Three-dimensional Problems of the Theory of Elasticity. By A. I. Lur’e.1964. (Interscience Publishers)

Power systems are becoming more and more complex in nature due to the integration of several power electronic devices. Protection of such systems and augmentation of reliability as well as stability highly depend on limiting the fault currents. Several fault current limiters (FCLs) have been applied in power systems as they provide rapid and efficient fault current limitation. This paper presents a comprehensive literature review of the application of different types of FCLs in power systems. Applications of superconducting and non-superconducting FCLs are categorized as: (1) application in generation, transmission and distribution networks; (2) application in alternating current (AC)/direct current (DC) systems; (3) application in renewable energy resources integration; (4) application in distributed generation (DG); and (5) application for reliability, stability and fault ride through capability enhancement. Modeling, impact and control strategies of several FCLs in power systems are presented with practical implementation cases in different countries. Recommendations are provided to improve the performance of the FCLs in power systems with modification of its structures, optimal placement and proper control design. This review paper will be a good foundation for researchers working in power system stability issues and for industry to implement the ongoing research advancement in real systems.

https://www.mdpi.com/1996-1073/11/5/1025/pdf

Fault Current Limiters in Power Systems: A Comprehensive Review

A transformer is expected to be an useful component of resistive type superconducting fault current limiter (SFCL) using high-T/sub C/ superconducting (HTSC) element with constant critical current for easier adjustment of both the limiting impedance and the initial limiting current level. Therefore, the analysis for the fault current limiting characteristics of the resistive type SFCL using a transformer considering the resistance variance of HTSC element is needed because the resistance of HTSC element during a fault period is affected by the design condition of the transformer. In this paper, we investigated the limiting impedance and the initial limiting current level of the resistive type SFCL using a transformer as a function of the turn numbers' ratio between the primary winding and the secondary winding. The limiting impedance of SFCL was extracted by applying discrete Fourier transform (DFT) equation for the measured voltage and current data of SFCL. It was confirmed from the analysis that the transformer design with the lower turn numbers' ratio of the primary winding for the secondary winding was advantageous for the larger load current capacity of SFCL and that the transformer with the higher ratio design condition, on the other hand, was favorable for the larger fault current limiting capacity of SFCL.

Fault current limiting Characteristics of resistive type SFCL using a transformer

In this paper, we investigated the operational characteristics of the flux-lock type superconducting fault current limiter (SFCL) with series connection of two coils, which was suggested by us previously. This SFCL has the similar fault current limiting characteristics to the flux-lock type SFCL with parallel connection of two coils. The current limiting operation of the SFCL is performed by the generation of the magnetic flux between two coils when a fault happens and the fault current limiting characteristics of the SFCL are dependent on the inductance ratio and the winding direction of two coils. To confirm it, the operational characteristics of this SFCL were analysed based on its electrical equivalent circuit and the fault current limiting characteristics of this SFCL were investigated through the fault current limiting experiments. Through the analysis, it was shown that the limited fault current and the resistance of high-TC superconducting (HTSC) element could be adjusted by two coils' inductance ratio and the winding direction of two coils.

Operational Characteristics of Flux-Lock Type SFCL With Series Connection of Two Coils

This study aims to provide a comprehensive review of various superconducting fault current limiters (SFCLs) configurations. Regarding the applied technology, the different types of SFCLs are classified into three groups including quench-type SFCL, non-quench-type SFCL, and composite-type SFCL. Resistive-type SFCL, hybrid-type SFCL, magnetic-shielded iron-core-type SFCL, superconducting fault current limiting transformer, transformer-type SFCL, flux-lock-type SFCL, saturated iron-core-type SFCL, and resonance-type SFCL are some of the investigated structures. The structures are fully surveyed in terms of operating principle, technical feasibility, and recent advancements. The study is performed based on published information in papers, reports, and other available online documents. It is expected that this study provides a fundamental foundation for researchers and companies to become familiar with different types of SFCLs. It would be useful to help further studies about the development and the implementation of SFCL for real power systems.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-gtd.2018.6842

On the advance of SFCL: a comprehensive review

A proposal of fast self-acting and recovering magnetic shield type superconducting fault current limiter and the analyses of their characteristics ☆

The current limiting characteristics in a fast self-acting magnetic shield type superconducting fault current limiter were investigated experimentally and compared with the computer simulations. One of the features of the fault current limiter is that the superconducting magnetic shielding body is automatically heated up by the heaters glued on it when a fault occurs. It is revealed that the superconductor is heated up in a short period of time after a fault occurs. Hence current limiting characteristics of high performance are realized. The experimental results are compared with the computer simulations.

An experimental study on a fast self-acting magnetic shield type superconducting fault current limiter

Investigations on current limiting performances in magnetic shield type high Tc superconducting fault current limiter

We examined the possibility of the practical use of a conduction cooled magnetic shield type fault current limiter from the view point of a thermal design. The thermal calculation was carried out with a small model using the Nb/sub 3/Sn wire with low AC loss. We found that the temperature increase of the small model was insignificant. We also confirmed the current limiting operation in an experiment. The conceptual design and the thermal calculation of the conduction cooled fault current limiter for a distribution power system is also discussed in this report.

Thermal design and performance tests of a current limiter with a conduction cooled Nb/sub 3/Sn screen

A stabilizing method for a shorted Nb/sub 3/Sn coil, which will be cooled by a refrigerator at around 10 K and be applied to a magnetic shielding body for a magnetic shield type fault current limiter, is proposed. The stabilizing method is realized by short-circuiting the terminals of the limiting coil through a semiconductor device and keeping the voltage across the Nb/sub 3/Sn coil constant. The stability is studied in a single layer Nb/sub 3/Sn coil operated in a constant AC voltage mode in liquid helium or helium gas. The method has shown to be quite effective for stabilization.

T. Onishi

Papers

A proposal of fast self-acting and recovering magnetic shield type superconducting fault current limiter and the analyses of their characteristics ☆

An experimental study on a fast self-acting magnetic shield type superconducting fault current limiter

Investigations on current limiting performances in magnetic shield type high Tc superconducting fault current limiter

Thermal design and performance tests of a current limiter with a conduction cooled Nb/sub 3/Sn screen

Stability of a shorted Nb/sub 3/Sn coil cooled by a refrigerator for a magnetic shield type fault current limiter