Thermo-hydraulic analysis on long three-phase coaxial HTS power cable of several kilometers

The Société Nationale des Chemins de fer Français (SNCF) is facing a significant challenge to meet the growth in rail traffic while maintaining continuous service, particularly in densely populated areas such as Paris. To tackle this challenge, the SNCF has implemented several electrification projects. These projects aim to reduce line losses and decrease voltage drops on the railway network. Amongst the possible technological choices, high temperature superconductor (HTS) cables have been evaluated, since they offer greater energy density at lower electrical losses than conventional cables. This feature is advantageous in order to transmit more electrical energy at a lesser footprint than conventional cable, therefore avoiding costly modifications of the existing infrastructures. In the present work, the electromagnetic response of two HTS cables topologies, unipolar and bipolar, was analyzed, and their impact on a direct current (DC) railway network under load was assessed. A commercial finite element (FE) software, COMSOL Multiphysics, was used to carry out a detailed FE model that accounts for the non-linearity of the electrical resistivity ρ (J, B, θ) of the superconducting cable. This FE model was coupled with a lumped-parameter circuit model of the railway network, which is particularly suited for transient simulations considering train motion. Based on a case study representing a portion of the Parisian railway network, it was found that the insertion of a superconducting cable can result in a reduction of electrical losses by 60% compared to conventional cable as well as an 8.6% reduction in the total electrical consumption of the traction network.

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“…m of the liquid nitrogen circulating in the cable and the pressure drop ∆p between the inlet and the outlet [57] as follows:…”

Section: Design Of the Cooling Systemmentioning

confidence: 99%

Impact of Superconducting Cables on a DC Railway Network

et al. 2023

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“…Higher operating pressure in the cooling system can prevent bubble generation by increasing the boiling temperature of liquid nitrogen. But the operating pressure should not exceed the allowable pressure of the cryostat [18], [19]. Figure 5 shows an example of operating limiting condition for the HTS power cable cooling system.…”

Section: Hts Power Cable Operating Limit Conditionmentioning

confidence: 99%

Pressure Drop Characteristics of Concentric Spiral Corrugation Cryostats for a HTS Power Cable Considering Core Surface Roughness

Choi

Kim

2023

Preprint

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Recently, interest in renewable energy systems such as solar, hydrogen and wind power has increased as an alternative to fossil fuels. Renewable energy sources such as large wind and solar farms require long-distance power transmission because they are located inland or offshore, far from the city where power is required. High Temperature Superconducting (HTS) power cables have more than 5 times the transmission capacity and less than one-tenth the transmission loss compared to the existing cables of the same size, enabling large-capacity transmission at low voltage. In addition, it has perfect magnetic shielding performance, so it can fundamentally solve the electromagnetic wave environmental problem, and does not use any environmental pollutants in the existing high-voltage power cables. For commercialization of HTS power cables, unmanned operation and long-distance cooling technology of several kilometers is essential, and pressure drop characteristic is important. The cryostat's spiral corrugation tube is easier to bend, but unlike the round tube, the pressure drop cannot be calculated using the Moody chart. In addition, it is more difficult to predict the pressure drop characteristics due to the irregular surface roughness of the binder wound around the cable core. In this paper, a suitable CFD model of a spiral corrugation tube with a core was designed by referring to the water experiments from previous studies. In the four cases geometry, when the surface roughness of the core was 10mm, most errors were 15% and the maximum errors were 23%. These results will be used as a reference for the design of long-distance HTS power cables.

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“…where V c and V s are the voltage drop of the phase conductor and the shield layers, respectively; I c and I s are the currents of the conducting and shield layers, respectively; L i and R c are the self-inductance and resistance of the conducting layers, respectively; and M ij is the mutual inductance of the HTS cable. The self and the mutual inductance of the HTS cable were dependent on the pitch length and radius of each layer, given by Equations (6) and 7.…”

Section: Hts Layer Hts Layermentioning

confidence: 99%

“…Various configuration of HTS power cables have been reported, such as single-core cable, triaxial cable, and coaxial cable [4]. Among these configurations, coaxial HTS cables have been studied widely recently, since this configuration can reduce AC loss by designing proper parameters such as radius, direction, and twisting pitch [6,7]. Multiple layers of HTS tapes are used to enhance cable capacity.…”

Section: Introductionmentioning

confidence: 99%

A Simplified Model of Coaxial, Multilayer High-Temperature Superconducting Power Cables with Cu Formers for Transient Studies

Nguyen

Lee

et al. 2019

Energies

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Bypassing transient current through copper (Cu) stabilizer layers reduces heat generation and temperature rise of high-temperature superconducting (HTS) conductors, which could protect HTS cables from burning out during transient conditions. The Cu layer connected in parallel with HTS tape layers impacts current distribution among layers and variations of phase resistance in either steady-state or transient conditions. Modeling the multilayer HTS power cable is important for transient studies. However, existing models of HTS power cables have only proposed HTS cables without the use of a Cu-former layer. To overcome this problem, the authors proposed a multilayer HTS power cable model that used a Cu-former layer in each phase for transient study. It was observed that resistance of the HTS conductor increased significantly in the transient state due to a quenching phenomenon, which made the transient current mainly flow into the Cu-former layers. Since resistance of the Cu-former layer has a significant impact on the transient current, detailed modeling of the Cu-former layer is described in this study. The feasibility of the developed HTS cable model is evaluated in the PSCAD/EMTDC program.

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Thermo-hydraulic analysis on long three-phase coaxial HTS power cable of several kilometers

Cited by 7 publications

References 23 publications

Impact of Superconducting Cables on a DC Railway Network

Impact of Superconducting Cables on a DC Railway Network

Pressure Drop Characteristics of Concentric Spiral Corrugation Cryostats for a HTS Power Cable Considering Core Surface Roughness

A Simplified Model of Coaxial, Multilayer High-Temperature Superconducting Power Cables with Cu Formers for Transient Studies

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