Extraction of Junction Temperature of SiC MOSFET Module Based on Turn-On dIDS/dt

Abstract

In this paper, a method of extracting the junction temperature based on the turn-on current switching rate (dIDS/dt) of silicon carbide (SiC) metal-oxide semiconductor field effect transistors (MOSFETs) is proposed. The temperature dependence of dIDS/dt is analyzed theoretically, and experimentally to show that dIDS/dt increases with the rising junction temperature. In addition, other factors affecting dIDS/dt are also discussed by using the fundamental device physics equations and experiments. The result shows that the increase of the DC-link voltage VDC, the external gate resistance RG-ext, and the decrease of the driving voltage VGG can increase the temperature sensitivity of the dIDS/dt. A PCB (printed circuit board) Rogowski coil measuring circuit based on the fact that the SiC MOSFET chip temperature and dIDS/dt is estimated in a linear way is designed to obtain the junction temperature. The experimental results demonstrate that the proposed junction temperature extracting is effective.

Structure and modelling of four‐layer screen‐returned PCB Rogowski coil with very few turns for high‐bandwidth SiC current measurement

“…The measurement of switch current has always been essential for determination of characteristics [1][2][3], real-time extraction of junction temperature [4], protection and control [5][6][7][8]. However, with silicon carbide (SiC) devices, their fast switching speeds and sensitivities to parasitic parameters have noticeably complicated their current measurements [5,9], which now require a current sensor with an extremely wide bandwidth and a high-noise immunity.…”