The present study presents a new islandingdetection method based on variational mode decomposition (VMD). In the method,the VMD transform of the voltage at point of common coupling is calculated, andthen based on the decomposed modes, an islanding detection index fordistinguishing between islanding and normal conditions will be derived.Pursuing this objective, the measured voltage is decomposed into four modes,and a new islanding detection index will be derived from their energy and theirvariations. Then, thresholds will be adjusted based on values of proposed indexin various conditions on normal and islanding operations. The proposedalgorithm decomposes the measured signal into a predetermined number ofintrinsic modes around central frequencies; the method is insensitive to thenoise and sampling frequency. To validate the method, a distribution networkhas been simulated in PSCAD/EMTDC, and the algorithm is tested on a variety ofislanding and normal circumstances. The results illustrate desired performanceof the proposed algorithm for conditions such as motor, nonlinear, and largeload switching; as normal condition; and islanding condition with a variety ofpower mismatches between local load and distributed generation. The resultsdemonstrate the desired performance of the method with respect to both speedand accuracy.
Cite this article as: Salimi S, Koochaki A.An Effective Method for Islanding Detection Based on Variational ModeDecomposition. Electrica, 2019; 19(2): 135-1145.