SIST Researchers Propose E-Vehicle Advanced Power Electronic Converter

ON2018-11-14TAG: ShanghaiTech UniversityCATEGORY: Published Research

Recently, School of Information Science and Technology Assistant Professor Wang Haoyu’s research group proposed a highly efficient LLC resonant topology for plug-in electric vehicle charging applications. Their work, “A Five-Switch Bridge Based Reconfigurable LLC Converter for Deeply-Depleted PEV Charging Applications,” was recently published in IEEE Transactions on Power Electronics.

This work presents a reconfigurable dual LLC converter based on a five-switch bridge to charge the deeply depleted PEV onboard battery packs. Due to the reconfiguration of the primary-side switch network, two resonant tanks could operate in integrated half-bridge, half-bridge, hybrid bridge, and full-bridge modes. Thus, four operation modes are derived, with their normalized voltage gains scaled to 1:2:3:4, respectively. Those four modes enable a squeezed switching frequency span, which is close to the resonant frequency. Therefore, the efficiency performance over an ultra-wide output voltage range can be optimized. Zero-voltage-switching can be realized in all power MOSFETs over the entire load range. The operating principles, and voltage gains analysis are briefed.

A 1.1 kW-rated prototype converting the 390V input to 100V-420V output, is designed and tested to validate the proof of concept. The prototype demonstrates 97.64% peak efficiency and good efficiency over the full charging range.

All the work was done in ShanghaiTech University. The first author is Li Cheng, a third-year master’s student and the co-author is Shang Ming who earned his master’s degree last year from ShanghaiTech. Wang Haoyu is the corresponding author. The work was supported by Shanghai Sailing Program, ShanghaiTech start-up funding, and the National Natural Science Foundation of China.

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Schematic of the proposed reconfigurable LLC topology

Curves of normalized voltage gain versus normalized fs

Waveforms of mode transition

Cheng Li and Prof Wang in PEARL lab