An Online High-Frequency Resonant Current Digitalization Method for CLLC Converters

The resonant current of CLLC converters can reflect its working condition for status monitoring and control. However, due to the high-frequency component in the resonant current, it is hard to digitize and hence rarely to be utilized. In this paper, a high-frequency resonant current digitalization method is proposed to online sample and digitize the resonant current of CLLC converters. The repetition feature of resonant current is leveraged to combine sampling results from several contiguous cycles, and the high time-resolution sampling curve of the resonant current in one cycle can be reconstructed. A fast reconstruction method is applied to realize an online acquisition with less computation burden to the processor. An experimental test is conducted to demonstrate the validation of the proposed method.