AC Saturation Measurement Method for Inductor Cores

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