Protection relays used in traction system application utilize impedance protection having parallelogram characteristics with three zones of protection comprising independent R, X values with forward, reverse and independent time settings. These relays are configured to protect the 25 kV single phase 50 Hz traction transmission line which is fed from traction substation with intermediate neutral sections and insulating overlap (IOL). IOL provides further complications when the locomotive moves in this section, where the pantograph located on top of the locomotive may connect the phases of two traction substations, resulting in a wrong phase coupling scenario. Such scenarios should be detected, and the circuit has to be isolated by distance protection relay which senses the fault in the second quadrant of the R-X plane. In addition to this scenario, when regenerative breaking is applied, the moment of inertia will result in the traction motors acting as generators which will result in pumping of current into the traction line resulting in the impedance measurement in second quadrant of the R-X plane. Moreover, the distance relay algorithm is challenged by overloading condition when a locomotive enters into a section. In addition, very high resistive fault would not have sufficient current to drive the impedance relay is the additional challenge. With the availability of latest relay testing equipment, testing of these characteristics has been automated, and the process of mimicking such characteristics and testing it with smart relay testing equipment is discussed in this paper.
Electric Traction Over Head Equipment Protection Using Intelligent Electronic Device
Springer Proceed. in Energy
2021-05-08
7 pages
Article/Chapter (Book)
Electronic Resource
English
Distance protection parallelogram characteristics , Wrong phase coupling , Traction system , Neutral section , Panto flashover , Delta current protection , Regenerative braking , Intelligent electronic device Engineering , Power Electronics, Electrical Machines and Networks , Mechanical Engineering , Energy Materials , Energy
Electronic equipment in electric traction vehicles
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