Abstract

The integration of renewable energy sources into modern power systems has necessitated the development of advanced fault detection and protection mechanisms to ensure system stability and reliability. This research presents the modelling, simulation, and analysis of a fault detection and protection system for high-voltage transmission lines integrated with hybrid renewable energy sources, including wind and solar energy. The study focuses on fault detection, isolation, and relay coordination to enhance the resilience of transmission networks while mitigating power disruptions caused by various fault scenarios. The study investigated fault occurrences at different locations along the transmission line, including the sending end, receiving end, intermediate points, and renewable energy connection nodes. Faults were simulated at 25 km, 50 km, and 75 km from the source, with varying fault resistances. Key parameters such as voltage at fault points, current surges, relay operation time, sensitivity, coverage area, and system stability were evaluated. Advanced signal processing techniques, including wavelet transform analysis, were employed to assess system behaviour during fault conditions, ensuring accurate fault detection and isolation. Results indicated that the Intermediate Point Configuration provided the most balanced approach, offering comprehensive fault coverage, optimal isolation, and minimal system disruption. The impact of different fault types, including Lineto-Ground (LG), Line-to-Line-to-Ground (LLG), and Three-Phase (LLL), was analysed, revealing that three-phase faults caused the most severe disturbances, including voltage collapse and high fault currents. Relay operations were incorporated to isolate faulty sections of the network promptly, ensuring minimal disruption to the overall system. The results demonstrated that relay coordination was effective, with primary relays tripping first, followed by backup relays when necessary. The study also highlighted challenges posed by high-resistance faults and faults at distant locations, which require more sensitive detection techniques. Plots of voltage and current profiles at detection points provided a visual representation of the system's dynamic behaviour under fault conditions. The research concludes that adopting the Intermediate Point Configuration enhances the reliability of high-voltage transmission systems, particularly in networks incorporating renewable energy sources. The findings contribute to the development of improved fault d