5、ltageratingof220kV and above powersystem, inordertoensurethe stabilityof paralleloperation and increasethetransmission power, protection requirements inmanycases without delayfromline fault onbothsidesof theprotectedcircuitis removed atanypoint. WXHJ-
6、803 is atypical opticalfiber longitudinal differentialprotectiondevice, throughtheopticalfiber electricquantityis transmittedto eachend toend, willcomparethe electricalquantities ofbothends, to judgethefault within the scopeofprotection or line, todec