Inductive Type Fault Current Limiter Research Articles

Energy Storing and Fault Current Limiting in a Unified Superconducting Magnetic Device

This work describes a novel concept for unifying Superconducting Magnetic Energy Storage (SMES) and an inductive-type Fault Current Limiter (FCL). A single superconducting coil is used both as an energy source for the operation of the SMES and as the field source for saturating the magnetic cores in the FCL. A possible geometry model for the implementation of this concept is suggested and a test case in an 11 kV, 10 MVA network is described for a fully, and 50% charged SMES states. Results show that the Saturated Cores FCL exhibits low insertion impedance and high limiting ratio in both scenarios. The unified SMES-FCL device saves major resources by making the superconducting coil a dual-purpose source, thus opening the door for an easier and efficient implementation of SMES and FCL technologies.

Numerical and Experimental Analysis of an Inductive Type Fault Current Limiter Using Short-Circuited 2G Tape

Integrating inductive-type fault current limiters (FCLs) in power grids is envisaged to provide effective protection during severe short-circuit fault occurrences. Numerical simulations are an important class of tools for predicting the performance of these devices under those extreme events. For a proper accuracy of simulations, both electromagnetic and thermal phenomena must be considered. The properties of high-temperature superconducting (HTS) materials, such as electrical resistivity, heat capacity, thermal conductivity, critical current density, and n-index, are strongly dependent on temperature. This is often neglected in transient simulations of devices employing HTS materials, due to unavailability of commercial software easily addressing electromagnetic and thermal interdependence. In this paper, the dynamical behavior of a single-phase inductive-type FCL using a single-turn short-circuited secondary built of HTS second-generation (2G) tape is analyzed by means of a methodology based on the electromagnetic-thermal behavior of the constitutive parts of the FCL. This methodology is fully implemented in MATLAB/Simulink. The transient response during normal and fault operations of line current, primary linked flux, temperature, and current in the 2G tape is simulated and compared with experimental results obtained from a developed prototype. The developed simulation tool provides results in few minutes.

Observation of Transient Behavior of Magnetic Flux in Inductive-type Fault Current Limiter with YBCO Thin Film Disc

Abstract Recently, the installation of fault current limiters (FCLs) in power systems is expected for controlling large short circuit currents. In this study, we focus on inductive-type FCLs having a YBCO superconducting thin film disc that is fabricated by metal-organic deposition. AC currents were injected into the FCL so that the periodic transient behavior of the apparent magnetic flux density around the FCL could be measured by using a pick-up coil. The magnetic flux density exhibited hysteresis when AC current was injected into the FCL. The transition between the conducting states in the YBCO layer was explained by the hysteresis relationship between the magnetic flux density and current.

Multiphysical Finite Element Modeling of Inductive Type Fault Current Limiters and Self Limiting Transformers

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A coupled finite element model of inductive type fault current limiter was developed for transient calculations. The model includes two dimensional finite elements for magnetic field directly coupled with network elements and sequentially coupled three dimensional finite elements for thermal calculations. A computer simulation was developed for implementing the model. Both iron and HTS nonlinearity are handled. The HTS model takes the E-J characteristic into account that depends on flux density and its orientation as well as on the temperature. With 3D thermal calculation the model also handles material inhomogeneity along the perimeter. The simulation results were compared with measurements performed on experimental model of a self limiting transformer. </para>

Influence of Fault Current Limiter on Allowable Interconnecting Time Period of Customer Power System with Synchronous Generator

Distributed generators will be disconnected from a grid with a short-circuit fault to protect the generator and load in the customer system. In order to keep an isolated operation of the generator after the disconnection of customer system from the utility system, the customer system must adjust the power balance between supply and demand. This paper has investigated an influence of a fault current limiter on a probability of isolated operation after the disconnection of customer system with a synchronous generator from a medium voltage feeder. An allowable interconnecting time period, which is a critical time period from the fault occurrence to the isolated operation, has been simulated. It was assumed that the fault current limiter was installed in an interconnecting line between customer system with the synchronous generator and power distribution system. It was found that a resistive type fault current limiter does not improve the allowable interconnecting time period since the consumption power of fault current limiter causes the generator to decelerate. However, it was shown that the allowable interconnecting time period increases owing to the application of inductive type fault current limiter. This is because the active power of load is nearly equal to the generator output.

Inductive type fault current limiter with Bi-2223 thick film on a MgO cylinder

Fault current limiters for electric power systems have been researched. We have studied a inductive type superconducting fault current limiter. The limiter has superconducting cylinder as active element. We developed a high Jc Bi-2223 thick film on a MgO cylinder. Jc was over 5800 A/cm/sup 2/ at 77 K. We made a inductive type superconducting fault current limiter with the Bi-2223 thick film cylinder and investigated limiting performances.