Evaluation of Switching Loss Contributed by Parasitic Ringing for Fast Switching Wide Band-Gap Devices
Evaluation of Switching Loss Contributed by Parasitic Ringing for Fast Switching Wide Band-Gap Devices
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DOI：
10.1109/tpel.2018.2883454
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发表时间：
2019-09
影响因子：
6.7
通讯作者：
Zheyu Zhang;Ben Guo;F. Wang
中科院分区：
文献类型：
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作者：
Zheyu Zhang;Ben Guo;F. Wang
在宽带隙(WBG)器件的高速开关过程中，寄生振铃现象十分常见。寄生振铃造成的额外损耗成为一个令人担忧的问题，尤其是对于高开关频率的应用。本文研究了寄生振铃对相桥结构WBG器件开关损耗的影响。推导了考虑功率器件和应用电路中寄生因素的开关损耗解析模型。分别研究了栅极驱动为主和功率环为主的两种开关换流模式，识别了阻尼环引起的开关损耗。结果表明，这部分损耗至多是存储在寄生电路中的能量，无论开关速度和寄生振铃如何，这种能量总是存在的。因此，给定的WBG器件在特定的应用电路中，在较快的开关暂态过程中，抑制更严重的寄生振铃不会带来更高的开关损耗。此外，还研究了寄生和串扰之间的共振引起的额外开关损耗。观察到，在导通瞬变过程中，严重的谐振及其产生的过电压会恶化串扰，导致大的直通电流和过大的开关损耗。理论分析已在1200V/50A碳化硅相桥功率模块的双脉冲试验中得到验证。
Parasitic ringing is commonly observed during the high-speed switching of wide band-gap (WBG) devices. Additional loss contributed by parasitic ringing becomes a concern especially for high switching frequency applications. This paper investigates the effects of parasitic ringing on the switching loss of WBG devices in a phase-leg configuration. An analytical switching loss model considering parasitics in power devices and application circuit is derived. Two switching commutation modes, gate drive dominated mode and power loop dominated mode, are investigated, respectively, and the switching loss induced by damping ringing is identified. It is found that this portion of the loss is at most the energy stored in parasitics, which always exists regardless of the switching speed and parasitic ringing. Therefore, with the given WBG device in the specific application circuit, damping more severe parasitic ringing during faster switching transient would not introduce higher switching loss. Additionally, the extra switching loss induced by resonance among parasitics and crosstalk is investigated. It is observed that severe resonance and its resultant over-voltage during the turn-on transient worsen the crosstalk, causing large shoot-through current and excessive switching loss. The theoretical analysis has been verified by the double pulse test with a 1200-V/50-A SiC-based phase-leg power module.