A Hybrid Modulation Featuring Two-phase Clamped Discontinuous PWM and Zero Voltage Switching for 99% Efficient DC-Type EV Charger

Junzhong Xu, Thiago Batista Soeiro, Yong Wang, Fei Gao, Houjun Tang, Pavol Bauer

Research output: Contribution to journalArticleScientificpeer-review

10 Citations (Scopus)
6 Downloads (Pure)


Two-stage AC-DC converters are considered as a prominent solution for DC-type electric vehicle (EV) chargers. However, this kind of architecture suffers from high switching losses with large heatsink and DC-link capacitor volume. To relieve this issue, this paper presents a new hybrid modulation for DC-type EV chargers, where a two-phase clamped discontinuous pulse-width-modulation (DPWM) in the front-end circuit is cooperated with the variable frequency triangular-current mode (TCM) zero voltage switching (ZVS) or its simplified implementation, i.e., boundary-ZVS (B-ZVS) strategy, in the back-end circuit. The former can stop the switching actions in the front-end stage during two-thirds of the grid period, while the AC currents are at their highest values, which can yield to the best switching loss reduction and deliver high power factor operation. Besides, TCM-ZVS or B-ZVS modulations can achieve ZVS turn-on action for all semiconductors during all operating range in the DC-DC stage to further reduce the power losses on the semiconductors. With such characteristics, the proposed strategies can reduce the switching losses of the system to the best extent, and thus allow an enhancement of the system power density by improving the power conversion efficiency. The proposed strategy is described, analyzed, validated, and benchmarked in a 5kW SMD SiC MOSFET-based two-stage AC-DC converter. A 99% power efficiency can be achieved with the solution implementing the TCM-ZVS strategy at an output voltage of 400V and rated power.

Original languageEnglish
Article number9645178
Pages (from-to)1454-1465
Number of pages12
JournalIEEE Transactions on Vehicular Technology
Issue number2
Publication statusPublished - 2022

Bibliographical note

Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care
Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.


  • Electric vehicle (EV)
  • two-stage AC-DC converter
  • discontinuous pulse width modulation (DPWM)
  • , zero voltage switching (ZVS)


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