• Gebretsadik Teklay Gebremichael

This paper presents the design of HVDC transmission system and shows why it is preferred over HVAC transmission for power transmission over long distances. The HVDC transmission design presented here originates from Bahir Dar substation in Ethiopia and terminate at Aswan in Egypt. The total length of the transmission line is approximately 2313km. The design involved choice of the most feasible routing. The entire route was subdivided into these sections. A bipolar dc link configuration was chosen with a standard transmission voltage of +/- 800kV to transfer 2000MW power. The most economical solution for the conductor type from the design was ACSR Finch type, four conductors per pole. The conductor size was 846.6 mm2 cross-sectional area and 32.84 mm diameter. The proper size of the smoothing reactor 200 mH was selected. Moreover, the other basic considerations in HVDC like design of line parameters, converter transformer, and harmonic filters were conducted. The designed and modelled transmission line required two converter stations; one at Bahir Dar in Ethiopia and another at Aswan in Egypt. Furthermore, during the conversion of AC to DC or vice versa harmonic contents were generated because of nonlinear loads like rectifiers, but these contents were mitigated by using harmonic filters and smoothing reactors coordinately. This paper also gives the feasibility of converting a double circuit AC line into composite AC-DC transmission line given with the advantage of stability improvement, damping oscillation and reactive power compensation for AC weak buses. Simulation and experimental studies using MATLAB 2015a Simulink model were carried out for the coordinated control as well as independent control of AC and DC power transmissions.

HVDC, HVAC, Converter transformer, Harmonics, Smoothing reactor, Filter.

"DESIGN AND MODELLING OF HVDC LINE FROM BAHIR DAR (ETHIOPIA) TO ASWAN (EGYPT)", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 9, page no.443-453, September-2018, Available :http://www.jetir.org/papers/JETIR1809092.pdf

"DESIGN AND MODELLING OF HVDC LINE FROM BAHIR DAR (ETHIOPIA) TO ASWAN (EGYPT)", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 9, page no. pp443-453, September-2018, Available at : http://www.jetir.org/papers/JETIR1809092.pdf