An Imbalance Fault Detection Approach based on Differential Concordia Transform for Marine Current Turbine

Marine current turbine (MCT) has gradually entered and contributed to world energy resources. However, MCT imbalance fault often occurs due to the blades are attached by marine biological growth or marine pollutants, and this imbalance fault will disorder the stator current or output power of generator. In this paper, a novel method based on Differential Concordia transform (DCT) for MCT imbalance fault detection is presented. The goal of this method is to provide a sensitive and robust fault indicator to detect the imbalance fault of MCT under wave and turbulence. The proposed method acquires the 3-phases stator current from the generator and using Concordia transform (CT). Then, reconstruct the Concordia transform components (CTC) to gain the Concordia transform modulus (CTM) and calculate differential to remove trend. Finally, the frequency spectral analysis is used to monitor the condition of blade. A 230-W prototype experimental study verified that the proposed method provides an effective fault indicator for MCT imbalance fault.