Download Surge Protection Using Superconductors

Surge current protection using
superconductor
Made by
Abhishek Walter Paul
11104EN072
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
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.
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.
“THE PROBLEMS”
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.
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
EXAMPLE
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.
HANDLING GROUND FAULT
TYPES OF SUPERCONDUCTIVE FCL
• The Series Resistive Limiter
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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
• The Inductive Limiter
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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