Technical impact of grid integration of wind power on distribution or sub-transmission networks: A case study for Namibia

Namibia is currently at a stage of integrating Wind Power into the National grid. This paper investigates the technical impact of grid integration of wind power on subtransmission networks in Namibia. Distribution voltage is defined as any voltage below and including 44kV while transmission voltage is voltage levels above 44kV, transmission voltage forms a basis for this study. The authors analyse the performance of a portion of typical Namibian sub-transmission network before and after wind integration by performing standard load flow and short circuit studies in DIgSILENT Power Factory. The impact of wind integration on a network is investigated with respect to: impact on the voltage levels at the point of connection; impact of the size of the wind generator on power losses in the network and fault levels at the buses of the power network. The results reported in the paper are expected to provide a guideline to network planners particularly in Namibia on key technical issues to be considered when connecting a wind farm generator to distribution or subtransmission networks.