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- Qin, Haihong, et al.
(författare)
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Evaluation and Suppression Method of Turn-off Current Spike for SiC/Si Hybrid Switch
- 2023
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 11, s. 26832-26842
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Tidskriftsartikel (refereegranskat)abstract
- SiC MOSFET/Si IGBT (SiC/Si) hybrid switch usually selects the gate control pattern that SiC MOSFET turns on earlier and turns off later than Si IGBT, with the aim of making the hybrid switch show excellent switching characteristics of SiC MOSFET and reduce switching loss. However, when SiC MOSFET turns off, the fast slew rate of drain source voltage causes the current spike in Si IGBT due to the effects of parasitic capacitance charging and carrier recombination, which will produce additional turn-off loss, thus affecting the overall efficiency and temperature rise of the converter. Based on the double pulse test circuit of SiC/Si hybrid switch, the mathematical model of the turn-off transient process is established. The effects of the remnant carrier recombination degree of Si IGBT, the turn-off speed of SiC MOSFET and the working conditions on the turn-off current spike of hybrid switch are evaluated. Although adjusting these parameters can reduce the turn-off current spike somewhat, additional losses will be introduced. Therefore, a new method to suppress the turn-off current spike is proposed to balance the power loss and current stress.
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2. |
- Qin, Haihong, et al.
(författare)
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Parameters Design and Optimization of SiC MOSFET Driving Circuit with Consideration of Comprehensive Loss and Voltage Stress
- 2023
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Ingår i: Micromachines. - : MDPI AG. - 2072-666X. ; 14:3
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Tidskriftsartikel (refereegranskat)abstract
- In conventional parameters design, the driving circuit is usually simplified as an RLC second-order circuit, and the switching characteristics are optimized by selecting parameters, but the influence of switching characteristics on the driving circuit is not considered. In this paper, the insight mechanism for the gate-source voltage changed by overshoot and ringing caused by the high switching speed of SiC MOSFET is highlighted, and we propose an optimized design method to obtain optimal parameters of the SiC MOSFET driving circuit with consideration of parasitic parameters. Based on the double-pulse circuit, we evaluated the influence of main parameters on the gate-source voltage, including driving voltage, driving resistance, gate parasitic inductance, and stray inductance of the power circuit. A SiC-based boost PFC is constructed and tested. The test results show that the switching loss can be reduced by 7.282 W by using the proposed parameter optimization method, and the over-voltage stress of SiC MOSFET is avoided.
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