Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pablo Sanchis solves the detection of the “island effect”

11.11.2002


The “island effect” is one of the main problems in photovoltaic compound solar systems.



The doctoral thesis of Pablo Sanchis, presented in the Public University of Navarre (Basque Country), proposes three main contributions: the first one is a new control strategy of a booster inverter for autonomous systems; the second one is a new implementation of impedance measurement method, and the third one, a new methodology for the design of drift method in frequency, which guarantees with total reliability the detection of operation in the island.

Growing interest in photovoltaic energy


This research arises from the information in power electronics of Pablo Sanchis and his interest for renewable energies. In this field, it was noticed that there was still a lot to research in the conversion phase of two types of existing photovoltaic systems, autonomous ones and compound ones.

During the phase of conversion energy coming from photovoltaic panels is transformed. At the output of this panel direct voltage of low level is produced. This voltage must be transformed through electronic power converters so that it can be used, usually in an alternate current voltage of 220 V and 50 Hz.

The thesis proposes solutions for both photovoltaic systems, autonomous and compounds. For the autonomous systems, the use of booster inverter is proposed as an alternative to conventional power converters. Actually, the innovation does not lie so much in the structure self as in the control strategy of the converter proposed in the thesis. The advantages of this converter are its validity to work with variable references, its high level to reject external disturbances and its high reliability. That is, it rejects efficiently disturbances and allows exceeding the provisional short circuits. Furthermore, the dynamic of operation is faster and more precise.

This converter has drawn the attention of Laboratoire d’Electrotechnique et Electronique Industrielle de Toulouse (France). In fact, they have signed a partnership agreement with this University to use it in hydrogen fuel cell systems.

Compound photovoltaic systems

In the second part, the thesis studies the compound photovoltaic systems and, in particular, two problems that appear within those structures: the island effect and the filtering in single-phase inverters.

As for the first one, the “island effect”, it constitutes one of the main reasons for reluctance of power supply companies to accept the connection to its mains of distributed generation systems. For example, in case of a house with photovoltaic panels on the ceiling connected to the electric power supply. In a given moment, due to maintenance reasons or for any other reason, the electric power supply is turned off. However, the photovoltaic system can still keep the voltage in the mains sector that has been switched off. That is known as the island effect and is very dangerous, because the staff that are doing maintenance tasks believe there is no voltage, when indeed there is, as the photovoltaic system continuous generating it. Obviously, that can cause serious accidents or even failures in the electrical system. Therefore, it is important to have a method that detects when occurs the island effect in order to switched off the photovoltaic system.

Due to the importance of the problem, the company INGETEAM of Pamplona, which designs and produces converters for photovoltaic systems, addressed to the team of researches of the Public University of Navarre in order to obtain an efficient algorithm to detect the operation in island then to be introduced in photovoltaic converters that they commercialise.

Once the different methods proposed in the scientific literature were studied, Pablo Sanchis focused on two of them, the impedance measurement method and the drift method in frequency. The research team ignored the capacity of the first one, required by the German regulation. As for the drift in frequency, they sensed it was one of the best methods.

Once the impedance measurement method was analysed, Pablo Sanchis developed a new valid technique to go beyond the German regulation. This new method allows ensuring the island detection in any real operation condition, which makes it an optimal method.

Garazi Andonegi | alfa
Further information:
http://www.basqueresearch.com/index.asp?Gelaxka=1&hizk=I
http://www.unavarra.es

More articles from Power and Electrical Engineering:

nachricht Fraunhofer Researchers Develop High-Pressure Sensors for Extreme Temperature
28.06.2017 | Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration IZM

nachricht Touch Displays WAY-AX and WAY-DX by WayCon
27.06.2017 | WayCon Positionsmesstechnik GmbH

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Extensive Funding for Research on Chromatin, Adrenal Gland, and Cancer Therapy

28.06.2017 | Awards Funding

Predicting eruptions using satellites and math

28.06.2017 | Earth Sciences

Extremely fine measurements of motion in orbiting supermassive black holes

28.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>