An inductive power transfer subsystem for an integrated motor drive is presented in this paper. First, the concept of an integrated motor drive system is overviewed, and its main components are described. Next, the paper is focused on its inductive power transfer subsystem, which includes a magnetically coupled resonant circuit and two-stage energy conversion with an appropriate control method. Simplified complex domain analysis of the magnetically coupled resonant circuit is provided and the applied procedure for its component selection is explained. Furthermore, the prototype of the integrated motor drive system with its control is described. Finally, the prototype based on the gallium nitride field effect transistors (GaN FET) inductive power transfer subsystem is experimentally tested, confirming the feasibility of the concept.

A chart design method for multi-coil resonant wireless power transfer (MC-RWPT) systems is presented in the paper. MC-RWPT system is described by a matrix model, which in combination with the coupling calculation method and after applying the optimization procedure, is used to determine the design charts. First, the transfer efficiency is depicted as a function of the number of applied coils and the relative transfer length. Next, the relations between the rest of the system parameters are identified. The influence of the winding filling factor and the relative air gap between the adjacent coils on the kQ factor are also discussed. The proposed chart design method has been experimentally verified. Representative parameters, voltage / current waveforms and the distribution of RMS currents of the coils of the MC-RWPT system are presented.

Assuming that Soft Magnetic Material is a Complex System and expressing this feature by scaling invariance of the power loss characteristic, the unified model of the temperature dependence of Core Losses in Soft Magnetic Materials Exposed to Nonsinusoidal Flux Waveforms and DC Bias Condition has been constructed. In order to verify this achievement the appropriate measurement data concerning power losses and the all independent variables have been collected. The model parameters have been estimated and the power losses modeling has been performed. Comparison of the experimental values of power losses with their calculated values has showed good agreement.

This paper presents a hybrid switches based on semiconductors and mechanical switches. Devices are dedicated to limitation of adverse effect of capacitive type loads start-up especially in domestic applications, during which high value of inrush current is generated. Two different approaches are studied in the paper, both of them using energy harvesting to operate. The proposed solution combine together several advantages switches, such as: increased lifetime of the mechanical part, small on-state losses, smaller dimensions in comparison to mechanical switches, increased durability on overcurrent states, arc-less switching, or limited switching transients. In presented case solution is adopted as rocker switch of LED light sources.