Security Constrained Multi-Stage Transmission Expansion Planning Considering a Continuously Variable Series Reactor

This paper introduces a Continuously Variable Series Reactor (CVSR) to the transmission expansion planning (TEP) problem. The CVSR is a FACTS-like device which has the capability of controlling the overall impedance of the transmission line. However, the cost of the CVSR is about one tenth of a similar rated FACTS device which potentially allows large numbers of devices to be installed. The multi-stage TEP with the CVSR considering the $N-1$ security constraints is formulated as a mixed integer linear programming model. The nonlinear part of the power flow introduced by the variable reactance is linearized by a reformulation technique. To reduce the computational burden for a practical large scale system, a decomposition approach is proposed. The detailed simulation results on the IEEE 24-bus and a more practical Polish 2383-bus system demonstrate the effectiveness of the approach. Moreover, the appropriately allocated CVSRs add flexibility to the TEP problem and allow reduced planning costs. Although the proposed decomposition approach cannot guarantee global optimality, a high level picture of how the network can be planned reliably and economically considering CVSR is achieved.Comment: Accepted by IEEE Transactions on Power System

Reclaiming dependence: personhood, class and the remaking of labour in post-socialist Macedonia

This thesis is primarily an anthropological and historical study of transformations of labour regimes in Macedonia within the context of a changing political economy. This process can largely be situated in the “transition” from a socialist to a market-based economic model; a process which was never only about transforming the “economic” but touched upon every intimate aspect of people’s lives. It is through these changes, and the reconceptualization of what work ought to be about, that we can explore larger questions of class identity, alienation, morality, personhood and the operations of power and social reproduction in contemporary Macedonian society. As such, this thesis is offered as a contribution to the traditional, yet, in the case of Macedonia, under-researched, themes of social and economic anthropology. My primary fieldsite and object of investigation, is the small township of Shtip, in eastern Macedonia, where I investigate the changing role and social status of industrial workers in the national economy, and the everyday working lives of garment labourers in one of Shtip’s largest garment factories. The historical chapters of this thesis analyse the making of an industrial working class within socialist Yugoslavia, and the subsequent attempts at unmaking the values, social relations and forms of personhood, that grew up within the specifics of Yugoslav socialism. I approach “class” through the indeterminate interplay of social, cultural and economic factors, and highlight the enduring cultural importance of embedded, relational forms of personhood. As I move towards more current events, and particularly the ethnographic chapters, I focus more strongly on the responses of industrial workers to such changes. I deal not only with specific practices, but also with questions of the “imagination”, or how workers, experience, and reflect on these wider changes in ways that keep open the possibility of rearranging social relations at the work place, and beyond. In doing do, I propose that struggles over the definition of personhood, rather than class conflict, are at the forefront of debates about what work ought to be about. Also, I suggest that the outcome of these struggles has not been to challenge subordination and social inequality in itself, but to challenge the specific kinds of inequality and subject categories introduced by the transition to a neoliberal market economy (Dunn 2004)

Rural Tourism and Regional Development: Case Study of Development of Rural Tourism in the Region of Gruţa, Serbia

AbstractGeographical area of Gruţa, with its intact natural beauty and important cultural and historical monuments, has significant potential for tourism development. Local government is particularly important to tourism development and promotion in several aspects. Respondents, rural hosts from Gruţa region complained of the lack of cooperation on the part of local government. The experimental research comprises three parts; the first part includes a questionnaire that was conducted in regional and local organizations which have a decisive impact on regional economic development and tourism. The second part of the research was focusing on the basic characteristics of rural households owners. The third part includes qualitative research about rural tourist characteristics. Experimental research for this study was performed in the region of Gruţa in Central Serbia, including registered rural households that have participated in rural tourism in the last few years. Results indicate that rural home owners involved in rural tourism are members of the Tourist Organization of Knić, predominantly male, from 40 to 60 years old and they hold secondary school diplomas. The results of the research suggest that an average tourist in Gruţa is at a higher social and cultural level, with medium income and mostly coming from urban areas. This type of tourist is open to typical rural activities including sports, farm works, as well as to enjoying nature and gastronomy

Optimal Allocation of Series FACTS Devices in Large Scale Systems

Series FACTS devices, such as the variable series reactor (VSR), have the ability to continuously regulate the transmission line reactance so as to control power flow. This paper presents a new approach to optimally locating such devices in the transmission network considering multiple operating states and contingencies. To investigate optimal investment, a single target year planning with three different load patterns is considered. The transmission contingencies may occur under any of the three load conditions and the coupling constraints between base case and contingencies are included. A reformulation technique transforms the original mixed integer nonlinear programming (MINLP) model into mixed integer linear programing (MILP) model. To further relieve the computational burden and enable the planning model to be directly applied to practical large scale systems, a two phase decomposition algorithm is introduced. Detailed numerical simulation results on IEEE 118-bus system and the Polish 2383-bus system illustrate the efficient performance of the proposed algorithm.Comment: Accepted by IET Generation, Transmission & Distributio

Improved Gyrator-Capacitor Modeling of Magnetic Circuits with Inclusion of Magnetic Hysteresis

Gyrator-Capacitor (G-C) models of electro¬magnetic devices provide a robust and convenient approach for simulation of a combined power device that consists of magnetic and electric/electronic circuits. The G-C model seamlessly links magnetic and electric/electronic sides of the device in a power invariant fashion which is very useful for integrated system analysis. This paper proposes an improved G-C model that includes hysteresis besides the core saturation for a ferromagnetic circuit. The approach has been applied to model a Continuously Variable Series Reactor (CVSR) with electromagnetic coupling between two circuits, a control dc and a controlled ac circuit. Taking into account the ferromagnetic core nonlinearities, the CVSR behaviour is investigated in terms of induced voltages across the windings and corresponding magnetic flux densities