电流残差谐波谱幅值调制的双馈感应发电机匝间短路诊断方法

To address the issuc of intcr-turn shorl cireuits in the Stator or rotor windings of doubly fed induction generators (DFIG), which are caused by insulation degradation and result in the generation of sideband harmonics ncar the fundamental frequency and harmonics that are casily submerged by noisc intcrfcrcncc, making it difficult to effectively distinguish between fault characteristic frequencies and interference components, a method for diagnosing DFIG inter-turn short cireuit faults based on current residual harmonic spectrum amplitude modulation is proposed. Firstly, by performing an S-transform on the zero-sequence current of the DFIG to obtain its time frcquency domain phase and amplitude, the phase is corrected and the amplitude is modulated to different degrees. Subsequently, the modulated current residual harmonic spectrum is calculated. Finally, experimental verification is conducted on a 100 kW doubly fcd induction generator winding short circuit fault Simulation platform. The rcsults dcmonstrate that the proposed method can effectively extract fault characteristic frequencies, with errors of 0. 083% and 0. 117% for the extracted Stator current fault characteristic frequencies (1 — 2.v)/s and (1 + 2s) fB during rotor winding intcr-turn short circuit faults, respectively, exhibiting higher aecuraey in the extracted fault characteristic frequency components. This method can better detect the characteristic frequencies of DF1G intcr-turn short cireuits, effectively extracting and distinguishing between fault characteristic components and interference components.