetrical cable arrangement might significantly lower zero-sequence currents. On the other hand, the largest value of the zero sequence currents at asymmetrical configuration. To provide an effective method about reduction of zero sequence current induced in a cable system, several connection scenarios such as the transposition of the cable and sheath and the application of sheath cross bonding are examined. Therefore, in this thesis, this phenomenon will be analyzed and discussed. ATPDraw is used to simulate and analysis these studies.