The conventional over-current relaying schemes employed in wind farms for medium voltage collector line protection may encounter challenges related to selectivity and sensitivity. This paper proposes an efficient scheme for relay operation based on transient energy, which is calculated from the current and voltage signals at the medium voltage collector lines (MV-CLs). In this approach, the transient energy values are utilized for fault identification and detection tasks. The effectiveness of the proposed scheme is tested and verified on numerous collector lines of grid driven by doubly fed induction generator (DFIG) based wind energy farms using both fault and non-fault test cases. The results of the proposed work make it evident that the suggested relaying scheme is suitable for efficient fault detection and isolation in wind farm collector lines. Notably, the proposed approach can identify and isolate faults within 20 ms, which is within a single power cycle of a 50 Hz system.