Junction temperature monitoring is the basis of high reliability for silicon carbide (SiC) devices since thermal stress is the dominating aging factor. Due to the high switching frequency, conventional thermal-sensitive electrical parameter (TSEP) methods have poor monitoring performance for SiC MOSFETs. The gate current IG has been found as an effective TSEP for SiC MOSFETs. However, the exact relationship between the IG and the junction temperature and its fundamental principle has not yet been fully revealed. Moreover, existing monitoring methods based on the IG are limited to specific devices and require a complex measuring system. In order to solve the problems above, this article puts forward a novel junction temperature monitoring method based on the IG. First, a gate model of SiC MOSFET is proposed. Second, based on this model, an IG-based junction temperature estimation technique is presented. Third, an online measuring method for the IG is proposed. Finally, online experiments validate the proposed method. This novel method has three advantages. First, it can be used in various types of power electronics devices. Second, it can provide decent precision in various working conditions. Third, the measurement circuit required by his method is simple, which adds no additional hardware.

中文翻译：

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基于新型栅极传导模型的SiC MOSFET结温在线监测方法


结温监测是碳化硅 (SiC) 器件高可靠性的基础，因为热应力是主要的老化因素。由于开关频率较高，传统的热敏电参数（TSEP）方法对 SiC MOSFET 的监测性能较差。栅极电流 IG 已被发现是 SiC MOSFET 的有效 TSEP。然而，IG与结温之间的确切关系及其基本原理尚未完全揭示。此外，现有的基于IG的监测方法仅限于特定设备并且需要复杂的测量系统。为了解决上述问题，本文提出了一种基于IG的结温监测方法。首先，提出了SiC MOSFET的栅极模型。其次，基于该模型，提出了一种基于 IG 的结温估计技术。第三，提出了一种IG在线测量方法。最后，在线实验验证了所提出的方法。这种新颖的方法具有三个优点。首先，它可用于各类电力电子装置。其次，它可以在各种工况下提供良好的精度。第三，该方法所需的测量电路简单，无需增加额外的硬件。