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Vol. 25 (2022 year), No. 4, DOI: 10.21443/1560-9278-2022-25-4

Akhmetshin A. R., Soluyanov Yu. I., Fedotov A. I., Chernova N. V., Soluyanov V. I.
Calculation of specific electrical loads of residential buildings based on actual measurements

Updating the development of specific electrical loads of residential buildings of clusters 1 (up to 5 floors) and 2 (6–11 floors) based on actual measurements (with amendments to the Code of Rules 256.1325800.2016 "Electrical installations of residential and public buildings. Design and installation rules") contributes reducing the cost of technological connection in residential construction, as well as reducing the actual unused "locked power" at the same time as reducing electricity losses in power transformers. In the course of the study, an analysis has been made of the actual electrical loads of residential buildings in Moscow for the periods from November 1 to November 30, 2021 and from December 25, 2021 to January 31, 2022. The number of the studied sample for cluster 1 is 91 houses, for cluster 2 – 58 houses. When determining the maximum specific power of a sample set of multi-apartment residential buildings in Moscow in clusters 1 and 2, an average value and a confidence interval have been established, which "covers" the average of the general population with a probability of 95 %; a comparative analysis of the actual specific electrical loads of a residential building with the loads given in the Code of Rules has been carried out. Based on the results of statistical processing of a sample of multi-apartment buildings in clusters 1 and 2, the dependence of the maximum specific power on the number of apartments in a residential building has been determined with a trend line that clearly illustrates the trend in the studied dependence.

(in Russian, стр.10, fig. 8, tables. 3, ref 24, AdobePDF, AdobePDF 0 Kb)

Vol. 26 (2023 year), No. 4, DOI: 10.21443/1560-9278-2023-26-4

Fedotov A. I., Vagapov G. V., Abdullazyanov R. E., Fedotov E. A.
The single phase-to-ground fault location calculation method based on limited information on the distribution of zero-sequence voltages on the tree-structured feeder

One of the key goals in the overhead power lines at the isolated neutral system 6–10–35 kV is topographic search area limitation for a single phase-to-ground (SPG) fault. This will ensure reliability improvement warranty and continuity of power supply. No fault founded in time can lead to failure of electrical equipment. Faults can initiate a ground fire in dry-weather period, which requires preventive shutdown of power lines with subsequent economic damage to power supply organizations. The paper proposes the use of emergency mode parameters, namely, zero-sequence voltages, in order to determine the faults locations in a calculated way. The need for additional installation of measuring voltage transformers at terminal substations is associated with some financial costs. In this regard, the possibility of their limited use is being considered. It has been shown that in this case the emergency section can be localized with accuracy down to the tap if there are no measuring voltage transformers on it. To calculate the SPG location, a mathematical model of lines with distributed parameters has been used. Signals at higher harmonics (HH) generated in the electrical network by arc faults, are considered useful. Full-scale experiments show the HH presence also during electrical contacts of wires with metal structures. The high frequency of the signal causes a significant change in voltage along the length of the line, which increases the accuracy of calculations. The use of zero sequence voltages promotes detuning from the influence of substation load. An algorithm has been developed for performing calculations to determine the location/area with a ground protection zone on a tree-structure feeder.

(in Russian, стр.15, fig. 13, tables. 0, ref 33, AdobePDF, AdobePDF 0 Kb)