This paper details the optimization of inductive power transfer (IPT) coil systems with respect to efficiency η and area-related power density α as required in electric vehicle applications. Based on analytical calculations and finite-element models, which are discussed and experimentally verified in detail, generally valid design guidelines for high-power IPT systems are derived, and the η-α-Pareto optimization of a scaled 5kW prototype system is presented. Experiments demonstrate a dc-to-dc conversion efficiency of more than 96.5% at a power density of 1.47kW/dm ² with coils of 210mm diameter/52mm air gap, including the losses in the resonant capacitors and the power converter. Field measurements validate the predicted stray field with a calculation error of less than 10%.

EMC simulations are an indispensable tool to analyze EMC noise propagation in power converters and to assess the best filtering options. In this paper, we first show how to set up EMC simulations of power converters and then we demonstrate their use on the example of an industrial AC motor drive. Broadband models of key power converter components are reviewed and combined into a circuit model of the complete power converter setup enabling detailed EMC analysis. The approach is demonstrated by analyzing the conducted noise emissions of a 75 kW power converter driving a 45 kW motor. Based on the simulations, the critical impedances, the dominant noise propagation, and the most efficient filter component and location within the system are identified. For the analyzed system, maxima of EMC noise are caused by resonances of the long motor cable and can be accurately predicted as functions of type, length, and layout of the motor cable. The common-mode noise at the LISN is shown to have a dominant contribution caused by magnetic coupling between the noisy motor side and the AC input side of the drive. All the predictions are validated by measurements and highlight the benefit of simulation-based EMC analysis and filter design.

A model of magnetic components is presented which includes saturation and static hysteresis and covers a wide frequency range. A dedicated setup measures the B-H curves for extraction of the model parameters and for model validation. The magnetic model is then represented as a spice circuit and is used in transient system simulations of power converters. Simulations and measurements of core losses and the filter performance of common mode chokes are discussed.

This paper reports on a strongly physics-based minimal circuit model for polycrystalline cores, such as ferrites, including dimensional resonance (DR). The models and main properties of DR and hysteresis are recalled, a circuit model is described that incorporates the various phenomena, and it is mentioned how its parameters are extracted by broadband linear response and low-frequency nonlinear measurements. Finally, the simulations are validated with measurements for a specific example. The model turns out to predict accurately the magnetic behavior in the high-frequency nonlinear region.