Modelling a Modified Equivalent Circuit of a Single-Layer, Solenoidal Inductor at High Frequency

In the design of high-power density converters, increasing the switching frequency is one of the main factors to enable the reduction in the required value and size of the passive components. The switching frequency can reach a few MHz in the case of Gallium Nitride devices. At such a high frequency a slight variation in the capacitances and inductances in the converter circuit, can have a considerable effect on its switching behaviour. Therefore, a 3D design of stray elements, such as equivalent series inductance of capacitors and equivalent parallel capacitance of inductors is required to control these effects and improve the converter performance. Also, having both active and passive components integrated with the whole converter will allow us to better control the effects of the parasitic elements and achieve a more optimal switching behavior. In this paper, a Modified Equivalent Circuit (MEC) from the Classic Equivalent Circuit (CEC) has been proposed and is based on physical properties of single-layer solenoid inductor along with a suggested path of the energy transfer between the two adjacent turns of the inductor. Both inductance and capacitance matrices are obtained using magneto-static and electro-static finite element simulations (using MAXWELL). The results of these FEM simulations coupled with the proposed equivalent electric circuit is used to predict the frequency behavior of the component. The model is validated experimentally using an experimental inductor demonstrator.