Yuhang Ma, Lisong Wang, Lu Liu, Zhongqiang Hu, Zhiguang Wang, Ming Liu
Press-pack power modules are valued for their reliability and stability, making them indispensable to ensure safe operation of power electronics within smart grids. However, the complex coupling of multiple physical fields in press-pack power modules can present risks to their electrical performance. Accurate measurement of both dc leakage currents and high-frequency switching currents is essential for the comprehensive evaluation of long-term degradation and transient electrical stress in power devices. We proposed a noninvasive dual-mode current sensor based on a wound coil with Co-based amorphous wire core. By sharing a single magnetic core and coil, the sensor exhibits both the giant magneto-impedance (GMI) effect and electromagnetic induction. Integrating the GMI effect for dc to low-frequency measurements with inductive sensing for high-frequency components, the sensor achieves a wide bandwidth from dc to 10 MHz. Compared to single-chip and hybrid current sensors, this design overcame the bandwidth limitations and simplified the sensors. The 10 kHz press-pack fast recovery diode (FRD) was selected for experimental validation due to its accessibility and typical characteristics. The proposed sensor enabled real-time current monitoring, accurately capturing waveform transitions across half-wave rectification, with performance closely matching that of a commercial reference probe. Although the nominal frequency of the FRD is 10 kHz, the associated transient behavior and harmonic content extend into the megahertz range. The dual-mode current sensor accommodates this broadband spectrum, enabling precise waveform reconstruction and comprehensive capture of current transitions.