An experimental investigation of new electromagnetic field signal for stator asymmetric fault detection of doubly fed induction generators

The paper presents an investigation of a new electromagnetic signal for the diagnosis of the doubly fed induction generator (DFIG). The signal is acquired by using a dedicated sensor located on the bus surface of the DC link in the DFIG system. To demonstrate the feasibility and efficiency of applying this signal in condition monitoring of DFIG, a procedure of diagnosing stator asymmetrical fault is shown. Physical phenomena of the defect are first analysed to obtain the harmonic signature. Afterwards, the benchmark will be processed with the defect to extract the specific signature in the DC bus magnetic field. The experiment results show that the proposed signal can be efficiently applied in the diagnosis of wind power generators.