Investigation on peak reverse recovery current for junction temperature estimation of FWD

A good knowledge of junction temperature of high voltage power modules is of great significance for thermal management, lifetime prediction and condition monitoring. Power modules usually incorporate multi IGBT chips and FWD chips. Investigations about junction temperature estimation of IGBT are sufficient, while research about that of FWD is not sufficient with the problems of low sensitivity, invasive implement and unclear theoretical analysis. To address these issues, this paper investigates the peak reverse recovery current and presents a corresponding extraction circuit. Experiments are conducted to validate the established peak reverse recovery current model and the feasibility of the designed peak current detector. The results manifest the superiority of peak reverse recovery current on junction temperature estimation for its good linearity, high sensitivity and non-invasive.