Methodologies for electromagnetic field modeling for computer aided analysis of multi-domain physical interactions

Several methodologies are presented in this work to facilitate the modeling of electromagnetic fields in the context of multi-domain physical interactions. Among the challenges for computer aided analysis of electromagnetic problems in interaction with other physical phenomena are the largely different temporal and spatial scales that may occur and the task of maintaining accuracy and computational efficiency in the implementation of boundary conditions for time-varying media. First, we present a methodology for the phenomenological modeling of passive intermodulation generation in metallic contacts due to electron tunneling. The methodology provides for the development of passive intermodulation source models that are compatible with general-purpose electromagnetic and non-linear network analysis-oriented circuit simulators. The derived model allows for an investigation of the impact of surface roughness and skin effect on the levels and frequency dependence of passive intermodulation interference. Thus, the model is intended to enhance the understanding of the passive intermodulation source due to electron tunneling in metallic contacts. The second methodology presented is a Lagrangian approach for increasing the accuracy of the finite difference time domain method for modeling wave propagation in geometries involving curved and moving boundaries. This methodology provides for the definition of an equivalent electromagnetic boundary value problem over a domain with fixed boundaries. A modified time-dependent operator is derived for the Lagrangian formulation, operating on a modified set of Maxwell's equations on a reference domain. This method relaxes spatial oversampling requirement and achieves high accuracy and computational efficiency. The third methodology provides for an efficient analysis of problems with widely separated time scales. We propose the application of the method of multi-time partial differential equations to the numerical solution of one-dimensional electromagnetic wave interactions involving highly disparate temporal variations in both excitation and time-varying media properties and boundary conditions. The temporal oversampling requirement is relaxed by introducing multiple time scales for quasi-periodic functions and, upon solution of the multivariate partial differential equation, we recover a solution to the univariate problem

Design of magnetic-resonant wireless power transfer links realized with two coils: Comparison of solutions

A novel approach for the rigorous design of magnetic resonant wireless power transfer links is introduced. We show how, starting from two coupled inductors and making use of general network theory, it is possible to derive analytic rules for designing the source and load terminations which provide the maximum power transfer efficiency or maximize the received power. We also show that, by adding suitable matching networks to two coupled inductors we can realize a wireless link acting as a 1:n transformer and having the all required tunable reactive elements on the primary side. The proposed topology greatly simplifies the design, since only an inductive coil and a fixed capacitance are required on the secondary side; in addition, when tuning is required due to coils misalignment or to link distance variation, it can be attained by acting on the transmitter side without the need for a feedback communication through the link. Moreover, when the load resistance is designed for maximum output power, its value is fixed and does not depend on the coupling. A numerical and experimental verification of the proposed approach is also presented

A system for dynamic inductive power supply of electric vehicles on the road

A Moving Field Inductive Power Transfer (MFIPT) system for wireless inductive power supply of electric vehicles on the road is described. To minimize losses only those primary coils located below the secondary coil of a vehicle are excited. The dynamics, the power balance of the MFIPT system, and the costs for the implementation of the system are discussed

Rigorous network modeling of magnetic-resonant wireless power transfer

Magnetic-resonant wireless power transfer (MRWPT) has been typically realized by using systems of coupled resonators. In this paper, we introduce a rigorous network modeling of the wireless channel and we introduce several viable alternatives for achieving efficient MRWPT. Ideally, the wireless channel should realize a 1:n transformer; we implement such transformer by using immittance inverters. Examples illustrate the proposed network modeling of the magnetic-resonant wireless power channel

The basic cell operating regimes for wireless Power Transfer of Electric Vehicles

In this work we concentrate on the two possible regimes at which wireless power transfer can be attained. One regime allows to maximize either the power on the load or the efficiency, at a given fixed frequency, by changing the load value. Another regime keeps a fixed value for the load and, for a relatively wide variations of the coupling coefficient, attains fixed efficiency and power transfer by selecting an appropriate working frequency. These two operating regimes are rigorously introduced, relative solutions are analytically expressed and illustrated via numerical simulations

Conditions for a Load-Independent Operating Regime in Resonant Inductive WPT

This paper provides a rigorous theoretical formulation to obtain an inductive resonant wireless power transfer (WPT) link with load-independent output voltage or current. This is a crucial working condition for wireless battery recharging, where there is no deterministic knowledge of load variation with respect to the battery charging level. The ideal lossless and the realistic lossy configurations are considered for both voltage- and current-excited WPT links. The link transfer matrix (ABCD matrix) is used to determine the operating frequencies where a load-independent output voltage or current can be obtained. It is shown that in the lossy cases that an almost load-independent behavior can be achieved, provided that the load resistance lies in a suitable range and analytical conditions on the load resistance value have been derived. The analytical relationships obtained by this theory are validated by means of both circuit simulation and experimental data at 13.56 MHz

Europe and the future for WPT: European contributions to wireless power transfer technology

Summarization: This article presents European-based contributions for wireless power transmission (WPT), related to applications ranging from future Internet of Things (IoT) and fifth-generation (5G) systems to high-power electric vehicle charging. The contributors are all members of a European consortium on WPT, COST Action IC1301. WPT is the driving technology that will enable the next stage in the current consumer electronics revolution, including batteryless sensors, passive RF identification (RFID), passive wireless sensors, the IoT, and machine-to-machine solutions. The article discusses the latest developments in research by some of the members of this group.Presented on: IEEE Microwave Magazin