The external fields in the proximity of electric vehicle (EV) wireless power transfer (WPT) systems requiring high power may exceed the limits of international safety guidelines. This study presents dosimetric results of an 85 kHz WPT system for electric vehicles. A WPT system for charging EVs is designed and dosimetry for the system is evaluated for various exposure scenarios: a human body in front of the WPT system without shielding, with shielding, with alignment and misalignment between transmitter and receiver, and with a metal plate on the system for vehicle mimic floor pan. The minimum accessible distances in compliance are investigated for various transmitting powers. The maximum allowable transmitting power are also investigated with the limits of international safety guidelines and the dosimetric results.

Capacitive power transfer (CPT) system can be employed for wireless charging of drone applications. However, in the CPT system, cross-coupling capacitance caused by coupling of the two pairs of plates on different sides, which do not form the main capacitance must be considered. Designs that do not properly consider the cross-coupling capacitance can cause decrease in the efficiency of the system. In this article, we propose a separate circular capacitive coupler for the CPT system. To reduce the cross-coupling capacitance in drone applications, the plates on the same side are separated. The circuit model of the coupler is presented; it considers a total of six coupling capacitances. For maximum power transfer efficiency, impedance of the receiver is considered to determine the parameter value of the LC resonance. Through simulation and measurement, we verified that the proposed separated circular coupler can reduce the cross-coupling capacitance. The plate-to-plate power transfer efficiency is maintained at 89.4% with 100-W output power.

Damper bars are often used in high output salient pole synchronous motor (SM) rotors for motor starting and stabilization of performance. Several cases of broken damper bars in the rotor of SMs that lead to motor starting failure and/or forced outage have recently been reported. However, detection of damper bar failures is difficult, since the damper bars are active only under the starting or load transients. Damper bar testing in the field currently relies on off-line visual inspection, and there is no means available for detecting failures on-line. In this paper, a new method for detecting damper bar failures based on the analysis of airgap search coil measurements under the starting transient is proposed. Since airgap search coils are being increasingly installed in large SMs for detecting field winding short circuits, the proposed method can be implemented without additional hardware. The effectiveness of the proposed method is verified with 2 dimensional finite element analysis and experimental testing on a custom-built 30 kW salient pole SM under controlled fault conditions. It is shown that the proposed method can provide reliable and sensitive detection of broken damper bars whenever the motor is started at low additional cost. The off-line single phase rotation test is also shown to provide reliable monitoring of damper bar condition.

As the number of electric vehicles (EV) increases, the number of EV chargers also increases. Charging infrastructure will be built into our close environment. Because of this, the assessment of the electromagnetic field exposure generated from the charger is an important issue. This paper valuates the electromagnetic field exposure of six EV chargers. To assess the level of exposure of EV chargers, the electromagnetic fields from six chargers were measured and analyzed. In addition, measured electromagnetic field exposure levels were evaluated against ICNIRP guidelines. Higher electromagnetic fields were measured with standard chargers than with fast chargers. For the fast charger in the charging state, the magnetic field increased with the charging current. Electromagnetic field exposures for all six chargers did not exceed standard limits. The results of the assessment of the electromagnetic field exposure of the six EV chargers will contribute to the establishment of standards for the evaluation of the electromagnetic field exposure of the EV chargers in the future.

This paper has applied a simple model (H2CrO4 + Aliquat 336 ↔ complex) to the mass transfer mechanism of Cr(VI) with Aliquat 336 in a batch-type, supported liquid membrane module. Concentrations at pH 3 are as follows: 0.019 kmol/m3 ≤ Aliquat 336 ≤ 0.035 kmol/m3 and 20 g/m3 ≤ Cr (VI) ≤ 500 g/m3. The measured values of forward- and backward-reaction rate constants between Cr(VI) and Aliquat 336 were used to simulate the model with the mass conservation equation and associated boundary conditions. Comparison between the experimental and simulated facilitated factors of Cr(VI) transport led to classification of reaction regions.