Conductor selection and economic analysis of D.R.congo–guinea±800 kV UHVDC transmission project

Africa is embracing new opportunities featured with industrialization,urbanization and regionalization.Based on co-development of‘Electricity,Mining,Metallurgy,Industry and Trade’and grids interconnection proposed by Global Energy Interconnection Development and Cooperation Organization(GEIDCO),the high-quality hydropower resource of the Congo River can be exploited in large scale under the wide-range interconnected framework of African Energy Interconnection(AEI),forging a new engine for Africa economy.The transmission distance of the Congo River hydropower reaches 6,000 km at its farthest end in North Africa,which brings forth challenges to economics of proposed projects.Under this novel continental energy interconnection scheme in Africa,economics of those projects have not yet been in detail studied.This paper has implemented China’s mature engineering experiences and analytical tools of UHVDC project planning into the AEI structure,through exploring the economic behavior of ultra-long distance UHVDC projects in the scope of conductor selection in the Congo River hydropower transmission for the first time,and has provided concerned parties with a technical and analytical results of their economics comparison.This paper has chosen the D.R.Congo-Guinea±800 kV UHVDC project as a typical example.Its preliminary system planning is introduced and three types of conductor are selected for scheme comparison.Later in this paper,the transmission loss,total investment and equivalent annual cost of the project have been calculated and analyzed.In the final part,sensitivity analysis results of the annual cost to utilization hours,transmission loss,loss tariff and construction cost has been provided.