Give protection scheme used for 25kV catenary protection for AC traction.

Give protection scheme used for 25kV catenary protection for AC traction.
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Answer :

Protection Scheme Used for 25kV Catenary Protection for AC Traction: As shown in the figure below the scheme consists of 1) MHO relay that makes use of the impedance phase angle to get proper discrimination for distant faults on it. It consists of PT, CT on 25 kV catenary and variable capacitors for phase angle adjustment. 2) Over current relay. 3) Under voltage relay for low voltage protection.

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