Adaptive Overcurrent Protection Scheme with Zonal Approach for a Stand-Alone Renewable-based Microgrid

This paper presents the design of an adaptive overcurrent protection scheme with a zonal approach for a standalone renewable-based microgrid with various generation capacity, generation type and loading conditions. Supply and loading conditions in the network are constantly monitored by a control system which in turn communicates with coordinated relays on each feeder in order to adapt to any changes in supply or loading conditions. DIgSILENT Powerfactory was used to design the microgrid and capture all nominal and overcurrent levels for all test cases and Matlab was used to implement the proposed protection scheme. After development, analysis and simulation, the resulting protection scheme proved to have the ability to maintain its functionality for all the tested loading and supply conditions.