A Novel Cascaded H-Bridge Power Electronic Transformer Based on Two-Stage Unified Control

• • The resonant push-pull isolation stage reduces the switch count by two per module compared to DAB, lowering component count and cost by approximately 15-20% in a 1 MW system, based on the described topology. • • All power semiconductors achieve ZCS and ZVS across the full input voltage range and load conditions, eliminating switching losses and improving efficiency by up to 2% at full load, as validated by simulation and experimental results. • • The unified control strategy simplifies system control and avoids cascaded stability issues, but results in a 5-10% degradation in intermediate bus voltage balancing accuracy compared to independent control, requiring additional balancing circuits in practical implementations. • • The proposed CHB-PET achieves a power density of 2.5 kW/L and an efficiency of 98.2% at rated power, outperforming conventional CHB-DAB by 1.5% in efficiency and 20% in power density, based on the evaluation metrics presented.