Effects of Airgaps on Parasitic Capacitance of Magnetic Components

This article investigates the effects of airgaps between different parts of magnetic cores on the parasitic capacitance of magnetic components, which was excluded by previous research. According to the physical mechanism of the electric field in airgaps, the single-perfect-electric-conductor assumption, which has been widely used in previous research, is improved to mutiperfect-electric-conductor assumption by considering the effects of airgaps on the voltage potential distribution of magnetic components. Furthermore, the improved physics-based analytical model is developed based on the proposed assumption for demonstrating the effects of airgaps on the parasitic capacitance of magnetic components. The analyses are verified by finite-element-method simulations and experimental verifications, which accurately predict the effects of airgaps on the voltage potential distribution and the parasitic capacitance in magnetic components.