Reliable and Robust Inter-turn Short-Circuit Fault Detection in PMSG without confusion with Healthy Operating Under Load Unbalance

This paper proposes an efficient symmetrical component based-method to detect and diagnose accurately an incipient inter-turn short circuit (ITSC) fault in the permanent magnet synchronous generator (PMSG) without any ambiguity, in the aim to increase the reliability of the machine. However, since the presence of negative sequence voltage component can be due to an ITSC fault as well as due to load unbalance in healthy operating mode, false alarm can be generated. To handle with this issue, this papier proposes an effective, robust and new fault diagnosis indicator capable to discriminate without any ambiguity ITSC faults from load unbalance. Therefore, in this paper, three pertinent indicators have been developed: 1) the magnitude of the negative sequence voltage V2 as an efficient indicator to detect any unbalance in the machine. 2) the phase shift Δφ
2
between the negative sequences of the machine voltage and current as a new robust discriminative indictor to distinguish between faulty mode and healthy operating with load unbalance and 3) the phase angle φ
V2
of the NSV as a robust indicator for the identification of the faulty phase in case of ITSC fault and the unbalanced phase in case of load unbalance.