Contingency Analysis and Voltage Profile Enhancement of High-Voltage Transmission Lines Using Artificial Neural Network A Case Study: On the Ethiopian Power System

Abstract

The power system is an extensive and very sensitive to damage and failures network, especially in the period of outage of transmission lines as well as power-generating units. There has to be a contingency analysis because the sensitivity demands it; a check on the security of the power system upon any outage to ensure the operation remains within safe limits. Unsafe operating conditions may arise from unscheduled outages of lines in interconnected power systems that can propagate throughout the rest of the network. In addition, these types of outages can also further initiate cascading failures that eventually could develop into a total blackout. This paper presents detailed contingency analysis and simulation results for Ethiopian high-voltage transmission networks with Power World Simulator, which gives a deep evaluation on how well the power system performs under different scenarios. The thesis starts with a case that represents normal system conditions, meaning all transmission lines, transformers, and generators are functioning. It then considers three critical line outage cases: the Gefersa to D/Markos line, the Sebeta to Gefersa line, and the Wolkite to Sebeta line. In each of these scenarios, major voltage drops and very bad overloading conditions are exhibited; in particular, when the Sebeta to Gefersa transmission line is outaged, the loading levels reach extremely high levels plus there is a very bad risk of cascading failures. Also, this thesis looks at the inclusion of Distributed Flexible AC Transmission Systems (D-FACTS), which are seen to greatly improve voltage profiles plus stabilize networks. Bus ranking severity: comparison via numerical analysis and Artificial Neural Network (ANN). The voltage profile after insertion of D-FACTS lies within its acceptable range (0.95-1.05p.u. Overall, the findings underscore the urgent need for robust contingency planning and infrastructure improvements to ensure the reliability and safety of the Ethiopian power system.