An open-circuit fault diagnosis method and experimental platform for anpc three-level inverters

Abstract

The invention relates to a method for diagnosing open-circuit faults of ANPC three-level inverters. , the voltage of the lower bridge arm, and the collected signal is sent to the host computer of the experimental platform; the host computer extracts the wavelet packet energy spectrum entropy as the initial feature vector, and then performs dimensionality reduction processing on the data, as the final feature vector, according to 2: 1 ratio is divided into training data and test data; establish wavelet neural network WNN, use Adam algorithm to optimize WNN training algorithm, use training samples to train WNN, and save the trained WNN model; use test data to test WNN model, Analyze diagnostic results. The present invention shows through the diagnosis result of the ANPC three-level inverter experimental platform that the method can reach 98.46% accuracy, and the performance is better than the traditional neural network and the unoptimized wavelet neural network.

Description

technical field [0001] The invention relates to the technical field of fault diagnosis of three-level inverters, in particular to a method and a system for diagnosing open-circuit faults of ANPC three-level inverters. Background technique [0002] Compared with traditional two-level inverters, three-level inverters work more stably and reliably, and have been widely used in industrial equipment. However, due to the unbalanced power device loss of diode-clamped (Neutral-Point Clamped, NPC) three-level inverters, Professor T. Bruckner and others proposed Active Neutral-Point Clamping (Active Neutral-Point Clamping) at the 2001 IEEE-PESC meeting. Point Clamped (ANPC) three-level inverter topology, which has the characteristics of high power, large capacity and device loss balance, has been widely recognized. However, the three-level inverter increases the number of switching devices IGBT, which makes the circuit structure complex, and the failure of any IGBT may cause the inve...

AI Technical Summary

Problems solved by technology

This diagnostic method has certain practicability, but the method is relatively complicated, and an accurate mathematical model needs to be established for the circuit. If the circuit is slightly changed, the model can no longer be used.

[0006] Compared with the NPC inverter, the ANPC three-level inverter has added power devices, which further increases the difficulty of diagnosis. The existing diagnosis methods are difficult to operate on the ANPC three-level inverter.

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