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Podział środków inwestycyjnych na rozwój sieci rozdzielczych przy zastosowaniu metody taksonomicznej

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W referacie przedstawiono algorytm służący do podziału środków inwestycyjnych w przedsiębiorstwach dystrybucyjnych przy zastosowaniu metody taksonomicznej Hellwiga. Metoda ta pozwala rozdzielić środki finansowe przeznaczone na rozwój i modernizację sieci oraz przyłącza pomiędzy rejony energetyczne. Abstract. The paper presents an algorithm, serving to divide the investment means in the distributive companies with use of the Hellwig taxonomic method. The method allows to split the investment means, destined for the power network development and modernization, between the organizatory divisions of a distributive company. (Division of the investment means for the power network development with use of the taxonomic method) Słowa kluczowe: ekonometria, sieci rozdzielcze, koszty Keywords[...]

Electrical energy losses in the time zones

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W artykule pokazano zasady podziału strat napięciowych, obciążeniowych i handlowych na strefy czasowe z uwzględnieniem przepływów energii w sieciach. Straty energii w strefach czasowych są obliczane według czasów odpowiednich dla danego rodzaju strat, przy znanych stratach bilansowych. Podano podział strat energii dla stref czasowych w sieci dystrybucyjnej jednej ze SD. (Straty energii elektrycznej w strefach czasowych) Abstract. The paper presents the rules, making possible - with regard of the energy flows in the network - dividing of the voltage, load, and commercial energy losses into the assigned-to-the-particular-time-zones parts. The energy losses in the time zones are being calculated - under the known balance losses - according to the times corresponding with the particular categories of the losses. The division of the energy losses into the time zones has been demonstrated for an exemplary Distribution Company network. Słowa kluczowe: sieć dystrybucyjna, straty energii elektrycznej, taryfy Keywords: distribution network, electrical energy losses, tariffs Introduction The problem of calculating the duration of peak loads and of maximal losses in the time zones is relatively new. Meters measuring electrical energy and power consumption in the time zones are not installed with every consumer. The computer programme used by a number of distribution companies for calculating losses in distribution networks computes the total loss in 24-hour periods. It is sufficient for loss analysis, however, for the sake of developing energy tariffs the detailed knowledge of loss distribution among the time zones is necessary. Obviously, the division of loss into time zones cannot be proportional to the zone duration, losses are not distributed equally. A method of dividing losses among the time zones with the consideration of the flow structure in the low-voltage, medium-voltage and 110 kV networks will be discussed in this paper. It is ass[...]

Profitability analysis of investment projects in distribution networks DOI:10.15199/48.2019.08.04

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Introduction The most important characteristic feature that distinguishes investment in the power sector from other branches of industry is that it is a long-lasting and complicated process. This is related to a relatively long life of the elements of the power system. Polish distribution networks include elements which have been heavily exploited and require replacement or modernization [1-3]. Another feature typical of investment in the power industry is a relatively long period of return on invested capital. Besides, the capital expenditure and cost of investment are also relatively high. Table 1 presents the age structure of selected elements of the power grid for the five biggest Polish distribution companies (OSD) as of end of 2017 [4]. Table 1. Age structure of selected network elements [%] Network elements > 40 years old 25-40 years old 10-25 years old < 10 years old HV overhead 42 34 15 9 HV cable 0 3 17 80 HV/MV substations 30 33 20 17 HV/MV transformers 19 33 19 29 MV overhead 37 39 17 7 MV cable 16 24 28 31 MV/LV substations 28 32 22 19 MV/LV transformers 15 29 25 31 LV overhead 31 35 21 13 LV cable 13 25 31 31 The necessity of making investment in the power industry is motivated mostly by the fact that the transmission and distribution networks include worn-out elements and are largely ineffective, with high loss and low reliability. About 25% of the network equipment is more than 40 years old, and another 25-30% is over 25 years old. The directions of development for the distribution network are as follows [5-10]: - reducing energy loss in distribution transformers and networks, - modernizing and expanding the 110 kV distribution network and networks of lower voltages with a view to the following: o minimizing technical and commercial loss, o increasing reliability, o expanding the network in order to offer services to a greater number of customers, o connecting renewable en[...]

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