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Most industrial technologies are automated by sensitive electric parts such as programmable logic controllers(PLCs) and magnetic contactors which are required high power quality. The voltage sags occur in the non-faulted power distribution feeders during the fault duration. Therefore, voltage causes economic losses in the production process of various companies. To solve the fault current and the voltage sags, the superconducting fault current limiter (SFCL) is in the spotlight. The SFCL where was located on starting point of the feeder improves the reliability of the facility by reducing the fault current. In addition, it compensates the voltage sags on the bus-bar. In this paper, evaluating the voltage sags based on fault location in the power distribution system with the SFCL through PSCAD/EMTDC simulation. Next, the expected the voltage sags frequency is predicted by the reliability analysis technique of the power distribution system. The expected voltage sags frequency of the power distribution feeder is compared with before and after the application of the SFCL. [ABSTRACT FROM AUTHOR]

Power distribution systems should meet demands such as high reliability, efficiency, and penetration of renewable energy generators (REGs) in a smart grid. In general, power distribution systems are radial in nature. One-way power flow is the advantage of a radial system. However, the introduction of REGs causes bidirectional power flow. Furthermore, there are limits to improvements in reliability and efficiency in a radial system. Therefore, the upgrading of primary feeders from a radial to a loop configuration has been considered in the Korea Smart Distribution Project. An advanced power distribution system (APDS), in which primary feeders operate in a loop configuration, has been explored in this paper. First, the design scheme of a conventional power distribution system configuration that adopts distribution automation is introduced. Subsequently, an upgrading scheme of loop configuration using normally opened tie switches and a tie switch selection algorithm for loss minimization are described. Finally, the advantages of the upgraded configuration are reported through case studies. It is observed that the APDS configuration can integrate more REGs from the viewpoint of voltage regulation. An advanced distribution system allowing greater use of REGs will be a major contribution to smart grid implementation. [ABSTRACT FROM PUBLISHER]

The increase of various dispersed generations (DGs) such as wind power and solar cell in a power distribution system has been reported to increase the short-circuit current. In addition, the introduction of the DG in a power distribution system is expected to affect the operation of the protective device as well. The superconducting fault current limiter (SFCL), which has been continuously studied for the reduction of the circuit breaker's power burden, recently starts to be noticed as effective method to solve the fault current problem due to the introduction of the DG. Since the fault current limiting operation of the SFCL and the operations of the protective devices such as the over-current relay or the recloser are affected by the application location of the DG, the study on the protection cooperation of the protective devices with the SFCL considering the application location of the DG in a power distribution system is firstly required. [ABSTRACT FROM PUBLISHER]

The introduction of various dispersed generation (DG) in a power distribution system has caused the short-circuit current to increase, which can make the operation of the protective device deviate from its original set value. Especially, the increase of a short-circuit current in a power distribution system due to the increase of the DG is expected to be required for the related power utilities such as the circuit breaker to be replaced with a larger one. Among the countermeasures to solve the short-circuit problem in a power distribution system considering the increase of the DG, the superconducting fault current limiter (SFCL) has been noticed as one of the promising devices. [ABSTRACT FROM PUBLISHER]

In this study, we analyse the coordination of protective relays between a primary feeder and an interconnecting transformer grounded by using a superconducting fault current limiter (SFCL) of a wind farm. Most wind farms and utility systems are interconnected by a transformer. The winding configuration of most interconnecting transformers is wye grounded-delta. Therefore, the utility-side grounding of the interconnecting transformer can support a new single line-to-ground fault current path. Because the coordination plan of a protective relay in a power distribution system does not consider the new fault path, an unintended relay operation can occur. To overcome this problem, an SFCL is applied to the ground connection of the interconnecting transformer. We analyse the effect of the resistive SFCLs on the coordination of the ground faults using time-domain transient simulation software (PSCAD/EMTDC). [ABSTRACT FROM PUBLISHER]

In this paper, the application method of superconducting fault current limiter (SFCL) for the protection coordination of the protective devices in a power distribution system was analyzed. The SFCL has been announced as better solution among many methods to limit a fault current effectively, which has continuously increased due to more complex network of a power system. However, the application of the SFCL in a power system affects the operation of the protection devices and the protection coordination, which requires the study on the protection coordination of the protective devices considering the application of the SFCL in a power distribution system. [ABSTRACT FROM PUBLISHER]

In this paper, we describes how to coordinate between recloser and fuse in power distribution system with superconducting fault current limiters (SFCL). The recloser and fuses are the main overcurrent protective devices in power distribution system. Universally, to protect against permanent faults, fuses are installed on overhead feeder laterals and the reclosers as a backup protection against temporary faults remove many unnecessary outages. Here, the recloser is set to trip using TCC curve for a temporary fault before any of the fuses can melt. If the fault is a permanent fault, the fuse has to melt just before the last delay trip of the recloser. However, the application of a resistive SFCL in power distribution system affects the recloser- fuse operation and coordination as decreased fault currents. In case that when a permanent fault occurs, the recloser could be locked-out after the last delay trip before the fuses operate. [ABSTRACT FROM AUTHOR]

This paper assesses and analyses the effects of superconducting fault current limiter (SFCL) installed in power distribution system on voltage sags. First of all, resistor-type SFCL is modeled using PSCAD/EMTDC to represent the quench and recovery characteristics based on the experimental results. Next, typical power distribution system of Korea is modeled. When the SFCL is installed in various locations from the starting point to end point of feeders, improvement of voltage sag is evaluated using the Information of Technology Industry Council (ITIC) curve of customer's loads when a fault occur. Finally, future studies needing to apply SFCL to power distribution system are presented [ABSTRACT FROM AUTHOR]