Search results for "duty cycle"
showing 10 items of 46 documents
Silica masks for improved surface poling of lithium niobate
2005
Surface periodic poling of congruent lithium niobate was performed with the aid of photolithographically defined silica masks. The latter helped improving the control of duty cycle in the periodic domain poling, with 50:50 mark-to-space ratios. The role of silica was ascertained by numerically solving the Poisson equation.
Maximum Power Point Tracker for Standalone PV System Using Neural Networks
2019
In this work, designing and implementation of a maximum power point tracker (MPPT) based on an artificial neural network is proposed. The output voltage of the selected photovoltaic array is controlled by a DC to DC boost converter in a way that the PV array generates the available possible maximum power correspond to the available solar irradiance and temperature. The neural network (NN) is capable of forecasting the required terminal voltage of the PV array in order to generate the possible maximum power. The pulse width modulation (PWM) signal, which drives the boost converter, is generated through a raspberry pi according to the forecasted terminal voltage. The terminal voltage of the P…
The MAMI-project
2008
In the energy region up to one GeV the "racetrack"-microtron /1/ offers an economic way to achieve a 100% duty factor e--beam with a high current (IO0~A) and a well defined energy (Ap/p ~ 10-4). Such an e--beam appears to be ideal for the experimental investigation of the nucleus: coincidence experiments of the type (e,e'x) and (e,e'xy) become possible in a wide kinematical region yielding information about the response of the nucleus to the transferred energy and momentum. By the method of bremsstrahl-tagging, for the f i r s t time, rather intensive ( few times 107/sec) photon beams with high monochromaticity and well known fluxes wi l l be available. To make the best use out of such new …
First results from MAMI
1993
Abstract The 100% duty factor electron accelerator MAMI (Mainzer Mikrotron) has gone into operation. First experiments with quasi-monochromatic real photons have been performed. First results, mostly preliminary, are presented.
Identification of a Hammerstein model for DC/DC converters operating in CCM
2005
This paper deals with a method for identification of a Hammerstein model of DC-DC converters operating in continuous conduction mode (CCM). This model has the duty cycle and the output voltage as input and output, respectively; it consists of a static nonlinearity and a linear and time-invariant model. The aim of the modeling the system by means of a Hammerstein model is due to its capability of describing the converter in a range of steady-state operating points instead of a desired well defined operating point as occurs for the small-signal models which are the more common mathematical description to approach the study of the converters themselves. The nonlinear characteristic of the Hamm…
Nonlinear Modeling of DC/DC Converters Using the Hammerstein's Approach
2007
This paper deals with the modelling of highly nonlinear switching power-electronics converters using black-box identification methods. The duty cycle and the output voltage are chosen, respectively, as the input and the output of the model. A nonlinear Hammerstein-type mathematical model, consisting of a static nonlinearity and a linear time-invariant model, is considered in order to cope with the well-known limitations of the more common small-signal models, i.e. the entity of the variations of the variables around a well-defined steady-state operating point and the incorrect reproduction of the steady-state behavior corresponding to input step variations from the above steady-state operat…
Application of circuit theory for extraction of water from oil
2011
This paper discusses optimization of the performance of a pulsed dc electrostatic coalescer, a device that is used in the oil industry to increase the speed of separation of water from a water-in-oil emulsion. A previously found criterion for optimum performance, the charge hypothesis, is reviewed. Analysis by circuit theory shows that the performance may be improved through selecting an optimum switching frequency and duty ratio, improving the design of the pulse train generator, and making physical modifications to the coalescer apparatus. The addition of an external charging circuit is beneficial. Experiments on the modified system could contribute to a better understanding of the physic…
Determination of a pre-heating sequence for the DONES Target Assembly
2021
Abstract Within the activities promoted by the EUROfusion consortium in support of the design and construction of the DEMO Oriented NEutron Source (DONES), a mock-up of its Target Assembly (TA), based on the configuration with a “bayonet” Back-Plate (BP) and available at ENEA Brasimone labs, is being adopted for the execution of experimental activities aiming at the validation of specific aspects of the target design. Despite the “integral”-TA concept is the current reference, experimental tests concerning the TA pre-heating phase are not significantly affected by the TA concept and are still representative even though conducted on the bayonet-TA concept. Indeed, the main objective of the p…
ARGO-YBJ constraints on very high energy emission from GRBs
2009
The ARGO-YBJ (Astrophysical Radiation Ground-based Observatory at YangBaJing) experiment is designed for very high energy $\gamma$-astronomy and cosmic ray researches. Due to the full coverage of a large area ($5600 m^2$) with resistive plate chambers at a very high altitude (4300 m a.s.l.), the ARGO-YBJ detector is used to search for transient phenomena, such as Gamma-ray bursts (GRBs). Because the ARGO-YBJ detector has a large field of view ($\sim$2 sr) and is operated with a high duty cycle ($>$90%), it is well suited for GRB surveying and can be operated in searches for high energy GRBs following alarms set by satellite-borne observations at lower energies. In this paper, the sensitivit…
A superconducting CW-LINAC for heavy ion acceleration at GSI
2017
The European physical journal / Web of Conferences 138, 01026 (2017). doi:10.1051/epjconf/201713801026