Wavelet‐based real‐time stator fault detection of inverter‐fed induction motor

Abstract

This work proposes a novel real-time detection scheme for incipient stator inter-turn short circuit fault in voltage sources inverter-fed induction machines. Both non-sinusoidal input voltage and the short circuit fault causes harmonics in the motor stator current and these combined harmonic components complicate the spectral analysis-based diagnosis in inverter-fed motors. Aim of the analysis is to identify the effect of inverter fundamental/switching frequency on early detection and classification of the inter-turn fault. Discrete wavelet transform based analysis is performed on stator current using daubechies1 wavelet and statistical parameter L2 norm has been computed for the detailed and approximate coefficients at different decomposition levels to obtain the most precise feature of fault. Support vector machine-based learning algorithm is used for the accurate classification of the incipient fault. The proposed method is independent of switching and fundamental frequency, the modulation index and mechanical load. Real-time detection is possible even with infinitesimal fault current of 350 mA by the proposed method. The competency of the proposed algorithm is validated using simulation and verified by hardware with VSIfed induction motor drive.

Novel Diagnostic Techniques for Rotating Electrical Machines—A Review

“…In [50], a real-time procedure is presented for the early detection of stator shorts between turns in an IM supplied by a voltage source inverter (VSI). The methodology is based on the fact that both non-sinusoidal input voltage and short circuits cause harmonics in the stator current; this combination of harmonic components complicates the diagnostics based on spectral analysis.…”

A secure and sensitive wavelet transform based technique for stator fault detection in the cases of line‐connected and inverter‐fed induction machines

“…UVS as one of the most challenging problems for online STTF detection in induction machines has been highly considered in recent research [4,30,35,37], while it causes extensive asymmetrical components in the stator currents, which produce harmonics interfering with STTF. Although the effect of UVS is carefully analysed in these investigations, there is no solution provided to discriminate STTF from an UVS condition [30,32,35,37]. Furthermore, the security of the proposed methods against other faults, especially rotor faults, is another important issue in STTF fault detection that is less discussed in articles [26,30], while the rotor faults, including broken rotor bar in SCIM or RTTF in WRIM, will produce some harmonics on stator currents that can interfere with STTF ones.…”

Fault coil location of inter‐turn short‐circuit for direct‐drive permanent magnet synchronous motor using knowledge graph

“…In [16, 17], the negative‐sequence voltage method and voltage residual method are used to detect the fault based on the extra voltage components induced by ISF. In [18], discrete wavelet transform‐based analysis is performed on stator current to detect the ISF. However, these methods cannot provide location information about the fault.…”