Noninvasive Current Distribution Sensing in Press Pack Power Electronic Devices Through Few-Measurement Magnetic Field Analysis

Press pack power devices serve as critical components in various high-power applications. However, the closed structure of these devices poses challenges in sensing their internal current distribution. This letter addresses this issue by proposing a noninvasive current distribution sensing method based on magnetic field analysis. By strategically placing a limited number of magnetic field sensors near the devices, the proposed method enables the estimation of various forms of nonuniform current distribution. After developing a custom four-point magnetic field measurement setup based on Hall sensors, the current distribution measurement of a commercial insulate gate bipolar transistor (IGBT) under different pressure excursion conditions was performed. Experimental results demonstrate the effectiveness and reliability of the proposed method.