This paper presents a detailed analysis of the safety of human bodies in the electromagnetic field generated by inductive power transfer (IPT) systems designed for kitchen appliances. Comparisons of basic and reference limit values of various safety standards are investigated through theoretical circuit analysis and extensive simulation studies. Simulation models of human bodies along with an IPT system for kitchen appliances are established to reveal the effect of the electromagnetic field on the human body. Corresponding experiments are conducted via constructing a configuration of the designed IPT system and simulating the standing position. Both experimental and analytical results indicate that it is easier to fulfill international safety standards by increasing the operating frequency of the IPT system for kitchen appliances, and hence, the safety of human bodies can be effectively improved.

The magnetic coupling resonant wireless power transfer (MCR-WPT) system is considered to be the most promising wireless power transfer (WPT) method because of its considerable transmission power, high transmission efficiency, and acceptable transmission distance. For achieving magnetic concentration, magnetic cores made of magnetic materials are usually added to MCR-WPT systems to enhance the coupling performance. However, with the rapid progress of WPT technology, the traditional magnetic materials gradually become the bottleneck that restricts the system power density enhancement. In order to meet the electromagnetic characteristics requirements of WPT systems, high-performance Mn-Zn and Ni-Zn ferrites, amorphous, nanocrystalline, and metamaterials have been developed rapidly in recent years. This paper introduces an extensive review of the magnetic materials of WPT systems, concluding with the state-of-the-art WPT technology and the development and application of high-performance magnetic materials. In addition, this study offers an exclusive reference to researchers and engineers who are interested in learning about the technology and highlights critical issues to be addressed. Finally, the potential challenges and opportunities of WPT magnetic materials are presented, and the future development directions of the technology are foreseen and discussed.

In the design of inductive power transfer (IPT) systems for multi-load applications, the versatility of the coupling structure and the choice of parameter values are crucial due to the diversity of load appliance types and operating conditions. In this paper, based on the features of various coupling structures, the equivalent circuit models of four topologies, namely single-input single-output (SISO), single-input multiple-output (SIMO), multiple-input single-output (MISO) and multiple-input multiple-output (MIMO), are established, from which general transfer characteristics are obtained and analyzed. Based on the series–series (S/S) compensation topology, a set of design principles for IPT circuits satisfying various output requirements in a multi-load environment is presented. Moreover, a control strategy to address the impedance matching issue and to facilitate communication between the primary and secondary sides is proposed. The proposed control strategy is experimentally validated.