Investigation of Power System Blackouts and Prevention Strategies

University of Zululand, Department of Engineering, Richards Bay, South Africa

Abstract

Power system blackouts remain a significant grid reliability threat, often resulting from cascading failures triggered by faults, operational errors, extreme weather conditions or cyberattacks. This study investigated the mechanism of power system blackouts and evaluated practical prevention strategies aimed at improving power system resilience. Historically significant blackout events were analysed to identify common failure patterns and key lessons for modern grid operation. A simulation-based approach was adopted using an IEEE 9-bus test system on DigSilent Powerfactory to analyse cascading failures under generator outage conditions. The effectiveness of load reduction and battery energy storage systems (BESS) was assessed using frequency and voltage stability metrics. The simulation results showed that the loss of generator 3, representing approximately 26.6 % of total generation capacity, resulted in voltage and frequency instability that met the study’s blackout criteria. Under the load reduction scenario, voltage was restored with a minimum voltage of 0.9515 p.u. and frequency nadir of 49.747 Hz, whereas BESS support achieved faster voltage recovery (4s versus 6s) while maintaining full load supply. These findings demonstrate that BESS provides more effective blackout mitigation strategy than conventional load reduction and can significantly enhance power system resilience.