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

Abstract

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.

Fault Analysis and Design of a Protection System for a Mesh Power System with a Co-Axial HTS Power Cable

“…The co-axial HTS cable using Cu-formers is used to conduct powers. Since this study is a continuation of the research presented in [21], the simplified HTS cable model for the transient analysis in previous work is adopted in this study for fault analysis and design of the protection system. Figure 2 shows the operation characteristic and the equivalent scheme of the co-axial HTS cable.…”

“…A custom model with a transformer section is used to represent the self and mutual inductances of the HTS cable. More explanation of the co-axial HTS cable could be found in [21]. Detailed parameters of the tested system are given in Table 1.…”

“…Operation characteristic and equivalent scheme of co-axial HTS cable adopted from[21]: (a) current flow into each phase in the normal state; (b) current flow into each phase in the transient state; (c) equivalent circuit of the HTS power cable.…”

Impacts of a LVRT Control Strategy of Offshore Wind Farms on the HTS Power Cable

“…Substituting the control inputs from (26) and (27) in (24) and (25), we have Figure 4b shows a block representation of the MSC controller based on (28) and (29), which includes the current control and maximum power point tracking (MPPT) control loops. In the current control loop, the current reference i * sd is set equal to zero and i * sq is given by (30).…”

“…A detailed converter controller of PMSG-based WTG is presented. The simplified coaxial HTS cable model for transient studies adopted from [26] is used to evaluate the impact of LVRT strategies.…”