Hardware-In-Loop Evaluation of Microgrid Protection Schemes

Distributed energy resources are becoming more common in distribution systems. Higher energy prices and increased interest in alternative energy sources are two of the driving forces behind this trend. Local utilities, however, anticipate very serious distribution system protection problems resulting from high penetration of these resources.

The microgrid concept has been proposed as a possible solution to integrating distributed energy resources without adversely impacting the distribution system. Protection schemes have been proposed to work within this microgrid structure, but very little testing with real hardware is available. Without a practical solution for microgrid protection, backed by extensive studies, microgrids are unlikely to receive wide acceptance.

This thesis outlines modeling of microgrids for protection testing using a real time digital simulator. In addition, the construction of a low voltage, low power, hardware-in-loop test bed using relays and an automation controller is detailed. The results of testing possible microgrid protection schemes using this apparatus are presented along with conclusions and suggestions for future work.