AC loss modelling and experiment of two types of low-inductance solenoidal coils

Abstract

Low-inductance solenoidal coils, which usually refer to the nonintersecting type and the braid type, have already been employed to build superconducting fault current limiters because of their fast recovery and low inductance characteristics. However, despite their usage there is still no systematical simulation work concerning the AC loss characteristics of the coils built with 2G high temperature superconducting tapes perhaps because of their complicated structure. In this paper, a new method is proposed to simulate both types of coils with 2D axisymmetric models solved by H formulation. Following the simulation work, AC losses of both types of low inductance solenoidal coils are compared numerically and experimentally, which verify that the model works well in simulating non-inductive coils. Finally, simulation works show that pitch has significant impact to AC loss of both types of coils and the inter-layer separation has different impact to the AC loss of braid type of coil in case of different applied currents. The model provides an effective tool for the design optimisation of SFCLs built with non-inductive solenoidal coils.

A Novel Helical Superconducting Fault Current Limiter for Electric Propulsion Aircraft

“…Resistive SFCLs need to be configured as bifilar type to achieve non-inductive or low inductive structures. This is beneficial for power systems to avoid poor voltage regulation and degraded power quality [13]- [15]. In addition to low inductance, SFCL also require low AC loss in normal operation, effective fault current limiting performance, especially at the peak of the first half cycle of a fault, and fast recovery time after the fault been cleared [12]- [15].…”

“…A 12 kV/28 MVA resistive SFCL was developed using YBCO tape in a multifilar pancake configuration in the project "Ampacity" in 2014 [19]. Among these, the helical bifilar coil is favorable for the high voltage applications due to the fact that the voltage gradient between turns near the terminals are relatively lower than the bifilar pancake and straight-line types [13], [23]. In addition, a helical bifilar coil exhibits better heat transfer performance compared with a concentrated pancake type coil when sudden excessive energy is dissipated in the coil during a fault.…”

Review of the AC loss computation for HTS using H formulation

“…Liang et al studied the AC losses in two types of lowinductance solenoidal HTS coils using 2D axisymmetric H-formulation and experiment method [37]. Shen et al used the 2D axisymmetric H-formulation to investigate the power dissipation a circular shape HTS coils under the action of different oscillating fields and currents [38].…”

Overview of H-Formulation: A Versatile Tool for Modeling Electromagnetics in High-Temperature Superconductor Applications

“…In [41], a full 3D model of a racetrack HTS coil was built with the homogenization approach and compared to 2D models. Two-dimensional axisymmetric H-formulation FEM models were also developed [42]- [44].…”