Development of 500-kV XLPE cables and accessories for long distance underground transmission line. III. Electrical properties of 500-kV cables

Joints for 500-kV XLPE cable are now under development inJapan to enable the long-distance transmission of high-capacity power to urban areas. Basic research was carried out from 1989 to 1992 that determined joint type and design values. This paper reports on the electric performance of the fabricated joints.Various tests were conducted to evaluate the performance and the design values. As a results of this evaluation it was found that it was possible to realize joints for 500-kV XLPE cable.Field tests will be conducted as the final stage to confirm the long-term performance of the system.

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“…confirms that the design lifetime can be achieved. These test results are reported in subsequent paper [7].…”

Section: -3 Thickness Dependence Of Breakdown Stresssupporting

confidence: 62%

“…These coefficients or thickness dependence were detenn ined based on breakdown test data for XLPE cables [7]. But as shown above, the performance-governing factors for EMJs are, as for XLPE cables, the contaminants and the protrusions.…”

Section: A Reinforcing Insulationmentioning

confidence: 99%

Development of 500-kV XLPE cables and accessories for long-distance underground transmission lines. IV. Electrical properties of 500-kV extrusion molded joints

Takeda

Izumi²,

Asari

et al. 1996

IEEE Trans. Power Delivery

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“…The values of the AC inception stress for electrical treeing versus defect tip radius of curvature in XLPE insulation have been reported in References [8,[14][15][16]. Figure 1 shows the experimental data of several researches for the Laplacian field at the defect tip calculated without considering the space charge effects as a function of the defect tip radius of curvature.…”

Section: Effect Of Tip Radius On Inception Stressmentioning

confidence: 98%

Factors influencing electrical treeing in XLPE insulation

Malik

Al‐Abdullah

Al-Arainy

et al. 2006

Euro. Trans. Electr. Power

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SUMMARYThis paper reviews the factors that influence the electrical stress required for initiation of electrical trees in crosslinked polyethylene (XLPE) insulation. Mathematical model relating the average tree inception stress with the defect tip radius of curvature has been provided for AC and impulse voltages. The resulting equation for AC treeing inception stress is verified by experimental measurements. Moreover, the effects of voltage magnitude, defect tip radius, and time of voltage application on partial discharge (PD) properties are studied, and the conditions for the initiation of bush-and branch-type trees are identified. For each type of tree, the variation of PD level with tree length is investigated experimentally. The results show that a minimum stress is required below which treeing cannot initiate in XLPE insulation. Moreover, during the early phase of tree propagation, tree length follows a self-limiting growth model and in this phase, tree length and the maximum PD levels are correlated.

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“…In two recent publications [1,2], a graph ( Figure 1) based on limited measured data was presented for the ILaplacian field in XLPE required for tree initiation vs defect tip radius. No indication was provided for the geometry in which the experiments were carried out; however, the tip radii employed suggest the use of Ogura needles in a needle-to-plane geometry.…”

Section: N T~~~u C T I~nmentioning

confidence: 99%