Search results for "efficiency."
showing 10 items of 1362 documents
Wireless battery chargers for portable applications: Design and test of a high-efficiency power receiver
2013
In this study, the authors present a 5 W wireless battery charger for handheld devices. Efficiency-related issues are addressed. A power receiver architecture which improves power conversion efficiency is proposed. Design hints are provided for further applications. Comparison with a conventional architecture is provided as well. Laboratory prototypes of both the proposed and the conventional architectures have been realised. Both prototypes are tested by using the same power transmitter to perform a valuable comparison. As shown by the experimental results, in the receiver side power conversion efficiency is increased up to 99% thanks to the proposed solution.
Efficiency optimization in bi-directional inductive power transfer systems
2015
Inductive Power Transfer (IPT) allows to wirelessly supply electronic devices. Thus, it is a very smart technique of battery charging for electric vehicles. In a parking area scenario, IPT is a proper method aiming at the energy transfer from the vehicle battery to the electric grid too. Bi-Directional Inductive Power Transfer (BDIPT) Systems are an attractive solution for the automotive market. Due to the great relevance of the energy saving problem, the goal of an efficiency maximization is researched by the energy market. In this paper, an in-depth investigation of the power efficiency in BDIPT systems is carried out, aiming at the optimum efficiency.
An over-the-distance wireless battery charger based on RF energy harvesting
2017
An RF powered receiver silicon IC (integrated circuit) for RF energy harvesting is presented as wireless battery charger. This includes an RF-to-DC energy converter specifically designed with a sensitivity of -18.8 dBm and an energy conversion efficiency of â¼45% at 900 MHz with a transmitting power of 0.5 W in free space. Experimental results concerned with remotely battery charging using a complete prototype working in realistic scenarios will be shown.
Sizing of ICE and Lithium-ion battery for series hybrid vehicle over life cycle with battery aging
2013
This paper presents a method to evaluate the volume and weight of the internal combustion engine (ICE) and lithium-ion battery for a series hybrid vehicle that allows to minimize the mean consumption over system life. Individual driving cycles of the car over a total distance of 100 000 km are simulated. The ICE and battery dimensions are approximated; the fuel consumption is evaluated using a general approach. Lithium-ion battery is described including capacity fading and the energy split between ICE and battery system is evaluated using an heuristic approach. Results show a decrease of mean fuel consumption down to 5.1 L/100km.
Wireless battery charging: E-bike application
2013
Nowadays, Inductive Power Transfer (IPT) represents a widely investigated issue with respect to modern battery charging methods, by providing a wireless solution. IPT is applied across a large variety of applications, from Watt to kWatt power levels. Although IPT features great benefits in terms of safety and comfort, the most significant drawback consists of a relatively poor power conversion efficiency. In this paper, a 100W wireless charging equipment for E-bikes which improves efficiency is proposed. Complete magnetic structure design, as well as transmitter and receiver efficient architectures, are deeply exposed. The efficiency of the designed solution is shown by simulation results.
Multi Architecture Optimization of a Hybrid Electric Vehicle Using Object-Oriented Programming
2017
This article presents an energetic macroscopic representation multi-architecture model for hybrid vehicles using object-oriented programming. This approach is successfully used to evaluate the power performance and fuel consumption of different vehicles on different driving cycles. An optimization of power source sizing (ICE, EM and Battery) and system control, based on simulation results, is carried. Different architectures are compared for given cycles and optimization of hybrid architecture will also be possible.
Control subsystem design for wireless power transfer
2014
Recently, the wireless power transfer has been increasingly employed. Particularly for the electric vehicles, the wireless solution is attractive for contactless battery charging, based on the Inductive Power Transfer (IPT). In this paper, a 150W prototype for IPT-based battery charging is presented and design criteria are reported. In addition to the power stage analysis, a proper control strategy is proposed. Simulation and experimental results are shown. The proposed control method aims at regulating the load current against variations in the magnetic coupling, so that the required amount of power can be supplied despite of unexpected decreases in the coupling efficiency.
Robust Transmit Beamforming for Underlay D2D Communications on Multiple Channels
2020
Underlay device-to-device (D2D) communications lead to improvement in spectral efficiency by simultaneously allowing direct communication between the users and the existing cellular transmission. However, most works in resource allocation for D2D communication have considered single antenna transmission and with a focus on perfect channel state information (CSI). This work formulates a robust transmit beamforming design problem for maximizing the aggregate rate of all D2D pairs and cellular users (CUs). Assuming complex Gaussian distributed CSI error, our formulation guarantees probabilistically a signal to interference plus noise ratio (SINR) above a specified threshold. In addition, we al…
Synthesis and photovoltaic performance of the porphyrin based sensitizers with 2H-[1,2,3]triazolo[4,5-c]pyridine and benzotriazole as auxiliary accep…
2017
Abstract Two novel zinc porphyrin dyes containing either benzotriazole or 2 H -[1,2,3]triazolo[4,5- c ]pyridine as auxiliary acceptors, respectively, were synthesized for dye-sensitized solar cells. These two auxiliary acceptors were firstly applied into porphyrin based dyes. The photophysical and electrochemical properties of the dyes were investigated. These two dyes show the whole visible light absorption when they are adsorbed on the TiO 2 film, which means that they are promising sensitizers for dye-sensitized solar cells. The absorption intensity of the triazolopyridine containing dye is higher than that of the benzotriazole containing dye, resulting in a better light harvesting. Thus…
Corruption in international business: A review and research agenda
2020
Abstract We systematically reviewed the literature on corruption in international business (137 articles) for the last 17 years between 1992 and 2019. Additionally, we identified seven research streams in this growing literature: (1) the legislation against corruption, (2) the determinants of corruption, (3) combating corruption, 4) the effect of corruption on firms, (5) the political environment and corruption, (6) corruption as a challenge to existing theories of management, and (7) the effect of corruption on foreign direct investment and trade. Based on this review, we recommend that strong international laws are needed to minimize the negative impact of corruption on international busi…