Development of an In-Situ Detection Mechanism for Common-Mode Choke Saturation

The saturation of the common mode chokes (CMCs) in the electromagnetic interference (EMI) filters can impair filter performance, increase EMI issues and reduce efficiency. Detecting saturation in operational conditions presents a significant challenge. Therefore, this paper proposes a method for detecting choke saturation using a three-winding configuration. One winding creates core saturation through the application of DC current, while another introduces high-frequency signals for detection by the third winding. The change in the detected signal indicates saturation. Experimental data validate the proposed detection mechanism, providing a complete understanding of its effectiveness in operating conditions.