05-10-2016, 03:24 PM
1457935717-surgecurrentprotectionusingsuperconductorpptmahesh140326104357phpapp021.pptx (Size: 512.04 KB / Downloads: 26)
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.
WHAT IS SURGE CURRENT
The maximum instantaneous input current drawn by an electrical device when first it is turn ON , is defined as surge current it is also known as inrush current or input surge current or switch on surge. Inrush current can be as high as 100 times the normal steady state current and lasts for less than half a normal 60Hz cycle.
WHAT IS SUPERCONDUCTOR
An element, inter-metallic alloy or compound that will conduct electricity without resistance below a certain temperature. The dutch physicist HEIKE KAMERLINGH ONNES of leiden university was the first person to observe superconductivity in mercury. Superconductivity is a phenomenon of exactly zero electrical resistance certain materials when cooled below a characteristics critical temperature.
TYPES OF SUPERCONDUCTOR
Low temperature superconductor
example :- lead and mercury-common LTS other LTS are Ti, V, Zr, Nb etc.
High temperature superconductor
exmaple :- YBCO, BSCCO, LSCO etc.
FAULT CURRENT LIMITER
A fault current limiter is a device which limit prospective fault current when a fault occur. Generally FCL are superconductor FCL.
Two major categories of FCL
(1) resistive
(2) inductive