Tests and recovery under load simulations of a novel bifilar resistive SFCL having undulated shape configuration

Abstract

Power systems are becoming more interconnected and complex. The distributed generation expands and spreads across the grids, reducing the distance between the load and the generation. In addition, several substations are aging after decades of operation and their equipment struggle to sustain the ever increasing fault levels. In this context, the fault current limiter (FCL) arrived as a solution to mitigate this problem. Considering the FCL devices, the resistive superconducting FCL (R-SFCL) is the most mature technology with potential to be produced in mass scale, due to its ability to quickly change its impedance during a fault current and its high current density capacity. In this paper, a novel R-SFCL topology is presented, which has an unique design that allows a compact size and the possibility of modulated assembly. These characteristics enable setups for various voltage and current levels. One advantage of this topology is the compromise between volume and high heat exchange that can reduce the recovery time under load. One bench prototype was modeled using the thermal–electrical analogy implemented in ATPDraw, tested in two different labs. Tests were performed at faults levels of 12 kA peak , 5 kA rms and 2.7 kA rms for 137 V. Measured and simulated results were compared, resulting in a relative error of less than 12%. Two contributions can be highlighted: the new design of the R-SFCL and the inclusion in the convection heat exchange model curves for the heating (during the quench) and cooling (after fault), which allows to predict the recovery under load.

Multi-objective optimization for the superconducting bias coil of a saturated iron core fault current limiter using the T-A formulation

“…The current density is integrated over this cross-sectional area, according to equation (11), to force the desired net current value through the tape. As shown in figure 5, the current vector (T) is normal to the conductor's face, so that equation ( 11) becomes (12). In order to impose the current density calculated by the T formulation into the A-V formulation, a Neumann boundary condition is added by equation (13).…”

“…Due to their capacity to reduce the short circuit current level in the electrical power system, the literature presents several studies about fault current limiters (FCL). Among many configurations of the FCLs [1][2][3][4][5][6][7], the technologies applying superconducting materials can be a useful solution in the future [8][9][10][11][12].…”

A coupling method of the superconducting devices modeled by finite element method with the lumped parameters electrical circuit

“…Base on this average resistivity the resistance of a single turn can be calculated as in equation (20). It is stressed that this is the resistance of the superconductor layer only.…”

“…As discussed in section 3.1, only the superconductor layer is included in the FEM model and all other tape materials are neglected. The total resistance of the superconducting coil is calculated through the sum of the resistancesequation (20). Then, the equivalent resistance that is seen by the DC power supply during the iteration k is calculated as in equation ( 21):…”

Essential Material Knowledge and Recent Model Developments for REBCO-Coated Conductors in Electric Power Systems

“…Electrical equipment using High-Temperature Superconducting (HTS) materials are reaching maturity after more than two decades of research and development. Nowadays, devices like Fault-Current Limiters (FCL) [1][2][3][4][5][6], power cables [7,8], and electric machines [9,10] have been built, and in some cases, installed in electric networks. The HTS materials with the most potential to address simultaneously cost and technical requirements are the second generation (2G) wire (or tape).…”