Search results for "Grid-connected photovoltaic power system"
showing 10 items of 38 documents
Reconfiguration Techniques of Partial Shaded PV Systems for the Maximization of Electrical Energy Production
2007
In this paper, the research of the optimal layout of photovoltaic (PV) modules in a PV array giving the maximum output power under different shaded working conditions is carried out. The particular condition of non uniform solar exposition of the modules is analyzed. The study of the different configurations has been carried out starting from a circuital model used for the design of PV cells and for the simulation of the working behavior of PV arrays. The attained results appear to be interesting although the complexity of the problem in mathematical terms is huge when the number of panels is high. Moreover, the results confirm that this approach often allows to attain a higher electrical e…
Higher PV Module Efficiency by a Novel CBS Bypass
2011
There is an increasing focus on reducing costs and improving efficiency for photovoltaic (PV) cells and modules as well as finding a more efficient approach to the product manufacturing. This letter introduces an innovative solution to bypass shaded PV cells instead of a traditional Schottky diode, in order to avoid overheating of cells in the case of partial shading. The goal is to reduce the power dissipation and improve the general efficiency of a PV generator. A novel device called cool bypass switch is then presented. It is made up of a Power MOS driven by a controller with the task to charge a storage capacitor. Tests and comparisons with standard Schottky diodes are then performed an…
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…
Survey on power increase of power by employment of PV reconfigurator
2015
This paper shows the performance of a PV system under shadow projection on PV panels. The reconfiguration techniques, employing a microprocessor-based system, modifies the layout of the PV plant by physically changing the connections among modules, in order to recover the loss of power due to the shadows. Different cases have been considered to evaluate the increase of power.
Distribution grid analysys through PSAT open source tools
2015
In this paper a study of an electrical distribution grid with presence of renewable energy sources performed using the Power System Analysis Tool is presented. The paper describes the load flow analysis of a real existing grid owned by the Italian DSO “ENEL Distribuzione SpA” and located in an urban area.
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.
Load mismatch of grid-connected photovoltaic systems: Review of the effects and analysis in an urban context
2013
Abstract The mismatch between generated and consumed electricity is a relevant topic of the energy and economic assessment of photovoltaic (PV) systems. Due to the load mismatch some amount of PV electricity may be exported to the grid because the electrical demand is temporarily lower than production, whereas a consumption, which is higher than production and/or that does not match the available PV generation, will require to be supplemented by the public grid electricity. The presence of the load mismatch can cause the effect of disadvantageously purchasing electricity from the grid and/or squandering the unexploited PV energy. If only a very small part of the PV generation is used to sup…
Power management of grid-connected photovoltaic inverter with storage battery
2011
With increased penetration of PV generation in the power grid, it becomes necessary to control the PV generation similar to the conventional power sources. Grid-connected PV systems equipped with storage batteries are capable of active power control. PV power generation can be either fed into the grid or stored in the battery. This paper presents a deterministic power management algorithm that uses closed-form approximations derived from analytical loss models. It can be configured to maximize the efficiency or the revenue in a liberalized electricity market. The battery controller emulates an optimum load-line in which the PV power is autonomously shared between the battery and the feed-in…
Hydrogen back-up power system with photovoltaic direct energy transfer regulation and interleaved boost for space applicattions
2012
This work details a power conditioning unit for photovoltaic/hydrogen based energy systems in space applications. The power conversion techniques applied are similar to the ones used on photovoltaic/battery space power systems. A direct energy transfer photovoltaic regulator is devised for feeding two outputs; the first output corresponds to the main unregulated battery bus and the second output sets a power path to feed an electrolyser. A modular fuel cell converter completes the system and operates when photovoltaic energy is not available or load demand exceeds the generated photovoltaic power, providing electrical power from a fuel cell. An ancillary battery, located in the main bus, di…
PV System Design for Off-Grid Applications
2015
Solar photovoltaic (PV) technology has the versatility and flexibility for developing off-grid electricity system for different regions, especially in remote rural areas. While conventionally straight forward designs were used to set up off-grid PV-based system in many areas for wide range of applications, it is now possible to adapt a smart design approach for the off-grid solar PV hybrid system. A range of off-grid system configurations are possible, depending upon load requirements and their electrical properties as well as on site-specific available energy resources. The overall goal of the off-gird system design should be such that it should provide maximum efficiency, reliability and …