Technical feasibility study of the use of a statcom and SSSC to optimize the stability of Rwandan electrical grid. Case study: Kigali High Voltage Network

Abstract

The electricity plays a great role in the human activities and in every community. The wide-ranging applications of modern, affordable, reliable, and sustainable electrical energy services can contribute to the poverty eradication and socio-economic development in Rwanda. The Rwandan electrical grid is similar to the most of worldwide countries. It is composed of generation power plants, substations and load that are interconnected by transmission and distribution lines at different voltage levels. The Government of the Republic of Rwanda has initiated different national targets in order to expand the grid with 556MW generation capacity and 100% electricity access by 2024 [1]. The grid will thus become larger and robust to satisfy the highly increasing number of future electricity consumers. Unfortunately, there is a risk that the electric grid will face instability problems along with the amplified power losses from outages and power services delivery to electricity users, especially in high load centers, including Kigali City and industrial areas. It is crucial to plan and execute the future electric infrastructures which can operate at their capacity limits to satisfy both load and socio-environmental requirements. This performance can be achieved by the use of FACTS based technology to improve the network stability and power transfer capabilities. This study finds out an efficient way to build a resilient electrical grid which has the capability to control the voltages and damp the transients on high voltage buses in Kigali region after the occurrence of an electric disturbance by using FACTS controllers “Static Synchronous Compensator (STATCOM)” and “Static Synchronous Series compensator (SSSC)”. In order to reach the expected network performance, the Rwandan high voltage network and past network disturbances have been assessed and the electrical quantities which will be required to control the future network stability have been identified with FACTS Controllers. Furthermore, the future network with FACTS controllers is simulated by using Simulink in order to check the systems behavior by creating disturbances on the different power supplies. At the end, the results have been interpreted and compared to display the stability improvement.