Search results for "Grid-connected"
showing 10 items of 48 documents
Effects of the Italian financial crisis on the photovoltaic dissemination in a southern city
2013
Abstract The aim of this paper is to estimate how the profitability of grid-connected PV (photovoltaic) systems may vary month by month due to the changes in all parameters involved in the economic evaluation (discount rate, PV electricity selling price, inflation rate, price of PV devices etc.). The effects of these variations were investigated for a district of a city in the South Italy (Palermo). The results of the analysis provided the trend of the actual coverage of the district power demand from June 2010 to August 2012. In particular the load match index, which considers the daily energy demand covered by PV systems, ranged from almost 30% to less than 12%, which is less than the val…
Numerical Analysis of Medium Scale PV Plants and Their Power-Flow Control System With a Simple Three Phase Inverter
2012
This paper presents a mathematical analysis of a medium scale Photovoltaic (PV) power generation system connected to the distribution network and of its control system, in which the conversion stage is unique thanks to the absence of a boost chopper. Boost choppers are usually used as actuator for maximum power point tracking (MPPT). The conducted analysis leads to the conclusion that the used inverter presents two degrees of freedom that can be easily exploited in a control system in which the inverter simultaneously realizes the interconnection to the grid and at the same time realizes the MPPT control. The structure of the control system is then presented, discussed and then validated by…
Performance of grid-connected PV system in Southern Norway
2015
This paper presents performance results from one of the first grid-connected photovoltaic (PV) systems in Norway. The 45 kWp system is mounted on top of a flat roof at the headquarters of a local utility company, Agder Energi, in the coastal town of Kristiansand. The system consists mainly of multi-crystalline silicon modules, with one thin film array. The system has been in operation since May 2011 and is instrumented for research and monitoring purposes. Data recorded include global and diffuse horizontal irradiation, tilted irradiation and other weather parameters, PV module temperatures, DC and AC current and voltage for three arrays, in addition to inverter power data and voltage quali…
Techno-economic optimum sizing of hybrid renewable energy system
2013
Using off grid hybrid renewable energy systems for rural electrification has become an attractive solution for those areas, where grid electricity is not feasible or cost of the grid extension is relatively large. Hybrid system combines several energy systems together, therefore it can supply high reliable electricity rather than a PV/battery system or a wind/battery system. But the most important thing is that the system should be economically attractive. To achieve both of these features, each of the components in the hybrid system should be optimally sized. This requires a detailed techno-economic analysis of different possible hybrid system configurations. The objective of this study is…
A simple and accurate model of photovoltaic modules for power system design
2014
Charging management of grid integrated battery for overcoming the intermittency of RE sources
2016
Grid integration of distributed generation (DG) systems with energy storage system can help not only in increasing the more penetration of DG systems into the network but it is also going to help in improving the power system dynamics, stability and control as well as helping in demand side management. In this work, a method for integrating an energy storage with the grid which can provide the prescribed active and reactive power to the grid is presented. The main objective is to ensure a high state of charge (SOC) of the battery with the innovative control system for taking part in power system control. Active and reactive power dispatching using a bi-directional DC-DC converters and a vol…
Photovoltaic based active generator: Energy control system using stateflow analysis
2015
At present, most of the grid connected photovoltaic (PV) systems are operating at maximum power points and injecting power in uncontrolled way. Thus, active generator will be a good solution to support instantaneous power balance, frequency control and maintaining the power quality with controllable power injection. This new mode of active generator needs innovative power management. The new proposed energy control system for active generator might help to manage the energy within the micro-grid environment. In this work, the focus is to manage the energy among the PV based active generator, load and interconnected grid and energy controller architecture for that purpose is presented. It co…
Manufacturing tolerances effects on PV array energy production
2014
This paper investigates the tolerance effects of commercial photovoltaic modules in terms of electrical energy reduction of photovoltaic plants. Several commercial modules, having the same rated power, present different power tolerance values. A wide tolerance is an indicator of possible defects or differences in the production process and is responsible of remarkable reductions in the electricity production of photovoltaic plants. In this paper, thanks to the development of a suitable simulation tool, several simulations have been carried out, considering different tolerance and shading conditions for the PV array. Simulation results quantify the peak power value of the different plant con…
A Novel Symmetrical Boost Modulation Method for qZS-based CHB Inverters
2020
Quasi-Z-source cascaded H-bridge (qZS-CHB) inverters are arising as an innovation in the field of the electrical conversion for PV applications. This type of converters inherit the advantages of multilevel inverters and single-stage configuration. In this context, this paper proposes a novel symmetrical boost modulation strategy for qZS CHB multilevel inverters to increase the performance in terms of voltage stresses and power quality. The novelty lies in the adoption of a different concept to generate the shoot-through states compared to the traditional methods. Simulation analysis in a grid connected application to evaluate the benefits of this boost method is performed in the MATLAB/PLEC…
A New Device for the Control and the Connection to the Grid of Combined RES-based Generators and Electric Storage Systems
2013
In this paper a new device for the control and the connection to the supply utility grid of combined RES-based generators and electric storage systems is presented. The device is a bidirectional converter that can be controlled so as to facilitate the interface between the low voltage grid and photovoltaic or wind generators combined with batteries, contemporary addressing the requirements of the reference technical standards for users connection and providing different ancillary services. In the paper the functioning of the device and its circuit diagram are described, the single parts are shown and the potentiality of its control system are commented. © 2013 IEEE.