An Automatic Diagnosis of an Inverter IGBT Open-Circuit Fault Based on HHT-ANN

Abstract

The main objective of this paper is to propose a method that contributes to the automatic diagnosis of the IGBT open-circuit fault of an inverter for detecting and localizing the fault using the stator current spectral analysis technique. The proposal focusses on the use of the combination of signal processing and artificial intelligence techniques for the detection and localization of the fault. The proposed diagnosis method begins first by using the Hilbert-Huang transform (HHT) to detect the harmonic characterizing the fault based on the complete empirical ensemble mode decomposition (CEEMD) of the three-stator currents (i_as, i_bs, i_cs ). The CEEMD provides the intrinsic mode function (IMF) which contains information of the IGBT open-circuit fault. For the exact choice of the IMF, a statistical study based on the calculation of the root mean square values (RMS) is carried out for each IMF. The IMF choice depends on the condition that the RMS values of the inverter upper IGBTs are always lower than the RMS values of the complementary ones. The results obtained can be seen to respond well to the RMS condition and the spectral envelope of the IMF₁ makes it possible to detect the harmonic characterizing the inverter IGBT open-circuit fault. The proposed diagnosis method then moves to the use of the artificial neural network (ANN) to localize the faulty IGBT. The results obtained using the proposed method are validated experimentally and demonstrate well their effectiveness with a very high classification rate.