This study examines the implementation of the Permissive Overreach Transfer Trip (POTT) Echo scheme with the activation of the Weak-End Infeed (WEI) function on distance protection systems in a 150 kV transmission network to enhance protection reliability and selectivity, especially at substations with weak infeed currents. Before WEI activation, the protection system experienced delays or failures in detecting faults, particularly for faults in zone 2, where the relay tripped with a delay instead of achieving a desired reclose, thereby extending the Transmission Line Outage Duration (TLOD). After WEI activation, test results showed that the relay provided an instantaneous trip response, and the autoreclose function operated after 1000 ms, significantly reducing TLOD. The success of the echo signal ensured smooth communication between relays, supporting efficient protection coordination. Moreover, the selectivity function remained intact. The implementation of this scheme has proven to enhance the reliability of the protection system, offering a more stable and responsive solution for addressing the challenges posed by weak infeed currents.
 
Keywords: POTT, Echo, Weak-End Infeed, Distance Protection, Autoreclose
 
ABSTRAK
Penelitian ini membahas implementasi skema Permissive Overreach Transfer Trip (POTT) Echo dengan aktivasi fungsi Weak-End Infeed (WEI) pada sistem proteksi jarak di jaringan transmisi 150 kV untuk meningkatkan keandalan dan selektivitas proteksi, khususnya di gardu induk dengan arus infeed lemah. Sebelum aktivasi WEI, sistem proteksi mengalami keterlambatan atau kegagalan dalam mendeteksi gangguan, terutama pada gangguan di zona 2, di mana relay memicu trip dengan waktu tunda, meskipun reclose diharapkan, sehingga memperpanjang durasi gangguan (Transmission Line Outage Duration - TLOD). Setelah aktivasi WEI, hasil pengujian menunjukkan bahwa relay memberikan respon trip instan, dan fungsi autoreclose dapat bekerja setelah 1000 ms, mengurangi TLOD secara signifikan. Keberhasilan sinyal echo memastikan komunikasi antar relay berjalan lancar, mendukung koordinasi proteksi yang efisien. Selain itu, fungsi selektivitas tetap terjaga. Penerapan skema ini terbukti meningkatkan keandalan sistem proteksi, memberikan solusi yang lebih stabil dan responsif dalam menghadapi tantangan arus infeed lemah.