Cables proximity effects

A 16.6 Skin and proximity effects in a multicore cable 16/547 A 16.7 Short-time rating of cables 16/547 A 16.8 Termination of cables 16/548... 

However, there may not be an appreciable improvement in the proximity effect between each section, unless the transpositions are increased infinitely, as in the case of a stranded three-phase cable which has continuously twisted conductors and represents an ideal transposition. In addition, there is no change in the skin effect. This arrangement therefore has the purpose primarily of achieving an inductively balanced system and hence a balanced sharing of load and equal phase voltages at the far end. 

Ghien, G. H. and R. W. G. Bucknall. 2009. Harmonic calculation of proximity effect on impedance characteristics in subsea power transmission cables. IEEE Trans. Power Deliv. 24(2) 2150-2158. 

Ametani, A. et al. 2013. Wave propagation characteristics on a pipe-type cable in particular reference to the proximity effect. lEE Journal of High Voltage Engineering Conference, Kyoto, Japan. Paper HV-13-005. 

The influence of skin effects in a multi-core cable is almost the same as that of a multiphase busbar system, discussed in Sections 28.7 and 28.8. However, unlike a busbar system, the resistance and inductive reactance for various sizes of cables can be easily measured and are provided by leading manufacturers as standard practice in their technical data sheets. To this extent, making an assessment of skin effects in cables is easy compared to a busbar system. Since all the phases in a cable, of a 3-core or 3 72-core are in a regularly twisted formation throughout the length of the cable, they represent the case of an ideal phase transposition (Section 28.8.4(3)) and almost nullify the effect of proximity. 

Nanocarbon hybrids have recently been introduced as a new class of multifunctional composite materials [18]. In these hybrids, the nanocarbon is coated by a polymer or by the inorganic material in the form of a thin amorphous, polycrystalline or single-crystalline film. The close proximity and similar size domain/volume fraction of the two phases within a nanocarbon hybrid introduce the interface as a powerful new parameter. Interfacial processes such as charge and energy transfer create synergistic effects that improve the properties of the individual components and even create new properties [19]. We recently developed a simple dry wrapping method to fabricate a special class of nanocarbon hybrid, W03 /carbon nanotube (CNT) coaxial cable structure (Fig. 17.2), in which W03 layers act as an electrochromic component while aligned... 

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