An H5-bridge based laddered CLLC DCX with variable DC-link for PEV charging applications

Speaker:    Mingde Zhou

Time:         14:00-15:00 , Mar. 04

Location:   SIST 1C 101

Host:          Haoyu Wang

Abstract:

Plug-in electric vehicles’ charger is preferred to cover an ultrawide battery voltage range with the vehicle-to-grid capability. Conventional bidirectional resonant dc–dc converters suffer from the contradiction among wide voltage gain range, squeezed dc-link voltage span, and narrow switching frequency band. To solve the issue, a novel H5-bridge-based bidirectional CLLC converter is proposed. By configuring the switch pattern, the H5-bridge can form the modes of single half-bridge, dual half-bridge, half full-bridge, and dual full-bridge, respectively. Correspondingly, six gain curves can be derived. Combined with the variable dc-link framework, the converter constrains the switching frequency in the vicinity of the resonant frequency with optimal efficiency. The converter achieves an ultrawide battery voltage range with a squeezed dc-link span. A bidirectionally synchronous rectification method is proposed to improve the efficiency further. To verify the proposed concept, a 1-kW rated prototype with a 320–420 V dc link is built and tested. It validates the battery voltage 55–420 V for charging and 230–420 V for discharging. Zero-voltage turn- on and zero-current turn- off are achieved in the rectifying MOSFETs. The prototype exhibits 98.04% peak efficiency and good overall efficiency performance.

Bio:

Mingde Zhou (Student Member, IEEE) received the B.S. degree in automation from Shandong University, Jinan, China, in 2019. He is currently working toward the Ph.D. degree in electrical engineering with the School of Information Science and Technology, ShanghaiTech University, Shanghai, China.