Performance response tests on a multivariable fuzzy rule-based relay for short circuits in AC micro-grids

摘要

This paper presents the results of offline and online performance tests on a new multivariable fuzzy rule-based (MFR) relay for AC micro-grids. The relay is based on measurement of four critical parameters (P, Q, V and I) and fuzzy logic implementation of rules framed on the basis of these parameters. The online test is performed by embedding the relay in a micro-grid test bed capable of grid-connection. The offline test is performed by simulating High, Normal and Low states of the four parameters using proper combination of digital signal sources to implement short circuits (SCs) in SIMPOWERSystems? software. In both offline and online tests, the faults simulated are standard SCs in the utility and micro-grid. The results of both offline and online tests are similar, and show that the MFR relay outputs logic 1 during SC faults. The relay also outputs logic 0 before and after the SC faults for both offline and online tests.