Resolution evaluation of ultrasonic diagnosis tools for electrical insulation devices and the detection of electrical trees

Ueno, Hideki; Walter, Philipp James Ludwig; Cornelissen, Christian; Schnettler, Armin

doi:10.1109/tdei.2007.302893

Cited by 20 publications

(10 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where D is the diameter of a transducer and λ is the wavelength [37]. A range of 1-3 N has a higher sensitivity because it belongs to the non-diffusion zone of acoustic waves.…”

Section: Transducermentioning

confidence: 99%

An Ultrasonic Pulse-Echo Method to Detect Internal Defects in Epoxy Composite Insulation

et al. 2019

View full text Add to dashboard Cite

Voids or cracks in basin insulators inside a GIS (gas-insulated metal-enclosed switchgear) could trigger partial discharges or surface flashover under electrical stresses, threatening safe GIS operation. For this paper, some epoxy composite specimens were made from similar materials and manufacturing processes to make 252 kV GIS basin insulators. Some voids with different diameters or cracks with different diameters and orientations were artificially made in the specimens with different thicknesses. An ultrasonic pulse-echo system was set up, and ultrasonic tests were carried out on the specimens with voids or cracks. A method to calculate the depth of a defect was proposed by the propagation time of defect reflected waves. The results showed that a depth of 50 mm, a diameter φ of 2 mm void, and a diameter φ of 1 mm crack in epoxy composite insulation were detected by the ultrasonic system using a 1 MHz transducer.

show abstract

“…where D is the diameter of a transducer and λ is the wavelength [37]. A range of 1-3 N has a higher sensitivity because it belongs to the non-diffusion zone of acoustic waves.…”

Section: Transducermentioning

confidence: 99%

An Ultrasonic Pulse-Echo Method to Detect Internal Defects in Epoxy Composite Insulation

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Ultrasound imaging techniques consist of sending ultrasound pulses to an area of interest and capturing the reflected signals coming from the interfaces where differences in acoustic impedance exist. It is a non-destructive method able to detect and characterize flaws in insulation [41][42][43]. Moreover, this technique has been applied for the detection of electrical trees [42,44,45].…”

Section: Ultrasoundmentioning

confidence: 99%

“…It is a non-destructive method able to detect and characterize flaws in insulation [41][42][43]. Moreover, this technique has been applied for the detection of electrical trees [42,44,45]. In its application, the transducer which sends and receives the ultrasound signals, and the sample are normally immersed into a water tank in order to obtain better transmission avoiding mismatching of acoustic impedances.…”

Section: Ultrasoundmentioning

confidence: 99%

See 1 more Smart Citation

Imaging and analysis techniques for electrical trees using X-ray computed tomography

Schurch

Rowland

Bradley

et al. 2014

IEEE Trans. Dielect. Electr. Insul.

View full text Add to dashboard Cite

Electrical treeing is one of the main mechanisms of degradation in polymeric high voltage insulation, a precursor of power equipment failure. Electrical trees have been previously imaged mostly using two-dimensional imaging techniques; thereby loosing valuable information. Here we review the techniques that have been previously used and present the novel application of X-ray computed tomography (XCT) for electrical tree imaging. This non-destructive technique is able to reveal electrical trees, providing a threedimensional (3-D) view and therefore, a more complete representation of the phenomenon can be achieved. Moreover, taking virtual slices through the replica so created brings the possibility of internal exploration of the electrical tree, without the destruction of the specimen. Here, laboratory created electrical trees have been scanned using XCT with phase contrast enhancement, and 3-D virtual replicas created through which the trees are analyzed. Serial Block-Face scanning electron microscopy (SBFSEM) is shown to be a successful complementary technique. Computed tomography enables quantification of electrical tree characteristics that previously were not available. Characteristics such as the diameter and tortuosity of tree channels, as well as the overall tree volume can be calculated. Through the cross-section analysis, the progression of the number of tree channels and the area covered by them can be investigated. Using this approach it is expected that a better understanding of electrical treeing phenomenon will be developed.

show abstract

“…The specimens were made of low-density polyethylene, which was compressed and moulded into blocks to observe the growth of defects. Ultrasound imaging is also used for the inspection of insulation [8,9]. Ultrasound synthetic aperture imaging can successfully detect 1-mm-size faults within the XLPE insulation of a cable [10].…”

Section: Introductionmentioning

confidence: 99%

Terahertz Non-Destructive Testing and Imaging of High-Voltage Cables

Zhang

Jia

et al. 2022

Front. Phys.

View full text Add to dashboard Cite

The evaluation of the internal defects in high-voltage cross-linked polyethylene cables is highly crucial for the security and reliability of power transmission. Here, a terahertz (THz) frequency-modulated-continuous-wave non-destructive testing (NDT) imaging system is used to demonstrate the non-contact detection of a high-voltage cable (35 KV). Combined with linear scanning and axial rotation, the three-dimensional (3D) data of the columnar target is acquired, and a 3D perspective image is reconstructed. The correspondence between the target in the real space and image space is determined to accurately show the internal spiral structure and strand number of metal wires. The results indicate that prefabricated air and water holes in the polyethylene insulation layer can be displayed. Furthermore, feature defect signals are automatically classified and recognised by combining the principal component analysis dimension reduction method and the support vector machine classification method, which can predict abnormal defects more efficiently in mass data. These results provide technical guidance for the non-contact NDT and visual evaluation of the internal state of detected cable targets.

show abstract

Resolution evaluation of ultrasonic diagnosis tools for electrical insulation devices and the detection of electrical trees

Cited by 20 publications

References 10 publications

An Ultrasonic Pulse-Echo Method to Detect Internal Defects in Epoxy Composite Insulation

An Ultrasonic Pulse-Echo Method to Detect Internal Defects in Epoxy Composite Insulation

Imaging and analysis techniques for electrical trees using X-ray computed tomography

Terahertz Non-Destructive Testing and Imaging of High-Voltage Cables

Contact Info

Product

Resources

About