A Novel IGBT Junction Temperature Detection Based on High-Frequency Model of Inductor Element

Accurate online junction temperature detection of high-power insulated gate bipolar transistor (IGBT) modules is necessary for the health management system of key equipment. The voltage rise time ( $t_{\mathrm {rv}}$ ) is a good temperature sensitive electrical parameter (TSEP), which is of great significance for its accurate online extraction. In this article, a novel IGBT junction temperature detection based on the high-frequency (HF) model of inductor element is proposed. First, the equivalent model of the inductor element in the application circuit at HF is demonstrated. Second, based on the HF model of the inductor element, it is proposed and verified that $t_{\mathrm {rv}}$ in the IGBT turn-off process is consistent with the HF current pulse signal on the inductor element at HF, that is, $t_{\mathrm {rv}}$ can be indirectly obtained by extracting the HF current pulse signal. Finally, the feasibility for voltage rise time extraction and junction temperature detection through HF isolation coil is verified by experiments and simulations. The research work in this article is helpful to the online junction temperature detection and has certain theoretical significance and practical engineering value.