Static Charger Research Articles

Efficient Methodology of the Coil Design for a Dynamic Wireless Charger

Dynamic charging is a promising technology that will increase the use of electric vehicles with reduced battery requirements. Designing this type of system is more complex than for a static charger, and leads to a significantly higher demand of computational resources. First, the complex geometries of the coils do not allow analytical equations to be used, and FE tools must therefore be used instead. However, the Litz wire conductor used in these coils will pose a computational problem if it is not well modelled. The second difficulty is that these systems should be analysed with more potential relative positions between the coils, as misalignment is intrinsic in a dynamic charger. These two complications mean that the design process can greatly benefit from techniques that reduce the time taken to derive the coil parameters. This paper shows the feasibility of using an equivalent layer to model the Litz wire in a dynamic charging application, which significantly reduces the computational time of each iteration up to 20 times. As a consequence, the complete design process is faster and accurate. For this demonstration, we illustrate the design for a dynamic charger of a remote control car.

Adaptive wireless power transfer in mobile ad hoc networks

We investigate the interesting impact of mobility on the problem of efficient wireless power transfer in ad hoc networks. We consider a set of mobile agents (consuming energy to perform certain sensing and communication tasks), and a single static charger (with finite energy) which can recharge the agents when they get in its range. In particular, we focus on the problem of efficiently computing the appropriate range of the charger with the goal of prolonging the network lifetime. We first demonstrate (under the realistic assumption of fixed energy supplies) the limitations of any fixed charging range and, therefore, the need for (and power of) a dynamic selection of the charging range, by adapting to the behavior of the mobile agents which is revealed in an online manner. We investigate the complexity of optimizing the selection of such an adaptive charging range, by showing that two simplified offline optimization problems (closely related to the online one) are NP-hard. To effectively address the involved performance trade-offs, we finally present a variety of adaptive heuristics, assuming different levels of agent information regarding their mobility and energy.

Triboelectrostatic separation of granular plastics mixtures from waste electric and electronic equipment

ABSTRACTThe efficiency of the electrostatic separation of insulating granular mixtures depends on the electric charge carried by the particles. The first objective of this work was to characterize the tribocharging properties of various plastic materials in the composition of waste electric and electronic equipment: polyvinyl chloride (PVC), “high-impact” polystyrene (HIPS), acrylonitrile butadiene styrene (ABS), “high-density” polyethylene (HDPE), polycarbonate (PC), polyamide (PA). Thus, in a first series of experiments, 15 samples composed of binary mixtures of above plastics were initially charged in a fluidized bed device, then separated using a free-fall electrostatic separator. The six plastics could be ordered in a specific triboelectric series: PVC, HIPS, ABS, PEHD, PC, PA. The second objective was to evaluate the efficiency of three tribocharging devices: a static charger, a fluidized bed, and a fan-type device. The triboelectrostatic separation experiments performed with four different binary mixtures (PVC/PA, PC/PA, HIPS/PA, and HIPS/ABS) showed that the fluidized bed is the most effective.

Wireless Charging Technologies: Fundamentals, Standards, and Network Applications

Wireless charging is a technology of transmitting power through an air gap to electrical devices for the purpose of energy replenishment. The recent progress in wireless charging techniques and development of commercial products have provided a promising alternative way to address the energy bottleneck of conventionally portable battery-powered devices. However, the incorporation of wireless charging into the existing wireless communication systems also brings along a series of challenging issues with regard to implementation, scheduling, and power management. In this article, we present a comprehensive overview of wireless charging techniques, the developments in technical standards, and their recent advances in network applications. In particular, with regard to network applications, we review the mobile charger dispatch strategies, static charger scheduling strategies and wireless charger deployment strategies. Additionally, we discuss open issues and challenges in implementing wireless charging technologies. Finally, we envision some practical future network applications of wireless charging.

Tribo-Aero-Electrostatic Separator for Ternary Mixtures of Granular Plastics

This paper presents a comprehensive study of an electrostatic separation device for the recycling of granular plastic materials from waste electrical and electronic equipment (WEEE). The peculiarity of this system is the association of two charging techniques: 1) fluidized bed (dynamic charger) and 2) sliding on inclined plates (static charger)—and two superposed separation units, in order to achieve the selective sorting of a granular mixture composed of three different species of insulating materials. The tests were performed on a mixture of high-density polyethylene (HDPE), polyvinyl chloride (PVC), and polycarbonate (PC). A set of tribocharging experiments was conducted for each material, so that to choose the nature of the walls of the static charger. The analysis of the purity of separated products was performed using an image processing program written in MATLAB. High-purity separation (85%, 95%, and 75% for the PVC, PC, and HDPE products, respectively) was obtained at a recovery rate beyond 80%.

Experimental Investigation of Electrostatic Separators of Plastic Particles using Different Charging Devices

Tribo-electrostatic separation is a clean technology that enables the recycling of plastics contained in granular waste of electric and electronic equipment (WEEE). The granules are first charged using a tribocharging device and then separated in a horizontal intense electric field generated between two vertical electrodes energized with two high-voltage supplies of opposite polarities. The aim of this paper is to perform a comparison between three different tribocharging devices commonly used: the fluidized bed, the static charger, and the tribo-cyclone. The study was carried out using the same granular sample comprising 50% PVC (Polyvinyl chloride) and 50% HDPE (High-density polyethylene) particles of 1–2 mm average granulometric size. In spite that particles acquire higher electric charge using the cyclone device, separation efficiency is better with the fluidized bed device.

An Apparatus for the Measurement of Radiation Intensity Over a Wide Range of Wave Lengths (002-3 Angstrom)

An apparatus for measuring radiation intensity over a wide range of wave lengths is described. This apparatus consists of two parts: (1) a condenser unit to which an ionization chamber is attached, and (2) an improved type of string electrometer, including a static charger. The condenser unit, with the electrometer attached, can be charged to a known potential, after which it is removed and placed with its ionization chamber in the field of radiation which is to be measured. After the chamber has been exposed for a specified length of time, the condenser unit with the attached ionization chamber is again connected with the electrometer and the loss of charge is directly read on the scale. This loss of charge can be converted into r units if the material from which the ionization chamber is constructed and the size of the chamber are properly selected, and if the electrical factors of the instrument are known. Radiation intensities for the range of wave lengths from 0.02 to 3A measured with this instrument are given.