Dispersion and PD detection in shielded power cable [Feature article]

Shu, E.W.; Boggs, S.A.

doi:10.1109/mei.2008.4455500

Cited by 27 publications

(12 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The phase difference ∆Φ between signals x 2 (t) and x 1 (t) in the frequency domain is shown in (3), where Ω is a non-linear term owing to multi-path propagation. Term Ω is detailed in (4), where the coefficient ρ is the effective peakvalue of the echo signal shown in (5). The PD signal x 0 (t) is assumed to be a gaussian pulse with standard deviation σ 0 .…”

Section: Cablementioning

confidence: 99%

“…The PD signal x 0 (t) is assumed to be a gaussian pulse with standard deviation σ 0 . The effect of the echo signal is reduced because of both, attenuation (α 0 ) and dispersion (β 2 ), as shown in (5).…”

Section: Cablementioning

confidence: 99%

“…In medium voltage cables both, the high frequency behaviour of the semiconductor layer [5], and the effects of aging [6], make each frequency component of the PD signal travel with a different propagation velocity. This effect, called dispersion, spreads PD pulses as they travel along the cable [4] and, as a consequence, their bandwidth is reduced.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Dispersion and Multi-Path Propagation in Partial Discharges Location

2020

View full text Add to dashboard Cite

Section: Cablementioning

confidence: 99%

Section: Cablementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Dispersion and Multi-Path Propagation in Partial Discharges Location

2020

View full text Add to dashboard Cite

“…Due to the characteristics of the insulating medium that these elements present, the inherent losses of the pulses are very low, for example, in the case of a GIS in the presence of barriers and discontinuities the attenuation is 2 dB/m. However, when the insulation medium is solid, as in power cables, this behaves as a low pass filter and the UHF components of the pulses are significantly attenuated with the distance from the focus [ 36 ]. This characteristic is useful to be selective in the location of PD sources when UHF measurements are performed in cables and accessories; if PD pulses are detected in the UHF range the sensor is close to the origin of the defect.…”

Section: Pd Sensors and Frequency Converter For Pd Measurements Inmentioning

confidence: 99%

Application of HFCT and UHF Sensors in On-Line Partial Discharge Measurements for Insulation Diagnosis of High Voltage Equipment

Álvarez

Garnacho

Ortego

et al. 2015

Sensors

165

View full text Add to dashboard Cite

Partial discharge (PD) measurements provide valuable information for assessing the condition of high voltage (HV) insulation systems, contributing to their quality assurance. Different PD measuring techniques have been developed in the last years specially designed to perform on-line measurements. Non-conventional PD methods operating in high frequency bands are usually used when this type of tests are carried out. In PD measurements the signal acquisition, the subsequent signal processing and the capability to obtain an accurate diagnosis are conditioned by the selection of a suitable detection technique and by the implementation of effective signal processing tools. This paper proposes an optimized electromagnetic detection method based on the combined use of wideband PD sensors for measurements performed in the HF and UHF frequency ranges, together with the implementation of powerful processing tools. The effectiveness of the measuring techniques proposed is demonstrated through an example, where several PD sources are measured simultaneously in a HV installation consisting of a cable system connected by a plug-in terminal to a gas insulated substation (GIS) compartment.

show abstract

“…It causes temporal wave spreading at a given wavelength. Absorption of moisture or water ingress changes the dielectric and semiconductor properties of the cable thereby attenuation and dispersion properties of the cable [6]. The semi conducting layer between the conductor and dielectric to obtain uniform electrical field distribution increases the conductor impedance which in turn increases the attenuation constant [7].…”

Section: Signal Propagation In Cablesmentioning

confidence: 99%

Partial discharge location in power cables using a double ended method based on time triggering with GPS

Mohamed¹,

Siew²,

Soraghan³

et al. 2013

IEEE Trans. Dielect. Electr. Insul.

View full text Add to dashboard Cite

Partial discharge (PD) diagnostics is the most widely used tool to assess the insulation condition of insulated power cables which facilitates informed maintenance planning leading to extended service life of ageing assets. Time domain reflectometry (TDR) using a single ended or double ended approach is the most widely used method for locating PD sources. The success of the single ended method is dependent upon cable network design. However, by monitoring PDs at both ends of the cable, i.e. double-ended PD monitoring, higher accuracy of PD location can be achieved with a higher success rate. The double ended method is not widely used due to its complex system design, time synchronization and communication requirement between measurement units. This paper proposes a double ended PD location system which triggers on the predefined one pulse per second (1PPS) signal obtained from a global positioning systems (GPS) using novel time based triggering logic (TBTL) implemented in field programmable gate arrays (FPGA). This system ignores non-useable (not synchronized) data caused by flywheel 1PPS from GPS receiver due to any short-term loss of satellite signals which eventually reduces the PD location accuracy. Furthermore TBTL also ignores spurious triggering pulses radiated from noise sources within the substation. With the use of a communication link between two ends of the cable provided via mobile broadband together with TBTL, eliminated the acquisition of non-useable(not synchronized) data. Based on laboratory tests and on-site measurements PD location accuracy of less than ± 10 m can be achieved. The system design, laboratory tests and on-site measurements are discussed

show abstract

Dispersion and PD detection in shielded power cable [Feature article]

Cited by 27 publications

References 5 publications

Effects of Dispersion and Multi-Path Propagation in Partial Discharges Location

Effects of Dispersion and Multi-Path Propagation in Partial Discharges Location

Application of HFCT and UHF Sensors in On-Line Partial Discharge Measurements for Insulation Diagnosis of High Voltage Equipment

Partial discharge location in power cables using a double ended method based on time triggering with GPS

Contact Info

Product

Resources

About