There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

A method and apparatus for providing power to e.g., a chargeable device via a radio frequency link. In one aspect, a method of providing power to a chargeable device via radio frequency link comprises generating a substantially un-modulated signal. The method further comprises radiating a substantially un-modulated radio frequency (RF) signal to the chargeable device via a transmit antenna based on the substantially un-modulated signal. The method further comprises powering or charging the chargeable device with power delivered by the substantially un-modulated RF signal.

Method and apparatus for delivering energy to an electrical or electronic device via a wireless link

A method and system for providing power to a chargeable device via radio frequency link are provided. In one aspect, a method of providing power to a chargeable device via radio frequency link comprises generating a substantially unmodulated signal. The method further comprises radiating a substantially unmodulated radio frequency (RP) signal to the chargeable device via a transmit antenna based on the substantially unmodulated signal. The method further comprises powering or charging the chargeable device with power delivered by the substantially unmodulated RF signal.

Method and system for powering an electronic device via a wireless link

Tuning and gain control as described for magnetic power systems, including different ways to change the characteristic of transmission and reception.

Tuning and Gain Control in Electro-Magnetic power systems

hysteresis in magnetism (electromagnetism)

The tolerances and limitations in design and manufacturing of both electrical motors and inverters lead to parasitic resistances in the phases. Therefore, the phase resistances are asymmetric, which causes an asymmetry among the phase currents and a resulting increase in torque ripple. This paper proposes a novel scheme for torque ripple minimization using online estimation of unbalanced stator resistances of a permanent-magnet synchronous motor. The identifiability of the stator resistances in a nonlinear model is investigated by employing a sensitivity analysis. The phase resistances are estimated by recursive least squares in the rotating reference frame in real time. Using the estimated resistances, torque ripple reduction is achieved by a compensation scheme in the stationary reference frame. The effectiveness of the proposed scheme is verified in both simulation and test-bench experiments. Results with and without consideration of magnetic saturation are compared.

Torque Ripple Minimization Using Online Estimation of the Stator Resistances With Consideration of Magnetic Saturation

This paper presents a novel lamination concept for transverse flux machines. The advantage of this concept is that the elements can be easily plugged together. The basic principle can be applied to several transverse flux machine topologies like reluctance type as well as permanent magnet ones with surface mounted and flux collecting topologies. Transverse flux machines are optimal suitable for direct drive applications because of their very high torque density. Their speed range matches the required speed range of electrical vehicles' wheels. The provided torque of the transverse flux machine enables fast acceleration. This publication deals with two concepts of transverse flux machines for application in electrical vehicles. The first concept contains a permanent magnet excited transverse flux machine, the second a transverse flux reluctance machine. The two concepts are compared considering torque density and applicability to electrical vehicles based on a finite element method simulation. Therefore the requirements to the traction drive are derived from desired characteristic values of the electrical vehicle.

Laminated circumferential transverse flux machines - lamination concept and applicability to electrical vehicles

This paper presents a power unit for use in the primary side of 3 kW rated inductive charging system. The objective is the design of 3 kW rated primary sides which are compatible to 20 kW rated secondary side receiving units inside electric vehicles. The motivation arises from the consideration that 3 kW and 20 kW charging stations should be kept compatible. Compatible especially in the way that vehicles with 20 kW rated receiving units should be able to use 3 kW charging stations. The basis for the design of the 3 kW system is a series-compensated secondary receiving coil without an additional DC/DC-converter stage between a B4 rectifier and battery with a rated power of 20 kW. The absence of a DC/DC stage allows lower weight and installation space in the vehicle, but the possibility for impedance matching is missing. The system behavior is investigated analytically, so that all currents and voltages, as well as the reactive power in both compensation networks can be calculated depending on the given systems parameter, such as the inductance of the secondary coil, the coupling factor, the operation frequency and the transferred power. It is shown that the operation point with the lowest reactive power, and thus least losses in the coils and compensation capacitors, strongly depends on the design of the receiving unit. Since the receiving unit is designed for a transferred power of 20 kW, an operation with 3 kW will result in a significantly lower efficiency. Therefore a solution is presented, to shift the ideal operation point of the secondary side system from 20 kW to a much lower value. That way, the 3 kW system is able to operate very close to the shifted ideal operation point.

Design of a 3 kW primary power supply unit for inductive charging systems optimized for the compatibility to receiving units with 20 kw rated power

This paper presents a new analytical model for high-torque and low-speed transverse flux machines with flux collecting permanent magnet type. The model is developed based on approximating the permeance in the air gap between rotor and stator using quasi-flux tubes with boundaries determined by straight lines and semicircular segments. Three kinds of produced torques are achieved analytically and the results are compared to the three dimensional finite element simulation results.

Transverse flux machine for direct drive robots: modelling and analysis

PM Transverse Flux Machines (PMTFMs) can achieve higher torque densities than conventional PM Longitudinal Flux Machines (PMLFMs). Unfortunately, a general problem of PMTFMs is their high cogging torque in comparison to the average torque. Because of this, a new optimization method for reducing cogging will be introduced in this paper. It uses discrete skewing of a segmented stator. The results are based on FEM investigations and validated by measurements at a prototype.

Nejila Parspour

Papers

Torque Ripple Minimization Using Online Estimation of the Stator Resistances With Consideration of Magnetic Saturation

Laminated circumferential transverse flux machines - lamination concept and applicability to electrical vehicles

Design of a 3 kW primary power supply unit for inductive charging systems optimized for the compatibility to receiving units with 20 kw rated power

Transverse flux machine for direct drive robots: modelling and analysis

Reducing the cogging torque of PM Transverse Flux Machines by discrete skewing of a segmented stator