Microprocessor based protection for feeders

The main idea of this research is how to design a protective system forfeeders (parallel transmission lines ). This protection system receive theinformation from one side only for two parallel lines . This protective systemuses appropriate Intel 80386-DX microprocessor (as a differential relay) toinitiat tripping, for short circuit in any line of the two parallel lines .This relay works according to a software program which has beenwritten by assembly language which measure the difference between twosamples in digital form, taken from the two lines, through one cycle (20 ms).In normal conditions the output signal would be zero while inabnormal condition for any line the output signal may have a value . If thereare an output signal then the system would tripe the C.B .Finally , this relay operates as a differential protection system fromone side only . With the presence of a communication link, a trip signalwould trip the remote end .This thesis includes four main chapters :-1- Feeder protection using analog relay , unit protection and teleprotectionfor feeders proictions.2- Microprocessor based schemes system architecture and a substation basedcomputer for control and protection .3- Microprocessor updated differential scheme for feeders protection ,assembly language , previous efforts and proposed scheme4- Laboratory setup and results of the proposed scheme and the associateerrors