Current Unbalance Monitoring In Four-Wire System Based on Fuzzy Logic
Achmad Marzuki,
Bangbang Hermanto,
Wawan Heryawan,
Abu Bakar
Issue:
Volume 7, Issue 1, June 2023
Pages:
1-9
Received:
20 January 2023
Accepted:
13 March 2023
Published:
15 March 2023
Abstract: The daily consumption profile of electric power is different for each electrical customer, which is random and unpredictable, especially in residential, commercial, and educational areas, which are dominated by single-phase electrical loads. The abundance of this one phase load can enhance the current unbalance of the three-phase four-wire system, and will cause several other power quality problems e.g., Increasing Neutral current, displacement of neutral point, Increasing heating in one phase and losses in distribution network. However, the PIUR (Phase current unbalance rate) value as one of indicators of power quality must not exceed the threshold recommended by the NEMA standard, which is a maximum of 30%. For this reason, this paper proposes a current unbalance monitoring based on Fuzzy Logic to produce an unbalance quality (excellent, good, moderate, bad, and poor) that can be monitored by electric customers globally. The unbalance quality is very useful for electric customers to rearrange their single-phase load installation so that the power quality indicator value is expected to be within the allowable range. In addition, this prototype (proposed system) is also able to provide great convenience for electric customers to monitor the changes of profile uses of loads, and at the same time can detect the emergence of disturbances early that may occur in each phase.
Abstract: The daily consumption profile of electric power is different for each electrical customer, which is random and unpredictable, especially in residential, commercial, and educational areas, which are dominated by single-phase electrical loads. The abundance of this one phase load can enhance the current unbalance of the three-phase four-wire system, ...
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Comparative Analysis of Surface Refractivity Variations in the Sahel and Coastal Zones of Nigeria
Yusuf Babatunde Lawal,
Joseph Babatunde Dada
Issue:
Volume 7, Issue 1, June 2023
Pages:
10-18
Received:
15 April 2023
Accepted:
4 May 2023
Published:
10 June 2023
Abstract: Variation in Surface Refractivity N is largely influenced by changes in some meteorological parameters such as air temperature, relative humidity, and pressure. These parameters are more accurate when measured locally due to their temporal and spatial variations. The research studies and verifies the contributions of the dry and wet term components of surface radio refractivity. The research focuses on the comparison of surface refractivity variations in two geoclimatic zones of Nigeria. The study reveals that the Sahel and Coastal zones have dissimilar distinct weather conditions and consequently diverse variational pattern of their surface refractivities diurnally and seasonally. The diurnal values of surface refractivity vary moderately on typical sunny days with average values of about 345-391 N-units and 275-314 N-units in the Coastal and Sahel respectively. Wider daily variations were observed during the rainy season in both geoclimatic zones due to frequent rainfalls, especially in the Coastal Stations. The average daily refractivity in the Coastal and Sahel during the rainy seasons are 339-390 and 311-384 N-units respectively. Analysis of the results obtained indicates that the annual mean of the ITU-R recommendation underestimates surface refractivity by 11-15% across the coastal stations and by 5-10% across the Sahel zone. The derived values for each station would be useful for radio engineers in the design and optimization of terrestrial radio links.
Abstract: Variation in Surface Refractivity N is largely influenced by changes in some meteorological parameters such as air temperature, relative humidity, and pressure. These parameters are more accurate when measured locally due to their temporal and spatial variations. The research studies and verifies the contributions of the dry and wet term components...
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