Research of temperature destruction effect on cables insulation operation life

Pugach, V. N.; Polyakov, D. A.; Nikitin, K. I.; Tereshchenko, N. A.; Komarov, I. V.

doi:10.25206/1813-8225-2019-168-70-74

Cited by 1 publication

(6 citation statements)

References 11 publications

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“…Within the framework of the applied problem we are solving, only one destabilizing factor is considered, due to the pulse current i p (t) flowing through the electric wires and cables with various ATPs. At certain (threshold) values I mpk of the amplitude I mp of current pulses i p (t) of one or another temporal shape flowing through the current-carrying parts (inner core and outer shell) of the CWP, due to the intense Joule heating of these metal parts of the wires (cables), processes of thermal destruction in their belt insulation can occur [1,6,7]. It should be noted that at values of the amplitudes I mp of pulse currents i p (t) of hundreds of kiloamperes, destructive processes in the polymer insulation of the studied CWP can also arise from the action of large electrodynamic forces on cables (wires) [2].…”

Section: State-of-the-art and Urgency Of The Problemmentioning

confidence: 99%

“…where δ=Δ p /T p is the current damping coefficient; ω=2π/T p is the circular frequency of current oscillations; T p is the period of current oscillations; Δ p =ln(I mp1 /I mp3 ) is the logarithmic decrement of pulse current i p (t) oscillations with the first I mp1 and the third I mp3 amplitudes in electrical circuits; k p2 =[exp(-Δ p /2π•arcctgΔ p /2π)sin(arcctgΔ p /2π)] -1 is the normalizing factor for the damped sinusoidal current i p (t) flowing in the wire (cable). For the temporal shape (7) of the change in the wire (cable) of the current pulse i p (t) at t p =3T p in (2), the calculation expression for the action integral J CiA of the current pulse i p (t) flowing in the investigated low-and high-current circuits of modern electrical engineering takes the following approximate analytical form:…”

Section: State-of-the-art and Urgency Of The Problemmentioning

confidence: 99%

“…With regard to the applied problem being solved, the threshold values I mpk of the amplitude I mp of the current pulse i p (t) of the given temporal shape will correspond to the permissible short-term heating temperature θ CiS = θ lS with this pulse current i p (t) of the electric wire and cable with the selected insulation. Therefore, from (2), taking into account (6), (8) and the data of Table 2, when the relation S Ci = S Cil is fulfilled, the calculated threshold values I mpk of the amplitudes I mp and I mp1 of the axial current pulses i p (t) for the time shapes indicated according to (5), (7) flowing along the investigated insulated wires and cables in low-and high-current circuits of electrical engineering and electronics can also be determined in the considered approximation.…”

Section: State-of-the-art and Urgency Of The Problemmentioning

confidence: 99%

“…. (10) Similarly to (9), using (10) to find the calculated value I mpk for a particular wire (cable) with known characteristics S Ci and C l (see Table 2) at given temporal parameters Δ p и T p for the discharge pulse current i p (t) flowing through the CWP will actually be reduced to the calculation according to (7) of the numerical value of the normalizing coefficient k p2 ≥1.…”

Section: State-of-the-art and Urgency Of The Problemmentioning

confidence: 99%

“…Note that the calculated relations ( 9), ( 10) for determining the threshold values I mpk of the amplitudes I mp of the axial current pulses i p (t), varying in time t according to ( 5), (7) according to the aperiodic dependence and the law of the exponentially decaying sinusoid, cover a wide nomenclature of temporary shapes and ATPs of used in electrophysical practice single current pulses i p (t) flowing through current-carrying parts of wires and cables with PVC, R and PET belt insulation in modern pulsed power engineering, electrical engineering and electronics.…”

Section: State-of-the-art and Urgency Of The Problemmentioning

confidence: 99%

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Destruction of polymer insulation and threshold amplitudes of current pulses of different temporal shapes for electric wires and cables in the low- and high-current circuits of pulse power engineering, electrical engineering and electronic devices

Баранов¹,

Buriakovskyi²,

Князєв³

2021

Electrical Engineering & Electromechanics

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Goal. Development of engineering method for settlement of threshold amplitudes Impk of single-pulse current ip(t) of different temporal shapes for electric wires and cables with polyethylene (PET), polyvinylchloride (PVC) and rubber (R) half-length insulation, used in modern pulsed power engineering, electrical engineering and electronics in their low- and high-current circuits. Methodology. Basis of the theoretical and applied electrical engineering, electrical power engineering, electrophysics bases of technique of high-voltage and large pulsed currents, bases of low- and high-current electronics, measuring technique, electromagnetic compatibility and standardization. Results. Development of engineering method is executed on close calculation determination of threshold amplitudes Impk of single-pulse axial-flow current ip(t) of different temporal shapes for electric wires and cables with copper (aluminum) current-carrying parts and PET, PVC and R half-length insulation, used in the ow- and high-current circuits of pulsed electrical power engineering, electrical engineering and electronics. Electrothermal resistibility of half-length insulation of the examined cable and wire products (CWP), proper maximum to the possible temperatures of heating of current-carrying and insulating parts of the probed wires and cables and shutting out the offensive of the phenomenon destruction in the indicated insulation of CWP, was fixed based on this method. Calculation analytical correlations are obtained for finding in probed CWP of threshold numeral values of Impk amplitudes of pulses of current ip(t), time-varying both on aperiodic dependence of type τf/τp with duration of their front τf and duration of their pulses τp and by law of exponential attenuation sinewave. It is shown that at Imp>Impk destruction of their half-length insulation, resulting in the decline of service life of CWP, will come from the thermal overheat of current-carrying parts of the examined electric wires and cables. The examples of practical application of the offered method are resulted upon settlement for a radiofrequency coaxial cable RC 50-4-11 with middle sizes is easily soiled with continuous PET insulation of threshold amplitudes of Impk of standard aperiodic pulses of current ip(t) from nano-, micro- and millisecond temporal ranges of shape of τf/τp=5 ns/200 ns, τf/τp=10 μs/350 μs and τf/τp=7 ms/160 ms. It is shown that with the proper growth of parameter τp>>τf for flow on a continuous copper tendon and split copper shell of radiofrequency coaxial cable RC 50-4-11 with middle sizes is easily soiled indicated homopolar pulses of current ip(t) substantial diminishing of their threshold amplitudes of Impk (with 531,2 кА for the nanosecond pulse of current of type 5 ns/200 ns to 1.84 кА for the millisecond impulse of current of type of 7 ms/160 ms takes place). Originality. An engineering method is first developed for close settlement of threshold numeral values of Impk amplitudes of single-pulse axial-flow current ip(t) of arbitrary peak-temporal parameters for electric wires and cables with copper (aluminum) current-carrying parts and PET, PVC and R half-length insulation. Practical value. Application in electrical engineering practice of the offered engineering method for determination of threshold amplitudes Impk of the indicated pulses of axial-flow current ip(t) for the probed electric wires and cables will allow considerably to increase service life of examined CWP.

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Section: State-of-the-art and Urgency Of The Problemmentioning

confidence: 99%

Section: State-of-the-art and Urgency Of The Problemmentioning

confidence: 99%