AC Saturation Measurement Method for Inductor Cores

Abstract

Saturation of common-mode chokes (CMCs) in high-power and wide-frequency band applications leads to elevated electromagnetic-interference levels that negatively impact the primary system and nearby devices. However, detecting such CMC saturation is often complex, time-consuming, and costly. This letter presents a method for detecting core saturation by introducing a high-frequency (HF) signal alongside the operational frequencies, including the fundamental switching signal and its harmonics, of a high-power system. To validate the concept, the technique is tested in a controlled environment using an HF detection signal combined with low-frequency saturating current. Experimental results confirm the method’s feasibility, and recommendations for practical implementation are provided.