Iskanje po katalogu digitalne knjižnice

Opis: This Doctoral Thesis deals with the mechanisms for cross-border interchange and activation of the regulating reserves (RRs), i.e., Imbalance Netting Process (INP) and Cross-Border Activation of the RRs (CBRR), between participating Control Areas (CAs), to reduce the costs of balancing energy. The main objective of INP is to interchange the RRs between participating CAs with opposite signs of interchange power variation. In comparison, the main objective of CBRR is to activate the RRs in participating CAs with the same signs of interchange power variation. Both the INP and CBRR aim to release the RRs and reduce balancing energy as part of the power system's safe operation. The Thesis's main objective is to analyze the impact of the mechanisms for cross-border interchange and activation of the RRs on mutual oscillations of participating CAs and stability for small disturbances. The Thesis's secondary objective is to analyze the impact of the INP and CBRR on frequency quality, on the provision of Load-Frequency Control (LFC), on balancing energy and unintended exchange of energies between participating CAs. Frequency quality in Continental Europe (CE) has been declining in recent years, so it is important that the mechanisms for cross-border interchange and activation of the RRs do not further impair its quality. Both the classic INP and CBRR include a frequency-dependent contribution and, therefore, inherently affect the frequency response of the participating CAs, which is not discussed in the literature. Thus, the impact of the classic INP and CBRR on frequency quality and the provision of LFC is thoroughly evaluated with dynamic simulations of a three-CA test system and eigenvalue analysis of a two-CA system. It is demonstrated that both the classic INP and CBRR reduce the damping of the entire power system. Therefore, a modified implementation of the classic INP and CBRR is presented, and improved INP and CBRR are proposed, which have no impact on the mutual oscillations of participating CAs and stability for small disturbances. Furthermore, the dynamic simulations results confirm that the frequency quality can be improved by the classic INP and CBRR, although there are also cases where it can deteriorate. However, the improved INP and CBRR generally improve the frequency quality in all cases. The improved INP and CBRR also enhance the provision of LFC compared to the classic INP and CBRR. Moreover, the improved INP and CBRR reduce the unintended exchange of energies, thus increasing the economic effects of the INP's and CBRR's activation. The improved INP increases energy exchange, therefore positive economic benefits can be expected in comparison to the system with the classic INP. However, the improved CBRR reduces energy exchange, therefore positive economic benefits can be expected in comparison to the system with the classic CBRR, since energy exchange is paid by CA via bidding process.
Ključne besede: load-frequency control, imbalance netting, cross-border activation, balancing energy, regulating reserves, eigenvalue analysis, performance indicators, area control error, rate of change of frequency, control area
Objavljeno v DKUM: 09.03.2023; Ogledov: 594; Prenosov: 102
Celotno besedilo (14,64 MB)

Opis: The diploma thesis focuses on the influence of the French, Italian and Spanish language on the Standard Southern British English pronunciation. The research is based on the recordings of 10 French, 9 Italian and 9 Spanish students who spent half a year in England as Erasmus exchange students. The theoretical part starts with an introductory chapter describing a short history of all four languages, as well as the position of the English language in the world and in the European Union. East Midlands English and Standard Southern British English are then presented with their phonological characteristics. Furthermore, the vowel systems of French, Italian and Spanish language are presented together with the most common errors the speakers of these languages encounter when pronouncing English vowels. In the following chapter the term “interlanguage” and research methods as Contrastive Analysis and Error Analysis are described. In the last segment of the theoretical part we are dealing with so-called formants which are frequencies that the vowels are made of and are essential for identification of a vowel. In the empirical part, Error Analysis is used as a research method. The key part of the research is the analysis of the recordings of foreign students’ pronunciation of 11 SSBE vowels. The results of the research clearly prove a strong influence of the French, Italian, and Spanish accents on the pronunciation of SSBE vowels, as well as a great impact of General American. To analyse the data, the descriptive method was used. The findings of the dissertation could be of help to other researchers or English teachers should they find themselves teaching in France, Italy or Spain.
Ključne besede: Standard Southern British English, vowels, formants, foreign students, Error Analysis
Objavljeno v DKUM: 08.09.2016; Ogledov: 1601; Prenosov: 90
Celotno besedilo (1,98 MB)