Calculation and Analysis for Spectrum Characteristics Parameters of Switching Device for Reduced EMI Generation

Accurately obtaining the spectrum characteristic parameters of switching devices is very significant for reduced electromagnetic interference (EMI) generation on the device switching process. This article proposed the universal analytical waveform (UAW) to equal the interference source in the device switching process, and analyzed its time and frequency-domain characteristic parameters. First, the time-domain equivalent method of UAW is proposed, and all the parameters of UAW are calculated with the switching process of the device. Then, the frequency-domain characteristic parameters of UAW are mathematically derived based on Fourier transform, and obtained the spectrum envelope functions. Subsequently, the experiments of Si IGBT and SiC
mosfet
have been performed to verify the correctness of the UAW, which provides the interference source for EMI prediction of the system where the device is located. Finally, taking SiC
mosfet
as an example, specific solutions to reduce the interference source are discussed, which can be used to diminish the EMI generation of the system where the device is located.