High voltage transmission system planning for a southern African regional grid
Authors:   , Ndlela Nomihla Wandile 
Published: October 2022

It is proposed to use highly complex power system controllers to integrate African power grids into super-grids capable of accepting high levels of renewable energy penetration while maintaining power quality, active and reactive power flow, voltage, and power system stability. The proposed super-grid is built with ultra-high voltage direct current (UHVDC) and flexible AC transmission systems (FACTS), as well as dedicated AC and DC interconnectors with intelligent system applications, to create a Smart Integrated African Super-Grid. DC interconnectors will divide the continent's power grid into five substantial asynchronous portions (regions). Asynchronous segments will restrict AC fault propagation across segments while permitting power interchange between various regions of the super-grid, with minimal difficulties for grid code unification or harmonization of regular design regimes across the continent, as each segment retains its autonomy. A Smart African Integrated Electrical Power System Super-Grid powered by these technologies is critical to Africa's long-term economic growth and development; it is built on the foundation of green energy and harnesses over 200GW untapped potential of Africa's clean renewable hydro-electric, solar-PV, and wind power as part of a vast energy mix comprised of conventional and alternating energy resources. The proposed Super-Grid will power Africa's emerging economy and serve its 1.3 billion people by facilitating electricity trading and power exchange between regional power pools and countries. This study focuses on the development of the Southern African Power Pool (SAPP), into a robust Southern Africa regional grid (SARG), and prospects for a Smart Integrated African Super Grid. The Southern African countries have the potential to have a reliable, sustainable, and efficient electrical power grid; thus, the use of renewable energy is strongly encouraged, as is upgrading the existing AC grid, including encouraging power interconnections to exchange power more specifically for long-distance transmission networks when transmitting bulk power using High Voltage Direct Current (HVDC) and installing suitable FACTS controllers to maximize power transfer. Thus, the modernization of the traditional Power Grid into a Smart Grid will enable two-way digital communication technology by providing utilities with real-time, precise data on electricity demand, power outages, and quality of supply. This study develops a load flow model for a robust Southern African Regional Grid, and introduces a number of power interconnections for power exchange in the Southern African Regional Grid, to increase grid reliability, and reduce electrical losses. This load flow analysis was carried out using DIgSILENT PowerFactory. Results obtained from varying the load and observing the generator and transmission lines for different scenarios, using HVDC, and HVDC transmission links with FACTS controllers, are discussed and presented. This study is valuable as we seek to enable all SAPP countries to interchange power more efficiently, especially those who lack access to electricity