The application of superconducting fault current limiters (SCFCLs) in power systems is very attractive because SCFCLs offer superior technical performance in comparison to conventional devices to limit fault currents. Negligible impedance at normal conditions, fast and effective current limitation within the first current rise and repetitive operation with fast and automatic recovery are the main attributes for SCFCLs. In recent years there has been a significant progress in the research and development (R&D) of SCFCLs. This paper gives an extended review of different SCFCL concepts, SCFCL applications and the R&D status. Within the first part of this paper the most important SCFCLS and, to a limited extent, non-superconducting fault current limiter (FCL) concepts are explained and compared. The second part reviews interesting SCFCL applications at the distribution and transmission voltage level and the third part shows in detail the R&D status. It can be summarized that SCFCLs are, at present, not commercially available but several successful field tests demonstrated the technical feasibility of SCFCLs. First distribution level applications are expected soon. Considerable economical and technical benefits can be achieved by applying SCFCLs at the distribution and transmission voltage level.

https://iopscience.iop.org/article/10.1088/0953-2048/20/3/R01/pdf

High-temperature superconductor fault current limiters: concepts, applications, and development status

Superconducting fault current limiters for electric power systems have been researched. A magnetic shielding type superconducting fault current limiter is developed in the authors' research on superconducting fault current limiters. This limiter consists of a copper primary winding, a superconducting cylinder, an iron core and a control coil. The superconducting cylinder has a Bi2212 thick film on a MgO substrate. The control coil consists of some metallic rings, and the fault level can be adjusted by changing the number of the rings. To design a prototype limiter, the AC magnetic shielding and loss characteristics of small models were measured. The prototype limiter is 6600 V in rated voltage and 400 A in rated current. The superconducting cylinder is 0.45 m in diameter and about 1 m in height. Only the superconducting cylinder was designed to be cooled by liquid nitrogen. The experimentally manufactured limiter is about 1.3 m in width, about 0.6 m in depth and about 2 m in height.

Performance of a high-Tc superconducting fault current limiter-design of a 6.6 kV magnetic shielding type superconducting fault current limiter

Design, parameters, and application areas of a superconducting fault current limiter (FCL) are analyzed on the basis of the requirements of power systems. The comparison of resistive and inductive designs is carried out. An example of the effective application of FCLs in distribution substations is considered and the gain from the FCL installation is discussed. It is shown that an FCL not only limits a fault current but also increases the dynamic stability of the synchronous operation of electric machines. The calculation procedure of the parameters of an inductive FCL for a specific application case is described.

Superconducting FCL: design and application

The present paper proposes a new the fault current limiter (FCL), which consists of a high T/sub c/ superconducting (HTS) element, three coils wound on the same core, and a magnetic field coil covering the HTS element. In this FCL, the initial limiting current level can be controlled by adjusting the inductances of the coils. Furthermore, an external AC magnetic field is applied to the HTS element to get higher resistance in the current-limiting phase. A current-limiting experiment by a model FCL was carried out, and the limiting performance of the FCL was observed. Both the initial limiting current level and the limiting impedance could be increased in this FCL compared with the corresponding values of the HTS element itself.

Development of flux-lock-type fault current limiter with high-T/sub c/ superconducting element

A survey on fault current limiters: Development and technical aspects

The application of a superconductor to a fault current limiter in a power system has been researched. The authors developed a magnetic shielding type superconducting fault current limiter using a Bi2212 thick film cylinder. This limiter consists of a primary winding on a superconducting cylinder for generating an AC magnetic field, the cylinder for shielding the field, an iron core for magnetic members and a control ring for controlling fault currents. When a fault occurs, the superconductive cylinder quenches and a magnetic circuit is formed inside the cylinder. As a result, the limiter has a high impedance to limit the fault current. The present study shows the limiting and recovery characteristics of the fault current limiter. >

M. Okazaki

Papers

A magnetic shielding type superconducting fault current limiter using a Bi2212 thick film cylinder