Planung und Betriebsoptimierung von Verteilungsnetzen im liberalisierten Markt unter Nutzung neuer Technologien

Ohne Zusammenfassung Kurzfassung eines Vortrags, gehalten anl?sslich der gemeinsamen Fachtagung der Energietechnischen Gesellschaften des ?VE, SEV und VDE „Netze im 3. Jahrtausend — Technik und Wirtschaft” (gleichzeitig 38. Fachtagung der ?sterreichischen Gesellschaft für Energietechnik im ?VE), die vom 15. bis 17. November 2000 in Innsbruck stattfindet.     

串联补偿技术在远距离高电压交流输电系统中的应用

文章针对远距离,重载,跨区间交流输电系统的稳定及传输容量问题,提出了串联补偿方案,并围绕采用串联补偿技术所应考虑的一些主要问题,以远距输电系统为例进行了讨论,文中还从理论的角度阐述了可控串补提高系统稳定性,增加系统功率传输容量的原理,通过仿真对其有效性进行了论证并与固定串补进行了对比。     

Annotated news corpora and a lexicon for sentiment analysis in Slovene

In this study, we introduce Slovene web-crawled news corpora with sentiment annotation on three levels of granularity: sentence, paragraph and document levels. We describe the methodology and tools that were required for their construction. The corpora contain more than 250,000 documents with political, business, economic and financial content from five Slovene media resources on the web. More than 10,000 of them were manually annotated as negative, neutral or positive. All corpora are publicly available under a Creative Commons copyright license. We used the annotated documents to construct a Slovene sentiment lexicon, which is the first of its kind for Slovene, and to assess the sentiment classification approaches used. The constructed corpora were also utilised to monitor within-the-document sentiment dynamics, its changes over time and relations with news topics. We show that sentiment is, on average, more explicit at the beginning of documents, and it loses sharpness towards the end of documents.     

Analysis of Slovenian research community through bibliographic networks

Science is a societal process, designed on widely accepted general rules which facilitate its development. Productive researchers are viewed from the perspective of a social network of their interpersonal relations. In this paper we address performance of Slovenian research community using bibliographic networks between the years 1970 and 2015 from various aspects which determine prolific science. We focus on basic determinants of research performance including productivity, collaboration, internationality, and interdisciplinarity. For each of the determinants, we select a set of statistics and network measures to investigate the state of each in every year of the analyzed period. The analysis is based on high quality data from manually curated information systems. We interpret the results by relating them to important historical events impacting Slovenia and to domestic expenditure for research and development. Our results clearly demonstrate causal relations between the performance of research community and changes in wider society. Political and financial stability together with concise measuring of scientific productivity established soon after Slovenia won independence from Yugoslavia in 1991 had positive influence on all determinants. They were further leveraged by foundation of Slovenian research agency and joining EU and NATO. Publish and perish phenomenon, negative impacts of financial crisis in 2008–2014 and reshaping the domestic expenditure for research and development after 2008 have also clear response in scientific community. In the paper, we also study the researcher’s career productivity cycles and present the analysis of the career productivity for all registered researchers in Slovenia.     

NETOMAC在静止调相器仿真中的应用

应用德国西门子公司的电力系统仿真软件ＮＥＴＯＭＡＣ,在瞬时值模式和稳态值模式下,利用不同的模型,对ＦＡＣＴＳ技术的核心装置之一－静止调相器进行了仿真研究。结果表明,该软件所具有的某些特点,为装置主电路参数的选择、保护系统的设计、控制策略的确定以及装置与电力系统之间的相互作用等几个方面的仿真研究提供了的方便,非常适合对电力电子装置的开发及其在系统中运行方式的研究进行仿真。     

A Boundary Point Method to Solve Semidefinite Programs

We investigate the augmented Lagrangian penalty function approach to solve semidefinite programs. It turns out that this method generates iterates which lie on the boundary of the cone of semidefinite matrices which are driven to the affine subspace described by the linear equations defining the semidefinite program. We provide some computational experience with this method and show in particular, that it allows to compute the theta number of a graph to reasonably high accuracy for instances which are beyond reach by other methods. Supported in part by EU project Algorithmic Discrete Optimization (ADONET), MRTN-CT-2003-504438.     

Circuit breaker model for digital simulation based on Mayr's andCassie's differential arc equations

A model of a circuit breaker for digital simulation programs based on the Mayr's and Cassie's differential arc equations was developed. The model can be used to determine the current interruption capability of the circuit breaker. The theoretical basis and the structure of the model are described. The model is verified on a sample of measured results, and the use of the model for practical application is demonstrated. Although the validation of the model is limited to the vicinity of current zero, it can be usefully used. Its advantage lies in the fact that the simulation programs set and solve the system of breaker and network differential equations. Calculation of a breaker capability can so be done using a complex network     

Szenarien zur Entwicklung der Stromversorgungsnetze

Globalization and deregulation have a strong impact on developments in the electrical industry. In emerging countries, energy demand is increasing rapidly. In the industrialized countries, the increase in demand is low, however based on a high existing level. This situation has a strong influence on developments in power systems. The most important characteristics in power system development is discussed for industrialized countries. Electrical manufacturers develop and deliver equipment and systems which can solve system problems in an economic manner.     

Modeling Long-Term Electricity Forward Prices

In contrast to forwards and futures on storable commodities, prices of long-term electricity forwards exhibit a dynamics different to that of short-term and midterm prices. We model long-term electricity forward prices through demand and supply of electricity, adjusted with a risk premium. Long-term prices of electricity, oil, coal, natural gas, emission allowance, imported electricity, and aluminum are modeled with a vector autoregressive model (VAR). For estimation, we use weekly prices of far-maturity forwards relevant for the Nordic electricity market. Although electricity prices experienced a few substantial shocks during the period we analyzed, there is no evidence of a structural break. Cointegration analysis reveals two stationary long-run relationships between all variables except the gas price, indicating that these variables move together over time. We find some influence of the risk premium, however not on the long-term electricity forwards at Nord Pool.