EEC 348 ELECTRICAL TRANSMISSION AND DISTRIBUTION Exam 2026

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EEC 348: Second Semester Examination for EEC348 Electrical Transmission and Distribution, College of Technology, University of Buea, June 2026, instructor Dr. MEGAM Elie, two hours. Exercise 1 (22 marks): Part A, seven lecture-recall questions on energy-source requirements, electrical network topologies, ENEO network voltage levels, three-phase and high-voltage transmission rationale, substation types, substation elements, and overhead-line description/parameters; Part B, a three-phase line design problem (deliver 190.5 MVA at 220 kV over 63 km with active losses capped at 2.5% of rated power) requiring current per phase, resistance per phase, conductor diameter, and cross-section. Exercise 2 (18 marks): Part A, a GMD/GMR composite-conductor inductance problem for a single-phase line with three go-conductors and two return-conductors at specified spacings; Part B, equivalent hollow-conductor diameter and per-conductor inductance for a two-conductor single-phase line. Problem: Skin Effect (30 marks) -- deriving and applying the effective-cross-section formula Se=pi*delta*(2r-delta) to compare skin thickness, effective area, 50Hz resistance, and Joule losses per km across three conductor-bundling configurations (1x1200mm2, 2x600mm2, 3x400mm2) carrying the same total current, with a concluding discussion of cable cross-section choice.