This paper proposes an enhanced area product (Ap) method aided by simulation for accurate Ap estimation across all operating cases, combined with a low-cost ferrite-core height customization to optimize Ap using commercially available cores in Triple-Phase-Shift (TPS) modulated Dual-Active-Bridge (DAB) converters with ultra-wide voltage range (500–1500 V) and high power (30 kW) for EV charger applications. Designing a high-frequency isolation transformer under such wide voltage variation and power is challenging. The enhanced Ap method incorporates precise volt-second and RMS current data from PLECS simulations, capturing the unique two- and three-level TPS waveforms across the full operating range—unlike conventional approaches relying on fixed waveform factors that introduce uncertainties. A 15 mm core height reduction achieves a 22% decrease in transformer height, 17% reduction in core losses, and 25% increase in power density, ensuring optimized Ap. To meet the high Ap requirement, a parallel-primary/series-secondary dual-core configuration was adopted. A hardware prototype with Litz-wire windings at 140 kHz validated feasibility of the proposed methodology.
