An IGBT junction temperature evaluation model for DC interruption application

IGBT is the core component of the hybrid direct current circuit breakers (DCCB), whose junction temperature is the key indicator for evaluating the ability of devices to withstand short-circuit current surges and ultimate breaking capacity. Thus, it is important to evaluate the junction temperature of IGBT under DC interruption application. At present, the main method for evaluating IGBT temperature is combining the finite element method (FEM) simulation and Cauer Thermal Network (CTN) model, which needs a large calculation amount and extracting IGBT physical structure parameters with complicated steps. In this paper, the IGBT model for DC interrupting is built, and a junction temperature prediction model based on a fast Forster-Cauer conversion algorithm is proposed. The IGBT power loss during DC interruption is taken as input, combined with junction temperature evaluation model to realize the rapid acquisition of temperature distribution between the physical layers of IGBT. The © results are shown to verify the feasibility of IGBT junction temperature evaluation model. It’s a kind of simple and fast simulation model without obtaining the detailed physical parameters in advance and suitable for temperature distribution research of IGBT core layers for turn-off transients under the large current surges.