Search results for "Dc voltage"
showing 4 items of 4 documents
A New Approach to Partial Discharge Detection Under DC Voltage: Application to Different Materials
2021
Usability of a new Direct Current Periodic waveform for partial discharge qualification in HVDC systems is exemplified by tests performed on different materials.
Thermally Tunable Surface Acoustic Wave Cavities
2020
We experimentally demonstrate the dynamical tuning of the acoustic field in a surface acoustic wave (SAW) cavity defined by a periodic arrangement of metal stripes on LiNbO3 substrate. Applying a dc voltage to the ends of the metal grid results in a temperature rise due to resistive heating that changes the frequency response of the device up to 0.3%, which can be used to control the acoustic transmission through the structure. The timescale of the switching is demonstrated to be of about 200 ms. In addition, we have also performed finite-element simulations of the transmission spectrum of a model system, which exhibits a temperature dependence consistent with the experimental data. The adv…
Studying exotic nuclides close to the N = Z line at the HIGISOL facility
2003
The ion guide [1, 2] for heavy-ion fusion-evaporation reactions (HIGISOL) which was developed by Beraud et al. [3] has been implemented at the IGISOL facility in Jyvaskyla [4]. This system was modified over the past 5 years. Figure 1 shows the present set-up. The HIGISOL takes advantage of the different angular distributions of primary beam and reaction products: the primary beam is stopped in front of the stopping chamber and the reaction products enter the stopping chamber through a thin foil passing the beam stop. This so called “shadow” method removes the plasma effect since the primary beam is not ionising the stopping gas. In order to improve ion optical properties, mainly to reduce t…
Design of a Battery/Ultracapacitor Energy Storage System for Electric Vehicle Applications
2018
The battery/ultracapacitors (UCs) integration is able to provide notable advantages in the power management of an electric vehicle (EV), in terms of capability of both high energy storage and readiness to deal with fast load variations. In order to manage the charge (or discharge) of the UCs from (or towards) a DC voltage bus, a proper bi-directional converter is required. In this paper, a bi-directional DC-DC converter in connection with a stack of UCs is described and some power simulation results are provided. The proposed converter is a B2R (buck-boost regulator) type. The load is represented by a 40kW peak power, kept for a time window of 3s, as required by the Worldwide harmonized Lig…