Michael Weinhold

Improvement of power quality with advanced power electronic equipment

The quality of electrical energy supply, especially voltage quality is becoming more and more important in both industrialized and developing countries. An insufficient supply quality can lead to an inadequate quality of products, interruption of important industrial processes and therefore to economic losses. The amount of equipment and industrial processes which are sensitive to insufficient voltage quality, such as harmonics and sags, is increasing. This paper describes the main power quality problems and their solution with IGBT PWM converter-based power conditioning equipment.

The Energy Turnaround

When the tsunami hit the Fukushima atomic plant in Japan in March 2011, causing the reactor disaster, it was impossible to predict the consequences for the future of energy supply. Many countries have considerably strengthened their activities since then to realize an energy turnaround, i.e., a switch from nuclear power and fossil fuels to a more sustainable energy supply with increased use of regenerative energy resources such as wind or sun. Whereas only 55 states had political ambitions to expand the use of renewable energies in 2005, this number has increased to about 190 states in 2012. Also a change in attitudes can be observed. Early in 2012, more than 70 % of the French supported a phase-out of nuclear power – even though France was worldwide frontrunner in this area with a 75 % nuclear powered energy supply in the end of 2010. Germany takes an uncompromising approach in that it has officially decided to phase out nuclear power completely by 2022, although the economically strong parts in the country’s south receive more than 50 % of their electricity from nuclear power plants. This development towards a nuclear phase-out, which can be observed in other countries to a lesser extent, can be considered – in the jargon of BISE – as a ‘revolution’ more than an ‘evolution’. A revolution always comes with risks, but also offers opportunities. In the following we will show that the energy turnaround opens up a wide range of opportunities – if it is addressed responsibly and with a well-conceived plan. First of all it should be mentioned that this ‘revolution’ may be a current topic, but in principle is not a new one. Business & Information Systems Engineering (BISE) addressed this issue in a very early stage. For example, in issue 4/2008, the high potential of IS beyond Green IT regarding an energy turnaround was pointed out. Exactly one year later, in BISE 4/2009, the responsibility of our discipline for our planet and the threat of a worldwide resource crisis were discussed. The editorial 1/2012 and the corresponding special focus issue focused on “Smart Grids” and their relevance for the energy turnaround. All in all, we can see that the international community was aware of the energy turnaround’s relevance even before the Fukushima reactor disaster. But this is not sufficient. Rather, to ensure the success of the energy turnaround it is essential that single countries do not indulge in blind activism. This is especially important because the aims associated with the energy turnaround, such as an increased use of regenerative energies, will lead to major challenges (e.g., it is Germany’s goal to increase the use of regenerative energies from 20 % in 2011 to at least 35 % in 2020). Some of these challenges are briefly mentioned in the following: • The yield of renewable energies is often difficult to plan and control – e.g., wind and solar energy can only be extracted during suitable weather conditions. This frequently leads to a mismatch between the times of supply and demand. • These supply risks require energy storage and conventional power plants. Construction projects for energy storage are often in conflict with current regulations concerning environmental protection or are unpopular with the public. Moreover, many concepts regarding the storage of energy are still in research and development phases and thus cannot yet be used commercially. Also, construction projects for conventional power plants are often highly unpopular within the local population. • Onshore wind parks also have a negative impact on nature and hence are more and more subject to critical valuation by the public. • The transport of renewable energy requires a massive expansion of the super grid at national as well as international levels. In Germany alone, about 400 kilometers of the current distribution system would have to be enhanced and further 850 kilometers would have to be newly built until 2015. This seems challenging considering that Germany constructed only 90 kilometers from 2006 until 2011. According to the “dena-Netzstudie II”, a further 3600 kilometers are supposedly needed by 2020. Also,

Blackout Prevention by Online Network and Protection Security Assessment

The proposed paper describes some of the most important parts of a modern security system Siguardreg (patent pending), which can be connected to control centers via standardized interfaces for the exchange of the actual state-estimator results of the power system.

Optionen einer nachhaltigen Energietechnik

Die zweite Halfte des 19. Jahrhunderts war eine Zeit der Pioniere: Werner von Siemens grundete mit Georg Halske im Jahr 1847 das Unternehmen „Siemens & Halske“, damals eine Firma mit 400 Mitarbeitern; heute arbeiten uber 400.000 Menschen bei Siemens. Werner von Siemens entdeckte 1866 das dynamo-elektrische Prinzip und damit den wirtschaftlichsten Weg, Strom zu erzeugen. Ende der 1870er-Jahre beschloss Thomas A. Edison, mit seiner Gluhlampe Licht in alle Haushalte zu bringen. George Westinghouse und Nikola Tesla experimentierten mit Wechselstrom, Oskar von Miller gelang es erstmals, grose Energiemengen uber 175 km zu transportieren — und Werner von Siemens erkannte, dass Strom „unzahlige Einrichtungen in Hausern, Fabriken und auf den Strasen hervorrufen wird, welche zur Erleichterung des Lebens dienen“. Viele davon entwickelte er gleich selbst: etwa die erste elektrische Eisenbahn, den elektrischen Kutschenwagen — einen Vorlaufer von Elektroauto und Strasenbahn — sowie den ersten elektrischen Aufzug … um 1890 begann dann endgultig die Elektrifizierung der Welt.