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

This paper 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, secondaryside 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 (AFDRC) strategy exhibiting robustness against variations in system parameters is also proposed. Finally, experimental results validate that the hybrid CLLCDAB system, employing the proposed design methodology and control strategy, attains both high system efficiency and ultrafast dynamic response.