Reconfiguration of Uganda’s HV and associated MV network to manage fault levels attached to accelerated power generation

Abstract

The rapid growth of power generation in Uganda has brought forth a pressing concern: the impact of this accelerated generation on fault levels within the high-voltage (HV) and associated medium-voltage (MV) transmission networks. This comprehensive study delves into the intricate dynamics between increased power generation and network stability, aiming to provide a clear understanding of the implications and propose effective mitigation strategies. This research commences by modelling Uganda's existing transmission network in DigSilent Power Factory, establishing baseline fault levels across various network buses. It then introduces short- and long-term load forecasting models, providing insights into the evolving energy landscape, particularly the dynamic relationship between load growth and distributed generation (DG) integration. The core of this study lies in the fault level analysis, unveiling significant increases in fault levels at various network buses due to the addition of power generation plants. Particularly, buses in Lira and Opuyo witness the most substantial increments, necessitating proactive measures for network stability. Notably, Nalubaale/Kira and UETCL Iganga buses, which already feature elevated fault levels, experience further amplifications, raising concerns about their proximity to recommended thresholds. In response to these findings, the study proposes a mitigation strategy involving network reconfiguration and equipment upgrades. The cost-benefit analysis demonstrates that these adjustments should not be viewed as expenses but as investments that result in considerable economic benefits. The mitigation strategies not only enhance the power grid's reliability but also mitigate Energy Not Served (ENS), resulting in additional energy sales. This research underscores the pivotal role of network planning and operation in managing fault levels in a DG-rich environment. It recommends that planners incorporate fault level assessments into grid design and highlights the importance of policy guidelines and investments in real-time monitoring. Furthermore, it suggests avenues for future research to explore advanced fault models and grid modernization initiatives. In conclusion, this study provides valuable insights into the complex interplay between accelerated power generation and fault levels in Uganda's transmission network. It offers practical recommendations and emphasizes the need for a proactive approach to safeguarding the grid's reliability and sustainability.