The article describes research into the use of acoustic emission elastic waves (AE) for diagnosing insulated-gated bipolar transistors (IGBTs). Currently used in many modern shipboard power electronic systems, IGBTs are crucial components required to operate with extreme reliability. The acoustic emission elastic waves method was used to determine the acoustic signals of switching transistor and can be used to monitor early stages of damage. Transistor diagnostics makes use of selected frequency descriptors of AE and appropriate signal analysis.

The article presents the results of tests related to failure analysis and finding ways to diagnose used semiconductor elements, among others, in power electronics converter systems on vessels and offshore facilities (drilling and production rigs and wind turbines). Diagnostic relationships were found between the temperature change in the above systems and the signals generated in the form of elastic waves of acoustic emission. The authors confirmed the influence of the transistor’s working temperature on its amplitude-frequency spectrum of acoustic emission signals emitted. The range of ‘safe temperatures’ was considered which means temperatures that do not directly affect the damage of the component.

This work is an introduction of acoustic emission (AE) signals used in order to detect the malfunction of selected semiconductor elements. The authors proposed the use of internally generated signals (elastic waves) of acoustic emission leading to the detection of the pre-fail state of switching IGBT transistors. The analysis of the AE signals allows the creation of a reference pattern of properly working transistors and at the same time the identification of abnormal signals, which are generated by a defective element. Unlike many papers, this article shows experimental results demonstrating a comparison of undamaged, properly working and defective IGBT transistors which can be used, for example, as a reference for diagnostic tools. Analysis of the signal in the frequency domain obtained from the faulty transistor (overheated or with damaged casing) shows the presence of additional frequencies which can indicate the imminent occurrence of critical damage.

Many recent researches are focused on the diagnostic methods allowing determination of the condition of working semiconductor components (power transistors, diodes etc.). As any solid material under stresses (mechanical, temperature and electrical) the semiconductors are generating elastic waves in the case of changing conductivity state. Based on the results of experimental research, a correlation can be observed between the transition between the on and off states of a single IGBT transistor and the emitted acoustic signal. Acquisition of acoustic emission signals was obtained with use of a wide band acoustic emission sensor. The received signal initially was prepared by AD input card with amplifier and then were recorded by means of a computer software. Acquired data were exported the to a file, which enabled further processing of the measured signals. The aim of the study was to determine the acoustic emission background signal coming from switching IGBT transistor and preparation of frequency response. The results of analysis will be used as a reference point for a further investigation of early-stage faults of semiconductors elements.

The article presents the results of tests related to failure analysis and finding ways to diagnose used semiconductor elements, among other, in power electronics converter systems on vessels and offshore facilities (drilling and production rigs, wind turbines). Diagnostic relationships were found between the temperature change in the above systems and the signals generated in form of elastic waves of acoustic emission.