This study employs unsteady Computational Fluid Dynamics (CFD) simulations to analyze the aerodynamic characteristics and the complex flow phenomena of dynamic stalls, aiming to uncover the transition in the flow by the addition of Leading-Edge Protuberance (LEP) on the blades of vertical-axis wind turbines. The impact of the vortices generated in the trough and the peak section of the LEP on the growth of the starting vortex greatly influences the dynamic stall phenomenon and its study becomes of utmost importance to design an efficient vertical-axis wind turbine. The detached Eddy Simulation (DES) technique employing a hybrid RANS/LES is used to compare the change in the aerodynamic performance of the wind turbine: with the baseline model (straight blade S1046), the modified model (leading-edge protuberance (LEP) model) to understand the variation in the aerodynamics characteristics, and the influence of vortices shed by the LEP on the evolution of dynamic stall vortices. The counter-rotating vortices result in the transfer of momentum in the lower region of the boundary layer delaying the formation of the starting vortex and subduing the intensity of the dynamic stall vortex.