This paper presents a comparative study between two AC/DC/DC rectifier topologies applied in electric vehicle (EV) charging systems: the conventional single-phase boost power factor correction (PFC) circuit and the two-phase interleaved boost PFC circuit, both utilizing proportional–integral (PI) controllers. In the context of increasingly distorted power grids—subject to voltage sags, waveform distortions, and harmonic noise—enhancing rectifier topologies to improve charging quality and system stability has become essential. The system models are developed and simulated in the Matlab/Simulink environment to comprehensively evaluate key performance indicators including charging efficiency, total harmonic distortion (THD), power factor (PF), DC bus voltage stability, and dynamic response under varying load conditions or grid voltage disturbances. Simulation results demonstrate that the interleaved boost PFC topology offers superior power quality, with lower THD, power factor values approaching unity, and more stable DC output voltage—even under unfavorable grid conditions. Furthermore, this structure reduces electrical and thermal stress on power components due to current-sharing characteristics between phases. The study therefore affirms that the interleaved boost PFC rectifier is an effective and reliable solution for enhancing the performance and robustness of EV chargers in non-ideal power grid environments.