This paper presents the results of experimental work on flywheel energy storage systems for city buses. An efficient electronic hardware scheme is used to start the flywheel and traction machines. This scheme has been designed, fabricated and tested in our laboratory. A low frequency a.c. has been derived from an inverter fed from a three-phase uncontrolled rectifier to start the commutatorless d.c. motors. Commutation is achieved by using a capacitor and two auxiliary thyristors, whose ratings could be a fraction of full machine ratings, as they are needed during starting only. The frequency of the inverter output is controlled by a function generator. For successful commutation in all modes of operation. a capacitor voltage sensor circuit has been employed.


Evaluation of hybridsolar-wind-hydrogenenergy system based on methanol electrolyzer
Budak, Yagmur; DEVRİM, YILSER (Wiley, 2020-10-01)
In this study, it is aimed to meet the annual electricity and heating needs of a house without interruption with the photovoltaic panel, wind turbine, methanol electrolyzer, and high temperature proton exchange membrane fuel cell system. The system results show that the use of the 2 WT with 18 PV was enough to provide the need of the methanol electrolyzer, which provides requirements of the high temperature proton exchange membrane fuel cell. The produced heat by the fuel cell was used to meet the heat requ...
Kinetics of hydrogen generation from hydrolysis of sodium borohydride on Pt/C catalyst in a flow reactor
Boran, Asli; Erkan, Serdar; Özkar, Saim; Eroglu, Inci (Wiley, 2013-04-01)
Here, we report the results of a kinetic study on the hydrogen generation from the catalytic hydrolysis of sodium borohydride in a differential flow reactor. As catalyst platinum supported on carbon (Pt/C) was used in two forms: either as powder or coated on carbon cloth. For optimization of the system several parameters such as sodium hydroxide concentration, sodium borohydride concentration and the flow rate of the feed solution were varied. It was found that the H2 generation rate increases with an incre...
Concentrated Solar Power Harvesting Using Self-powered, Wireless, Thin-profile, Lightweight Solar Tiles
Ardanuc, Serhan M.; Lal, Amit; Jones, Samuel C. (ASME International, 2011-08-01)
This paper presents a modular and scalable approach to concentrated solar power (CSP) harvesting by using low-profile, light-weight, sun-tracking, millimeter-to-centimeter-scale mirror arrays that can be wirelessly controlled to reflect the incident solar energy to a central receiver. Conventional, utility-scale CSP plants use large-area heliostats, parabolic troughs, or dish collectors that are not only heavy and bulky, but also require significant labor for installation and maintenance infrastructure. Fur...
PEM fuel cell degradation effects on the performance of a stand-alone solar energy system
ÖZDEN, Ender; Tarı, İlker (Elsevier BV, 2017-05-04)
After comparing fresh and degraded performances of Polymer Electrolyte Membrane (PEM) based components of a hydrogen cycle with the help of computational fluid dynamics simulations, recently established stand-alone solar energy system producing hydrogen for energy storage is investigated focusing on the effects of degradation of fuel cells on the overall performance of the system. A complete model of the system has been developed using TRNSYS, and a degraded PEM Fuel Cell Subsystem has been incorporated int...
Electrochemical performance and modeling of lithium-sulfur batteries with varying carbon to sulfur ratios
Michaelis, Charles; Erisen, Nisa; PALA, DAMLA EROĞLU; Koenig, Gary M. (Wiley, 2019-02-01)
Lithium-sulfur batteries have attracted much research interest because of their high theoretical energy density and low-cost raw materials. While the electrodes are composed of readily available materials, the processes that occur within the cell are complex, and the electrochemical performance of these batteries is very sensitive to a number of cell processing parameters. Herein, a simple electrochemical model will be used to predict, with quantitative agreement, the electrochemical properties of lithium-s...
Citation Formats
S. TRIPATHY, “ELECTRIC DRIVE FOR FLYWHEEL ENERGY-STORAGE,” ENERGY CONVERSION AND MANAGEMENT, pp. 127–138, 1994, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/64269.