Multi-Objective Optimization of a Toroidal Inductor Considering Parasitic Capacitance

Due to the arrival of wide band-gap semiconductor technology and a consistent trend of increasing power density in power electronics, high-power converters with relatively high operating frequencies in the hundreds of kHz to tens of MHz are more common-place. When designing magnetic components in this frequency range, many challenges come into view. Component performance becomes increasingly reliant on managing high-frequency loss mechanisms and parasitic effects. The parasitic capacitance is often minimized to extend the component’s inductive energy storage behavior to higher frequencies. This paper builds on previous work associated with a multi-objective optimization-based design tool for toroidal power inductors. An analytical, closed-form mathematical method to predict parasitic capacitance in toroidal inductors with single-layer windings is outlined. The calculations are applied as a constraint in a multi-objective optimization paradigm to assess design trade-offs in higher power, high-frequency inductors. The model and assumptions are validated through Finite Element Analysis (FEA), showing good agreement. Observations on model assumptions and accuracy are provided, as well as analysis and discussion on post-optimization results.