Design and Implementation of Bi-directional CLLC DC-DC Converter-Rehearsal 

Full bridge of Bi-directional CLLC Resonant DC-DC (BCRDC) converter with an integrated transformer for electric vehicle (EV) applications.
First Harmonic Approximation (FHA) method for calculating the value of C-L-L-C and gain voltage analysis.
Small-signal method for modeling the system to analyze the dynamic performance and design the control system.
Proposed the new close-loop algorithm controller for speeding-up dynamic response.
Synchronous Rectification (SR) is implemented to reduced the conduction losses in the switches.
The simulation software PSIM is used to verify the proposed method.
The result of settle time is reduced that 0.625ms in the proposed algorithm and 1.25ms in conventional algorithm at forward mode, whereas 1.25ms in proposed algorithm and 2.5ms in conventional algorithm at reverse mode.
A 70kHz, 200W prototype is built with a peak conversion efficiency of 95.1% using SR in forward mode. The peak 93.5% in forward mode and 93.1% in reverse mode without SR, respectively.
The result of settle time is reduced that 15ms in the proposed algorithm and 40ms in conventional algorithm at forward mode, whereas 10ms in proposed algorithm and 15ms in conventional algorithm at reverse mode.