Comparison between ig Integration and vgs Derivation methods dedicated to fast Short-Circuit 2D-Diagnosis for Wide Band Gap Power Devices

Barazi Yazan (1, 2) , Nicolas C. Rouger (3) , Frédéric Richardeau (3)

1 LAPLACE - LAboratoire PLasma et Conversion d'Energie
2 IRT Saint Exupéry - Institut de Recherche Technologique
3 LAPLACE-CS - Convertisseurs Statiques

This paper presents and compares two original high speed protection circuits, ig integration and vgs derivation methods against Short Circuit (SC) types, Hard Switch Fault (HSF) and Fault Under Load (FUL). Since the gate-drain capacitor Cgd of a power device depends on vds, it can become an original native sensor to monitor the switching operation and so detect unwanted vds transition or absence of vds transition by monitoring only vgs. Using only low-voltage monitoring is an essential step to integrate fast and embedded new detection methods on an ASIC gate driver. This Cgd capacitor plays a major part in the two detection methods. The first method is based on dedicated two-dimension monitoring of the gate charge transferred in a time interval combined with gate voltage monitoring. The second method consists of the reconstruction of the dvgs/dt by means of a capacitive current sensing to provide the vgs derivation combined with the vgs monitoring. Comparison and simulation of the methods based on a C2M0025120D SiC MOSFET device under LTspice™ are made to verify the validity of the methods. In terms of detection speed of the SC, a detection time of 300ns is obtained for both methods. Both methods are easy to design, and to integrate. However, the robustness and the speed of detection trade-off of all these methods will be analyzed and compared relatively to the critical functionalities.

Domaines: Energie électrique; Electronique

Barazi Yazan, Nicolas C. Rouger, Frédéric Richardeau. Comparison between ig Integration and vgs Derivation methods dedicated to fast Short-Circuit 2D-Diagnosis for Wide Band Gap Power Devices. ELECTRIMACS 2019, May 2019, Salerno, Italy. ⟨hal-02180892⟩