Power Compensation of Shunt Capacitors for Hybrid Multi-Source Systems: Improving Voltage Stability and Reducing Losses

Radial distribution systems provide inexpensive and straightforward interfaces between the power grid and customers. However, these systems frequently experience significant power losses and voltage instability, particularly at buses farther from substations due to insufficient reactive power support. Optimal capacitor placement and sizing are therefore critical. This paper presents a genetic algorithm (GA) approach to solve the capacitor placement problem, aiming to reduce power losses and enhance both voltage profiles and voltage stability. Voltage stability is defined as the ability of the system to maintain acceptable bus voltages under varying load conditions, and the proposed method demonstrates improvement by restoring voltages within ±5% of nominal limits and increasing stability margins. Extensive case studies on IEEE 25, 35, 50, 70, and 120 bus systems confirm the effectiveness of the GA-based method, showing robust performance across different levels of distribution system complexity. Results highlight significant reductions in losses and measurable improvements in voltage stability, thereby enhancing the efficiency and reliability of radial distribution systems.