An Enhanced Pre-Filtering Stage and LL-Esthetically Modifications in DAB Converter/Dual PSM Technique for Robust On-Board Charger Design

The most common factors influencing the performance of on-board electric vehicle (EV) chargers are grid voltage and a diverse loading pattern. Furthermore, the proportion of ripples in charging current affects charger and battery health. To overcome these concerns, a model predictive (MP) hybrid dual phase shift modulation (hy-DPSM) approach is developed. It arrives with both unidirectional and bidirectional conduction angle control. Here, cost functions emerge from the refined phase shift (PS) parameter expressions. This is intended to lower peak current stress while retaining it in zero-voltage switching (ZVS) region. This results in a secured flat efficiency profile with a significant reduction in current ripples throughout a large battery voltage and loading range (maximum to cutoff value). Additionally, a modified pre-filtering stage is proposed to safeguard the active front-end rectifier from grid voltage uncertainties. It is accomplished by integrating a dc offset rejection loop into a conventional second-order sequence filter (SOSF). This provides combined immunity to the presence of lower-order harmonics and dc offset in sensed and conditioned grid voltage. In this regard, a 3.3 kW hardware prototype is designed in the laboratory to validate the proposed control over numerous charging circumstances.