An open-source 2D finite difference based transient electro-thermal simulation model for three-phase concentric superconducting power cables

The use of High Temperature Superconducting (HTS) cables in power systems increases transmission capacity whereas reducing the volume of the installation. In addition, when transmission currents exceed a few kA, HTS DC cables significantly reduce power losses, right-of-ways and total system mass. This summary describes the various studies to be carried out in order to correctly dimension DC HTS cables for the new railway network envisaged by the French company SNCF, which has to take into account the ultra-urban needs. The process used to design DC cables for different operating current values between 5 kA and 20 kA at 1 750 V using commercial (RE)BaCuO tapes is presented. In this design stage, the dependence of the critical current density Jc(B, θ, T) of the superconducting tapes, the thermal properties of the materials used, and the different cooling modes as a function of the cable length are taken into account. Finally, we discuss a cryogenic solution to protect the cable in case of short-circuit or overload.

Section: Hts Cable Designmentioning

confidence: 99%

Design and modelling tools for DC HTS cables for the future railway network in France

Hajiri

Berger

Lévêque

et al. 2022

“…Further, cable characteristics under fault conditions can be analyzed using various methods, such as the finite difference method (FDM), equivalent circuit method (ECM), and finite element method (FEM). The FDM, which is often in the form of self-produced codes, can be used to investigate the thermohydraulic behavior of HTS cables [12]. The ECM, on the other hand, has been applied to analyze the transient characteristics of a co-axial HTS cable under various fault conditions [13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Transient research on distribution networks incorporating superconducting cables utilizing field–circuit coupling method

Li,

Tang,

Ren

et al. 2023

High temperature superconducting (HTS) cable represents a promising solution for fulfilling the power demands of cities with large loads and high density. However, due to their connection to the distribution network, HTS cables are vulnerable to fault currents exceeding ten times their rated current, which poses a serious threat to both the safety of the cable and the operation of the grid. Considering the highly nonlinear nature of superconducting conductivity, this study develops a field–circuit coupling model to investigate the transient characteristics of distribution networks incorporating superconducting cables (DNSC). Firstly, a finite element model based on the two-dimensional H formulation was built to calculate the electrical and thermal parameters of the HTS cable. Subsequently, an equivalent circuit model of the distribution network was employed to estimate the short-circuit currents. Communicating via a co-simulation server, the superconducting cable current and distribution network impedance were updated in each step. Further, based on an actual DNSC system in Shenzhen, China, the highest quenching temperature of the cable and the maximum fault current of busbars were assessed. Finally, by integrating current limiters into the system, the withstand capability of the cable and busbars was determined, which indicates that the improved protection configuration can effectively suppress fault currents and ensure safe operation. Successfully applied to an actual distribution network, the co-simulation model utilizing the field–circuit coupling method addresses the challenges of solving highly nonlinear and time-varying systems, enabling transient analysis and protection research for the integration of superconducting devices into the conventional grid.

“…This method has the advantages of possessing better numerical stability than the explicit method, and relying on fast solvers of the tridiagonal system thus requiring lower computational efforts in comparison with the implicit methods [48]. The ADI method has been successfully utilized for simulations of superconducting fault current limiters [49,50] and power cables [51] in recent years.…”

Section: Introductionmentioning

confidence: 99%

Quench analysis of a no-insulation REBCO magnet based on the ADI method considering the coupling effect of the cryostat

Zheng,

Liu,

Song

et al. 2023

A no-insulation (NI) REBCO superconducting magnet is under development at Wuhan National High Magnetic Field Center, China. The magnet with the liquid helium cryostat system has a compact structure to reduce the space required for operation. During a quench, the fast-changing spatial magnetic field around the NI magnet may induce a strong eddy current in the conductive parts of the cryostat. The eddy current and its associated Lorentz force will generate mechanical stress on the cryostat, especially on the thermal shield (TS). The mechanical strength of the cryostat needs verification in the preliminary design. Furthermore, the degree to which the electromagnetic coupling between the cryostat and NI magnet might impact the quench behaviors of the NI magnet remains uncertain. In this paper, a multi-physics quench model is newly developed for the NI REBCO magnet, and the alternating direction implicit method is employed for the solver of the thermal model to improve computational efficiency. This simulation model can consider the electromagnetic coupling effect between the NI magnet and cryostat by constructing a partial element equivalent circuit. A quench analysis has been performed and we found that: (1) The cryostat can function as a secondary shorted circuit to the NI magnet and slow down the quench speed to a certain extent. (2) During the rather fast inductive quench phase, the cryostat will experience an attraction force towards the quench propagation frontier. (3) A quench propagation from one end of the magnet can cause a significant z-axis unbalanced force on the TS. (4) Cryostat materials with drastically changed electrical conductivity can significantly affect their mechanical responses during a quench. However, the eddy current density and maximum Von Mises stress on the TS are barely affected by the thickness of the TS and the contact resistance of the NI REBCO magnet.