Optimized Load Shedding for Voltage Resilience in Ethiopia's Power Grid

Abstract

This study deals with the essential operational challenges of voltage instability in the Northwest Ethiopian transmission network (NETN), which is a rapidly growing energy demand. An intelligent voltage load-shedding framework, Particle Swarm Optimization, was used for the multi-objective function under contingency scenarios. The proposed method, tested on NETN, comprising 15 buses, 15 lines, two generators, and three external grids, was used to analyze the grid behavior under significant load escalation (50% and 75% increase). The results indicated severe voltage drops at critical buses, notably Metema and Gondar (Metema’s voltage declined from 0.978 p.u. to 0.8638 p.u. at 75% overload). The proposed algorithm combines voltage sensitivity indices with dynamic load-shedding logic to determine the exact place & magnitude of real power changes. PSO-based optimization simultaneously minimizes active power curtailment while maximizing voltage profile recovery. Upon activation, the strategy restored bus voltages to secure levels (Metema up to 0.9538 p.u.) with precise bus-specific shedding of real power. This method effectively and rapidly transitions the system from an emergency to a normal state with minimal load loss. In contrast to traditional approaches, this comprehensive method explores feasibility in near real-time and guarantees system-wide coordination, providing a cost-effective solution for enhancing reliability in developing power systems across various uncertainty and stress conditions. These findings provide an innovative and practical foundation for enhancing the voltage stability.