Current Unbalance Monitoring In Four-Wire System Based on Fuzzy Logic

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.