Online Junction Temperature Monitoring Using Intelligent Gate Drive for SiC Power Devices

Journal Article · 04 November 2018 · IEEE Transactions on Power Electronics

DOI: https://doi.org/10.1109/TPEL.2018.2879511 · OSTI ID:1558511

Zhang, Zheyu  ^[1]; Dyer, Jacob ^[1]; Wu, Xuanlyu  ^[2]; Wang, Fei ^[1]; Costinett, Daniel ^[1]; Tolbert, Leon M.  ^[1]; Blalock, Benjamin J. ^[1]

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1. Univ. of Tennessee, Knoxville, TN (United States)
2. Northwestern Polytechnical Univ., Xi’an (China)

Junction temperature is a prime design/operation parameter, as well as, a main indicator of device's health condition for power electronics converters. Compared to its silicon (Si) counterparts, it is more critical for silicon carbide (SiC) devices due to the reliability concern determined by the immaturity of new material and packaging. This paper presents a practical implementation using an intelligent gate drive for online junction temperature monitoring of SiC devices based on turn-off delay time as the thermo-sensitive electrical parameter. First, the sensitivity of turn-off delay time on the junction temperature for fast switching SiC devices is analyzed. A gate impedance regulation assist circuit is proposed to enhance the sensitivity by a factor of 60 and approach 736 ps/°C tested in the case study with little penalty on the power conversion performance. Next, an online monitoring unit based on gate assist circuits is developed to monitor the turn-off delay time in real time with the resolution less than 104 ps. As a result, the micro-controller is capable of “reading” junction temperature during the converter operation. Finally, a SiC-based half-bridge inverter is constructed with an intelligent gate drive consisting of the gate impedance regulation circuit and online turn-off delay time monitoring unit. Experimental results demonstrate the feasibility and accuracy of the proposed approach.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; National Science Foundation (NSF)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1558511
• Journal Information: IEEE Transactions on Power Electronics, Journal Name: IEEE Transactions on Power Electronics Journal Issue: 8 Vol. 34; ISSN 0885-8993
• Publisher: IEEECopyright Statement
• Country of Publication: United States
• Language: English