Abstract—Wide band gap (WBG) devices, like silicon carbide (SiC) MOSFET has gradually replaced the traditional silicon counterpart due to their advantages of high operating temperature and fast switching speed. Paralleling operations of SiC MOSFETs are unavoidable in high power applications in order to meet the system current requirement. However, parasitics mismatches among different paralleling devices would cause current unbalance issues, which would reduce the system reliability and maximum current capability. Thus, to achieve current balancing operation, this paper proposes a
solution of using multi-level active gate driver, where the dynamic current sharing during turn-on and turn-off processes are achieved by adjusting the delays, intermediate turn-on and turn-off voltages. The static current sharing is maintained by regulating the static turn-on gate voltage, where the on-state resistance mismatch between different devices can be
compensated. A double pulse test setup with two different SiC MOSFETs is built to emulate the scenario of worst case application with large differences of threshold voltage and on-state resistance. The experimental results demonstrate that the proposed active gate driver can achieve both dynamic and static current sharing operations for SiC MOSFETs with paralleling operation. Moreover, the system control diagram is discussed. Simulation studies are conducted to achieve closed-loop control of the paralleled SiC MOSFETs with the aid of the active gate driver approach.
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Comprehensive Investigations on Paralleling Operation of SiC MOSFETs based on Subcircuit Model in MATLAB/SIMULINK
Wide band gap (WBG) devices have been widely applied in industrial applications owning to their advantages of low switching loss, low on-stage voltage drop, and high operating temperature. Paralleling operation of power devices/modules is attractive due to its cost-effective and high power characteristics. In applications require very high current capability, paralleling operation of off-the-shelf power devices/modules becomes the only choice. However, current balancing operation of individual power device/module becomes difficult due to the differences of circuit parasitics. To investigate the device/module and circuit parasitics influences on the current sharing performance, in this article, a subcircuit model was built in MATLAB. Comprehensive comparisons and analysis are performed, which can provide guidance for engineers when designing the system with paralleling devices/modules. Moreover, the solutions to achieve current balancing operating are proposed with the aid of active gate driver. Experiment results are presented and analyzed to validate the effectiveness of current sharing solutions.
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- Award ID(s):
- 1939144
- NSF-PAR ID:
- 10317621
- Date Published:
- Journal Name:
- IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia)
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/WiPDAAsia51810.2021.9656101
