Background: Distributed Sustainable Energy Generation (DSEG) has become a leading
trend in modern R&D to achieve practical, financial, and environmental benefits. With respect to the
power system, the benefits are minimization of power failures, enhancement of energy quality &
reliability, congestion relief, and smart/micro grid demand response. The widespread use of modern
technologies encourages the use of DSEG for safe power production and power loss reduction. Besides,
it also poses new challenges such as optimal placement of relays, protection device settings,
and voltage control problems in power systems.
Among various solutions reported in the literature, a widely accepted solution seems to be the deployment
of Fault Current Limiter (FCL) to minimize DSEG impacts. However, FCLs are an expensive
option to restore relay coordination. The adaptive protection scheme provides benefits to the
smart grid's advanced features and serves as an efficient solution to address new DSEG and FCL
Objectives: This paper presents an extensive review of the effect of DSEG on distribution systems
from the safety point of view, different optimization techniques used for adaptive protections, optimal
relay coordination, and merits & demerits of FCL.
Methods: The paper discusses various recent optimization and hybrid optimization techniques used
for solving the Optimal Relay Coordination model (ORC). Adaptive and FCL based non-adaptive
techniques are also discussed to solve this model. An attempt has also been made to present a comparative
study of various optimization techniques in tabular form, considering different bus models
and their outcomes.
Results: Various optimization techniques have been used by the researchers to solve significant issues
of DSEG impacts on the distribution grid.
Conclusion: Comparative study of these techniques shows that Water cycle optimization, hybrid
whale-GWO and GSA-SQP algorithms give better results in solving the ORC problem. FCL based
non-adaptive technique was found better as compared with adaptive techniques because a greater
number of DGs can be integrated on a grid with less complexity.