Stray Inductance Extraction of Multi-Chip Power Module Based on Finite Element Method

It is of great significance to extract the stray inductace of multi-chip power module in establishing a wideband model of power module and DC circuit breaker. A FZ600R12KS4 IGBT module is opened to obtain the internal architecture and the dimensions, and a three dimensional finite element model is established. Current distribution and magnetic flux density is obtained, the stray inductance under different frequencies is calculated by parameter sweep method. A double pulse testing circuit is established to validate the accuracy of the extracted stray inductance. It is shown that the extracted stray inductance by finite element method agrees well with the result by the recommended double pulse experiment. The stray inductance calculated by the falling edge of voltage waveform is not recommended. The extracted stray inductance by finite element method, the recommended double pulse experiment and using falling edge of voltage waveform has little difference from the recommended value of the technical information. The effectiveness of extracting stray inductance of power module by finite element method is demonstrated.