The paper presents a systematic design method for proportional-resonant controllers used in dynamic voltage restorers (DVR) to manage voltage sags and swells in power systems. The proposed method includes considerations for both current and voltage control loops, demonstrating their effectiveness through simulations and hardware-in-the-loop experiments. Results indicate that the designed system can effectively mitigate single-phase and three-phase voltage sags up to specified levels in under one cycle of grid voltage.