Search results for "Volt"
showing 10 items of 2187 documents
Achieving maximum power transfer in a multi-source renewable system
2014
In this paper, a multi-source DC-DC power system is proposed for renewable applications. A multi-input, single inductor power converter controlled by two interacting control loops is designed. The steady-state and small-signal analysis of the designed system is carried out. A battery-photovoltaic system is designed as an application example. Both the output voltage and maximum power point of solar panels are properly controlled to achieve high performances of the whole system. Experimental results on a 48 V laboratory prototype are presented to discuss system performances.
Measurement Issues for the Characterization of Medium Voltage Grids Communications
2013
This paper is focused on the measurement issues and procedures for the characterization of medium voltage grids for narrowband power line communications (NB-PLCs), in the perspective of the use and integration of such technology into smart grids communication networks. The fundamentals are given for the characterization of the PLC channel, by means of noise and attenuation measurements. Suitable procedures are also developed for the characterization and modeling of the power system components in the frequency range of interest. Furthermore, the complete model of the PLC system is experimentally validated in a real case study.
Performance of the Glass Block in Photovoltaic Generation
2015
In this article is presented the preliminary evaluation of the performance of radiation transmission of glass block, used in support of photovoltaic cells, investigating different internal surface points of the block, which are subject to different shading during daylight hours. The aim is to establish how the edging setting, the only opaque element, can reduce the amount of light radiation during the day, introducing in this way a reduction of efficiency of the entire generation system. The generation system can be based on traditional photovoltaic cells or on the most suitable dye sensitized solar cells. An experimental measurement setup employing a microprocessor-based instrument has bee…
CIGS PV Module Characteristic Curves Under Chemical Composition and Thickness Variations
2014
This paper analyzes how the electrical characteristics of a CIGS photovoltaic module are affected by the chemical composition and by the thickness variations of the CIGS absorber. The electrical characteristics here considered are the short circuit current, the open circuit voltage, the efficiency and the power peak. The chemical composition is varied by tuning the ratio between gallium and indium. This analysis has been performed by means of the wxAMPS software, developed by the University of Illinois. The above variations have been taken into account on a PV module made of 72 cells. This analysis has been carried out employing a PV module mathematical model developed and implemented by th…
Nonlinear droop control for minimum power losses operation in islanded microgrids
2017
In this work, a modified primary regulation technique is proposed to control one of the inverter interfaced units feeding an islanded microgrid. The proposed approach employs an off-line minimum losses Optimal Power Flow, OPF, to extract a lookup table for the composition of the droop curve. Simulations prove that generators reach an operating point that corresponds to a minimum loss operation for the relevant power flow distribution. Since OPF has been implemented with frequency and voltage dependent models, the results of the modified droop are stable and also energy efficient. Further studies will address further analysis on systems showing different R/X ratio and modeling of more genera…
Design and control of a novel multi-source renewable energy system
2014
In this paper, a novel multi-input, single-inductor architecture is proposed. An innovative hysteretic control strategy of both the output voltage and the sources operating point control is designed and tested. Benefits brought by the proposed architecture over existing solutions are widely investigated. As an example, the design of a 48 V dual input system which is fed by photovoltaic and thermo-electric generators is proposed. Design guidelines are given and simulation results are presented to test the efficiency of the proposed architecture.
A novel implicit correlation for the operative temperature of a PV panel
2012
Abstract The operating temperature of a commercial PV panel strongly affects the electric power output of the devices. The prediction of the operating temperature therefore plays a central role in the economic and energy assessment of PV systems. The authors propose a new implicit correlation that takes into account the standard weather variables but also the regimen of PV panel in terms of the proximity to the maximum power points. Data coming from an experimental setup were processed by using the least squares technique. To validate the reliability of the correlation, a comparison between expected values and data from other common correlations were done. The results show that the regimen …
Adaptation of two-state (binary) optical fibre loop sensors for industrial use
2005
The paper presents an attempt to unify the construction of two state optical fibre loop sensor and possibility of adapting it to the various traditional constructions and casings of industrial sensors. This enables module structure of sensors based on construction of industrial application (master) and mensurative optical fibre loop (slave). Mensurative properties are determined by traditional (mainly mechanical) measuring system ex. temperature, displacement, and optical properties are determined by characteristics of auxiliary optical system (standardised and unified). Such attitude to a subject is illustrated in this paper by the examples of threshold displacement sensor, temperature, vo…
Connection Of System Measuring Voltages And Currents Of High Voltage Power Line To A Microcomputer By Optical Fibre Link
1986
The prototype of equipment for service of the measuring units of power high voltage line is presented. That system is composed of the transmitter /with A/D conversion/, optical fibre data link and receiver feeding the output into the microcomputer. The application of this equipment in the automatic protection system protecting the power network against short-circuit is described.
An Optimal Monitoring Program for Obtaining Voltage Sag System Indexes
2006
This paper presents a meter placement method for voltage sags monitoring in large transmission systems. An integer programming-based modeling is proposed for choosing the locations of power quality meters. A branch-and-bound-type algorithm is used to solve the optimization problem. A large transmission network is used to validate the method. Stochastic assessment of voltage sags is applied to the test network to obtain simulated monitoring results. Voltage sags system indexes are calculated from monitoring programs designed according to the optimization method. Comparisons with the system indexes obtained from a full monitoring program show the applicability of the method.