Effect of voltage reversal on space charge and transient field in LDPE films under temperature gradient

Chen, X.; Wang, X.; Wu, Kai; Peng, Zongren; Cheng, Yanhai; Tu, Demin

doi:10.1109/tdei.2012.6148512

Cited by 59 publications

(26 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(18) and (19) show, the attenuation and dispersion coefficients of the pressure wave in an inhomogeneous medium have many high-order terms, compared with those in a uniform medium. The series of high-order terms will aggravate the attenuation and dispersion of the pressure wave.…”

Section: Recovery Of Temperature Gradient Effectmentioning

confidence: 99%

“…(15) This affects the injection and migration of charge, leading to a gradient of conductivity and then a gradient of electric field. (17,18) The localized field enhancement in a polymeric cable due to space charge accumulation is unpredictable, posing a vital threat to the cable insulation in service, especially under applied dc voltage reversal or outage. In recent years, a few studies on the space charge dynamics in a cross-linked polyethylene (XLPE) cable under temperature gradient and dc voltage have been published.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Recovery Algorithm for Space Charge Waveform in Coaxial Cable under Temperature Gradient

2017

Sensors and Materials

View full text Add to dashboard Cite

The accumulation of space charge in a coaxial cable under high-voltage direct current (HVDC) may lead to the serious distortion of the internal electrical field, and thus extremely affect the long-term reliability of the cable in service. Therefore, it is significant to measure the space charge characteristic in a full-size power cable in real time. However, because of the existence of a temperature gradient across the cable insulation under DC electrical stress, the density of the dielectric will be inhomogeneous. Moreover, the effect of the coaxial structure on the distortion of measuring waveforms has to be taken into consideration. In this paper, an improved pulsed electroacoustic (PEA) system suited for a full-size power cable under a temperature gradient was realized by designing the units of pulse injection and signal detection. Then, the charge density was corrected according to the nonuniform electric stress distribution and the divergent acoustic propagation. Finally, the system transfer function was amended by adding the dispersion coefficient's quadratic approximation to the general solution of the general wave propagation equation. With this new recovery algorithm, the distortion of the waveform caused by the cable's coaxial structure, acoustic waves' attenuation and dispersion, and temperature gradient effect can be recovered successfully.

show abstract

Section: Recovery Of Temperature Gradient Effectmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Recovery Algorithm for Space Charge Waveform in Coaxial Cable under Temperature Gradient

2017

Sensors and Materials

View full text Add to dashboard Cite

show abstract

“…The upper electrode was made of SC (semiconductor: carbon-loaded polyethylene) and the measurement electrode is made of Aluminum. Owing to the effect of a temperature gradient on the space charge waveform in the PEA method, the space charge waveforms under temperature gradient were recovered according to the acoustic wave recovery method, described in [18,19]. It had previously been noted that the changes in the space charge distribution between 20 minutes and 2 hours were small so that it seems as though much of the space charge dynamics were contained in the first 20 minutes.…”

Section: Experimental Details and Sample Preparationmentioning

confidence: 99%

“…In the case of the velocity, the higher the temperature, the lower the velocity, so the temperature gradient will extend the signal and then lower the amplitude. In order to remove this effect a correction, taking the velocity into account, has been employed [18,19]. However, the temperature can also affect the attenuation of the sound wave, the higher the temperature, the greater the attenuation.…”

Section: Single Layer Samplesmentioning

confidence: 99%

Study of the factors that suppress space charge accumulation in LDPE nanocomposites

Wang

et al. 2014

IEEE Trans. Dielect. Electr. Insul.

View full text Add to dashboard Cite

Two mechanisms have been proposed to explain the suppression of space charge in polyethylene by the addition of nano-fillers, i.e. an interface change that reduces charge injection and a bulk modification that affects charge migration and recombination. The relative importance of each mechanism in Low Density Polyethylene (LDPE) nanocomposites is investigated by the measurement of space charge in samples of doublelayer and triple-layer structures. The experimental results show that the nano-fillers reduce charge injection, but do not entirely eliminate the space charge. Bulk changes also play an important role in space charge suppression. The space charge near the interface between the unfilled LDPE and nanocomposites shows a surface charge at 20 C, but at 60 C a bipolar blocking phenomenon is observed in some circumstances. It is shown that these space charge distributions can be reproduced using a band theory approach with the assumption that the introduction of deep traps by nano-fillers raises the Fermi level of the nanocomposite towards the conduction level.

show abstract

“…1 shows our former work, (a1) and (a3) are taken from Ref. [12], (b1) and (b3) are taken from Ref. [13], (a2) and (b2) are newly measured.…”

Section: A Space Charge Distribution Of Single Layer Samplesmentioning

confidence: 99%

Study on suppression mechanism of space charge accumulation in nano-doped LDPE

Wang

et al. 2012

2012 Annual Report Conference on Electrical Insulation and Dielectric Phenomena

View full text Add to dashboard Cite

The introduction of nano-fillers into polyethylene can suppress space charge accumulation. The mechanism of this phenomenon hasn't been understood clearly, and has been explained in two different ways, i.e. an interface behavior that reduces charge injection and a bulk property that affects charge migration. In order to investigate which factor determines the space charge behavior in LDPE nano-composites, samples of triple-layer structure are measured. The experimental results show that the nano-fillers can reduce charge injection. However, the reduced charge injection cannot entirely remove the space charge. The bulk property also plays an important role in space charge suppression. Furthermore, a bipolar blocking phenomenon is found in our triple layer sample at high temperature. This can be explained by a shift in the apparent Fermi (charge demarcation) level near the electrode due to the trapping of injected charge, which increases the interface barrier.

show abstract

Effect of voltage reversal on space charge and transient field in LDPE films under temperature gradient

Cited by 59 publications

References 19 publications

Recovery Algorithm for Space Charge Waveform in Coaxial Cable under Temperature Gradient

Recovery Algorithm for Space Charge Waveform in Coaxial Cable under Temperature Gradient

Study of the factors that suppress space charge accumulation in LDPE nanocomposites

Study on suppression mechanism of space charge accumulation in nano-doped LDPE

Contact Info

Product

Resources

About