Abstract:
Currently there is an ongoing deregulation of the power system that has given a new face to the power system by introducing the Distributed generators (DGs) into distribution systems, leading to a bi-directional power flow. One of the major challenges of this system is unintentional islanding of part of the grid. If the occurrence of an unintentional islanding condition is not detected as soon as it occurs or it is completely not detected, it can lead to a total blackout in the entire power system.
To address this challenge, this study is broken into two parts; part one is based on islanding detection of a rotating machine based DGs by using wavelet transform (WT) and fuzzy logic (FL) algorithm. From this analysis, it was observed that there was a quick response to islanding detection due to the changing of the point of measuring of the current signals from the usual PCC to just after the utility circuit breaker. It took 0.2 seconds for this algorithm to detect the occurrence of the island. This is because the islanding detection time is not affected here by the circuit breaker operation time. Thus, making the detection process faster hence the reduction in NDZs in this system.
The second part of this study involved finding the optimal load to be shed and the selection of the buses to be shed using the ABC algorithm. This algorithm was tested on a fourteen-bus system and the obtained result for this system was analyzed and it was satisfactory to draw concrete conclusions. In comparison with other methods of optimization, the proposed algorithm can obtain better optimal solution than many other methods with a fast-computational manner, especially for large-scale systems. Therefore, the proposed ABC algorithm can be a favorable method for solving optimization and prioritization problems in power systems.
