can u send me information about surg current protection using superconductors........
A surge or fault current limiter is a device that uses superconductors to instantaneously limit or reduce unanticipated electrical surges that may occur on utility distribution and transmission networks.
Need for surge current limiter
lightning or downed power lines, occurs, a large surge of power can be sent through the grid resulting in a fault. Serious faults can generate surge currents more than one hundred times the normal operating currents. These faults can result in damage to expensive grid-connected equipment.new generating facilities and network upgrades increase the chances for it. FCL's eliminate or greatly reduce the
financial burden on the utilities by reducing the wear on circuit breakers and protecting other expensive equipment.
Fault/surge current limiter benefits
-safety, reliability, and power quality.
-cost for circuit breakers and fuses can be reduced
-life of transformers extended
-Reduce or eliminate wide-area blackouts, far fewer localized disruptions,
-Avoid split buses,
-Higher system reliability
-Provide protection to T&D equipment,
-Enhance grid stability.
-Reduce voltage dips
SUPERCONDUCTING FAULT CURRENT LIMITERS
(SCFCLs) can reduce the fault currents to an acceptable
values. They must not react to a switching surge.Trigger current level of an SCFCL should be
determined by the relation between peak value and duration of
the current level like a protection relay system. The device was based on Siemens' proprietary superconductor switching module technology, which uses coils fabricated with AMSC's proprietary 344S superconductors.
344 superconductors, which have the architecture of what are generically known as second generation (2G) high temperature superconductor wires. They comprise the basic 2G HTS wire architecture clad with ultra-thin strips of copper. When laminated with stainless steel, it becomes 344S superconductors. They have higher power density and efficiency compared with similar copper-based wire products. Commercialization of fault current limiters for power transmission and distribution grids is to be performed by these companies.
The final testing of the device by AMSC(American Superconductor Corporation - NASDAQ: AMSC) and Siemens was conducted on a 2 mega-volt-ampere (2 MVA) FCL. The single-phase laboratory test was based on a superconductor switching module fabricated by Siemens from 344S superconductors.The system operated at a voltage of 7.5 kV(widely used in distribution). It limited the current during a fault by up to 25 times.
hey i need to give a 25 page full seminars report and presentation on the same
i need to include the info on technology and what AMERICAN SUPERCONDUCTORS AND SIEMENS ARE DOING IN THIS FIELD
present scenario as superconductors are not being used in india
plz help me
Surge protection using superconductors
The recent growth of power circuit capacities has caused fault currents to increase. Since the protection of power systems from the fault currents is very important, it is needed to develop a fault current limiter. A fault current limiter is required to assure (1) rapid reaction to fault currents, (2) how impedance in normal operation and (3) large impedance during fault conditions. A super conducting fault current limiter (SCFCL) can meet these requirements superconductors, because of their sharp transition from zero resistance at normal current to finite resistance at higher current densities, are tailor-made for use in FCLs. Super conductors are of two types-high temperature superconductors (HITS) and low temperature superconductor (LTS). The HTS are substances that lose all resistance below temperature main tamable by liquid nitrogen. LTS are substances that lose all receptivity close to 4k, a temperature attainable only using by using liquid helium. Cost of cooling LTS (which are mostly metals, alloys and intermettalics) makes their use in many applications commercially impractical. HTS material available are all made of bismuth (BSCCO) or yttrium-cup rate (YBCO). So far, various types of SCFLS have been developed (resistance, shield core type, hybrid etc.). The SCFCL offers efficient advantages to power system and opens up a major application for superconducting materials.
send me ppt about my seminars.