Acoustic emission: its techniques and applications

Jha

Materials Science and Technology

2014

A systematic study has been undertaken to correlate the changes in acoustic emissions during tensile deformation of sensitised AISI type 304 stainless steel. Samples of a typical 304 stainless steel were sensitised at 700°C for 4, 14 and 24 h after being austenised at 1050°C for 30 min. AE signals were recorded during tensile test by using two sensors with 125 kHz resonant frequency. The results showed significant change in generation of AE during tensile deformation of sensitised AISI 304 stainless steel in compare to solution annealed material. This type of behaviour could be attributed to the microstructural changes in the sensitised specimens especially formation of continuous Cr23C6 carbides on grain boundaries which lead to increase in shearing by dislocations.

Section: Resultsmentioning

confidence: 99%

Acoustic emission study of deformation behaviour of sensitised 304 stainless steel

Jha

Materials Science and Technology

2014

“…Figure 8a illustrates three distinct UHF sensors that are suitable for the purpose of PD detection on both power transformers and gas-insulated switchgear. Conventionally, the three types of sensors utilized for PD detection, according to reference [110], are disc-type, monopole-type, and spiral-type sensors. Recent research has revealed that these sensors accumulate a significant amount of energy, demonstrating their excellent sensitivity in detecting emitted signals [110].…”

Section: Combinational Methodsmentioning

confidence: 99%

“…Conventionally, the three types of sensors utilized for PD detection, according to reference [110], are disc-type, monopole-type, and spiral-type sensors. Recent research has revealed that these sensors accumulate a significant amount of energy, demonstrating their excellent sensitivity in detecting emitted signals [110]. Meanwhile, Figure 8b depicts a capacitive coupler used in a high-voltage cable for PD detection.…”

Section: Combinational Methodsmentioning

confidence: 99%

Detection Method of Partial Discharge on Transformer and Gas-Insulated Switchgear: A Review

Faizol,

Zubir,

Saman

et al. 2023

Applied Sciences

The detection of partial discharge (PD) activities in high-voltage equipment can be conducted according to several mechanisms of signal detection, including electromagnetic wave signal detection, acoustic signal detection, chemical reactions, electrical signal detection, and optical emission detection. Recently, multiple methods of detection and localization of partial discharge activities, which occurred in power transformers and gas-insulated switchgear (GIS), have been proposed to monitor the health condition of high-voltage equipment, especially when the awareness regarding preventive maintenance has been emphasized at the industrial level and among electrical providers. In aligning the needs of the industrial sector and the improvement of PD-detection methods, this manuscript focuses on reviewing the current practice methods for the detection and localization of PD signals in high-voltage equipment, comparing their efficacy, and summarizing the future direction of research work-related methods of PD detection. The comparative reviews are discussed in terms of the mechanism of PD signal detection, indication parameters, calibration techniques, and the advantages and limitations of each method of PD measurement in detail.

“…They are the disc-type, monopole-type, and spiral-type. The disc-type, monopole-type, and spiral-type sensors can provides the greatest energy accumulation in the laboratory test, which indicates that the sensors have the high sensitivity for detecting radiated signals [20]. Figure 3 shows a capacitive coupler for partial discharge detection in (a) (b) (c) Fig.…”

Section: Sensors For Electrical Quantity Measurementmentioning

confidence: 99%

Review on partial discharge detection techniques related to high voltage power equipment using different sensors

et al. 2014

When operating an equipment or a power system at the high voltage, problems associated with partial discharge (PD) can be tracked down to electromagnetic emission, acoustic emission or chemical reactions such as the formation of ozone and nitrous oxide gases. The high voltage equipment and high voltage installation owners have come to terms with the need for conditions monitoring the process of PD in the equipments such as power transformers, gas insulated substations (GIS), and cable installations. This paper reviews the available PD detection methods (involving high voltage equipment) such as electrical detection, chemical detection, acoustic detection, and optical detection. Advantages and disadvantages of each method have been explored and compared. The review suggests that optical detection techniques provide many advantages in the consideration of accuracy and suitability for the applications when compared to other techniques.