A coupling thermal parameter extraction method of Si/SiC hybrid switch

Abstract

The hybrid switch (HyS), composed of Si insulated gate bipolar transistors (IGBTs) and SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) in parallel, offers comparable overall performance to SiC at a significantly lower cost. However, in practical applications, HyS often encounters severe thermal stress imbalances, posing challenges for reliable operation and emphasizing the crucial role of accurately estimating the thermal characteristics of the HyS to enable effective thermal monitoring. In this paper, we first present a novel coupling thermal parameters extraction method of Si/SiC hybrid switch based on a thermal network zoning equivalent strategy. By partitioning the thermal network, we reduce the order of the nodal temperature expression, allowing for the construction of a lower-order thermal model. Subsequently, we establish a constraint relationship between the time constants of the case temperature cooling curve and the thermal parameters, enabling the estimation of RC parameters. Unlike traditional solutions, our method simplifies the parameter identification process and facilitates precise thermal monitoring of the HyS. Experimental results confirm the accuracy and effectiveness of our proposed approach. This research contributes to enhancing the understanding and optimization of thermal behavior in Si/SiC hybrid switch for improved performance and reliability in practical applications.

Keywords

• Si/SiC hybrid switch
• coupling thermal parameters extraction
• thermal network zoning equivalent
• case temperature cooling curve
• the zero-input response method