Intelligent analysis of voltage stability enhancement in radial distribution networks considering distributed generation and composite load modeling

This paper presents an intelligent analytical framework for enhancing voltage stability in radial distribution networks through optimal distributed generation (DG) placement and composite load modeling. A novel voltage stability index (VSI) is formulated to identify weak buses, while a fuzzy inference system integrates VSI, power-loss reduction, and feeder distance to determine the most suitable DG location. The optimal DG capacity is derived using a quadratic curve-fitting method that minimizes real-power losses. The proposed approach is validated on the IEEE 10-bus test system using MATLAB/PSAT simulations. Results reveal that placing a Type-I DG of approximately 2.6 MW at Bus 10 increases the minimum bus voltage from 0.895 p.u. to 0.971 p.u., reduces total real-power losses by 64.2%, and improves the voltage stability margin by 41.7% compared to the base case. The fuzzy–analytical hybrid approach demonstrates robust performance under composite load conditions and provides an interpretable, computationally efficient strategy for planning DG integration in modern distribution networks.