Analysis of Phase Shielding Method Based on $\Delta\text{-Cr-Y}$ Three-Phase Interleaved LLC Converter

Based on the Δ-Cr-Y three-phase interleaved LLC converter, a series of possible phase shielding methods are proposed, and one of them is analyzed in detail. After the phase shielding operation, the resonant frequency of the converter does not change, which means smooth switching in the field of DC transformers. But in voltage regulation applications, careful design of parameters is required because the gain characteristics of the converter change significantly. After loss analysis and comparison, the efficiency can still be improved at light load due to the reduction in volt-second product, even if the cores cannot be removed from the circuit.