Optimized Design and Fast-Dynamic Control for ISOP-Connected Hybrid CLLC-DAB System With Partial Power Processing Property

This article presents new design and control approaches for an input-series-output-parallel (ISOP) connected hybrid converter with partial power processing (PPP) capabilities, which comprises a
CLLC
converter and a dual-active-bridge (DAB). In this hybrid
CLLC
-DAB configuration, secondary-side bridges are shared between
CLLC
and DAB topologies to minimize the number of utilized switches. Incorporating the high efficiency of
CLLC
with the exceptional control flexibility of DAB, the hybrid configuration transfers the main power through
CLLC
while enabling DAB to handle partial power flow. The power distribution between
CLLC
and DAB is optimized, considering system efficiency, dynamic response, etc. Based on the resulting power ratio, system parameters are also optimized, including considerations for soft-switching of all switches in a wide load range, output power capacity, component tolerances, and overall efficiency. Furthermore, the output voltage can be accurately regulated by manipulating the phase shift angle of DAB. To enhance the system's transient performance in scenarios involving varying loads and input voltages, an adaptive fast dynamic response control strategy exhibiting robustness against variations in system parameters is also proposed. Finally, experimental results validate that the hybrid
CLLC
-DAB system, employing the proposed design methodology and control strategy, attains both high system efficiency and ultrafast dynamic response.