Protective scheme

Protective Scheme For Power System

          Hi friends  now we can see the protective action in a power system.Here i am going to explain you the very basic protective scheme.Don't think this is all,the power system contain very complex protective schemes because each and every devices are very costly and dangerous. Here i just illustrate only one P.T and C.T actually each phase has its own C.T and P.T . 

            The C.T is always series to the mains and its secondary should be short circuited(ie.always in a closed circuit).The P.T is always parallel with mains open circuited secondary.In most of the area of power system the C.T is the protecting device, ie we take the current reference . P.T is mainly for the metering of voltage.I think at the generating side only the frequency and voltage terms come into protective action.

            Both the C.T and P.T has many number of secondary  cores for various purposes. Mainly the C.T has dedicated cores for Metering,Protection,Backup Etc..The cores has some standards also like 5P10,.5s etc..according to the accuracy and other parameters.The C.T secondary measures in Ampere. it may be 1A to 5A normally. The P.T secondary measures in voltage, and it is normally 110v AC. we can discuss about C.T and P.T in the next post.........................THANK YOU