This work develops a unified MATLAB/Simulink framework to evaluate and directly compare the Ferranti effect in 132-kV overhead lines (OHL) and underground cables (UGC) under identical operating conditions. The study quantifies that underground cables exhibit nearly eight times higher voltage rise and require approximately twenty times greater shunt-reactor compensation than equivalent overhead lines. These findings offer planning and protection engineers a quantitative, technology-specific framework for allocating reactive-power compensation in hybrid OHL-UGC sub-transmission corridors.
