A PCB-Incorporated Inductor Based Filter Design Solution for Differential Mode Noise of 3-Phase SiC-MOSFET Based VSI

Abstract

Electromagnetic emission is a challenging problem for the Wide Band Gap (WBG) device based power electronic converters. The Differential Mode (DM) noise contains switching frequency components and high-frequency noise peaks. High-frequency DM noise peak depends upon the loop inductance of the converter and output capacitance of the switch. Optimization of switching frequency or variable switching frequency could attenuate switching frequency noise and its harmonics only, but not the switching transient noise. Using a passive filter is common for IGBT based VSI, where the high-frequency DM noise peak occurs in the $1MHz$ to $5MHz$ range. However, the high-frequency DM noise peak appears beyond $10MHz $ for SiC-MOSFET based VSI. It requires a high corner frequency, lower inductance, and capacitance of the DM filter. However, getting an inductor with a high Self-Resonating Frequency (SRF) is challenging. This paper proposes a PCB-incorporated inductor based segmented LCLC filter with high SRF value for high-frequency DM noise of SiC-MOSFET based VSI. The filter design is based on mathematical modeling of the DM noise of SiC-MOSFET based VSI. The proposed filter is implemented and verified on a SiC-MOSFET based VSI, driving a $5 kVA$ induction motor at $40 kHz$ switching frequency.

Keywords

• Differential mode (DM) noise
• electromagnetic emission
• filter
• PCB incorporated
• voltage source inverter (VSI)
• WBG