1. Surge current protection using superconductor
Made by
Abhishek Walter Paul
11104EN072

2. INTRODUCTION
Modern power system are growing fast with more generators, transformers and large network in the system. whenever a fault occurs there is a need for the protection of these system. Here we discussed the use of superconductor as protective device for surge current protection. Superconductors conduct electricity, offering zero resistance below certain temperature. We study different types of superconductor as fault current limiter and their working

9. BASIC DEFINITION
A Fault Current Limiter (FCL) is a device which limits the prospective fault current when a fault occurs (eg in a power transmission network).
The term is generally applied to superconducting devices, whereas non-superconducting devices (such as simple inductors or variable resistors) are typically termed Fault Current Controllers.
For example, the ground fault circuit interrupter is commonly used in residential installations.

10. Fault-current limiters using high temperature superconductors
Solution to controlling fault-current levels on utility distribution and transmission networks.
unlike reactors or high-impedance transformers, will limit fault currents without adding impedance to the circuit during normal operation.
Development of superconducting fault-current limiters is being pursued by several utilities and electrical manufacturers around the world, and commercial equipment is expected to be available by the turn of the century.

11. “THE PROBLEMS”

12. Other common system changes which can result in a fault current problem
additional generation from cogenerators and independent power producers raises the fault duty throughout a system.
old equipments become underrated through system growth; some equipment, such as transformers in underground vaults or cables, can be very expensive to replace.
customers request parallel services that enhances the reliability of their supply but raises the fault duty.

13. Superconductive FCL
Removes design constraints by presenting a varying impedance in the system which changes with operating condition.
normally operate with low impedance and are "invisible" components in the electrical system.
During fault, limiter inserts impedance into the circuit and limits the fault current.
development of high temperature superconductors (HTS) enables the development of economical fault-current limiters

14. EXAMPLE

15. Think of Fault Current Limiters (FCLs) as advanced and large-scale surge protectors capable of protecting large portions of the electric power grid. Limits and regulates the amount of current moving through transmission and distribution system under abnormal conditions.

16. HANDLING GROUND FAULT

17. TYPES OF SUPERCONDUCTIVE FCL
The Series Resistive Limiter
simplest superconducting limiter concept
exploits the nonlinear resistance of superconductors in a direct way
in its resistive state it can also be used as a trigger coil, pushing the bulk of the fault current through a resistor or inductor
 limits the energy that must be absorbed by the superconductor

18. The Inductive Limiter
a resistive limiter on a transformer secondary, with the primary in series in the circuit.
yields a limiter suitable for high-current circuits.
Inductive Fault Current Limiters for Grid Protection
50% reduction of fault currents
¼ cycle reaction time
handles long duration faults and breaker reclosure attempts