A New Control Method for an On-Board Charger for Electric Vehicles Operating in a Split-Phase System

This article introduces a novel control method for an on-board charger (OBC) operating within a split-phase system, which is commonly used in the North American Free Trade Agreement (NAFTA) region, including the United States, Canada, and Mexico. Previous research has not extensively explored control methods for split-phase systems. In response, this article proposes a discontinuous pulsewidth modulation-minimum (DPWM-MIN) approach, which significantly improves efficiency compared to the conventional sinusoidal pulsewidth modulation (SPWM) method. The proposed DPWM-MIN method demonstrates the ability to manage grid conditions when unbalanced loads are present. A comprehensive comparison between SPWM and DPWM-MIN is conducted, focusing on current ripple, switching loss, and core loss analysis. Experimental results from a 7.68-kW OBC prototype are presented to validate the effectiveness of the proposed method. The new control method achieves a peak efficiency of 98%, which is 1% higher than the conventional method. Other performance metrics, such as total harmonic distortion (THD) and the ability to handle unbalanced currents, remain similar to those of the conventional approach.