Subcycle distance protection relay suitable for lines of any voltage level with any configuration: overhead or underground, single or parallel circuits

The ZLF includes all the protection, control and measurement functions for a power line, with or without series compensation, single or double breaker, and single pole or three pole tripping.

Eight distance zones with Mho or quadrilateral characteristic, complemented with load encroachment and power swing, fuse failure, close onto fault, and saturation detectors provide great security and dependability even in the most adverse conditions.

The distance and overcurrent units can operate according to the following schemes: DTT, PUTT, POTT, DCUB and DCB.

Weak infeed logic and current inversion blocking are also included.

Distance Protection Relay Key Features

• Subcycle Operation: Distance algorithms based on half-cycle windows combined with robust solid-state trip outputs permit sub-cycle trip times for faults located within 75% of the zone.
• Mutual Coupling Compensation: In parallel circuits is compensated by measuring the neutral current of the parallel line.
• Communication between IEDs
  • Up to 4 ports: Communication without redundancy with up to 4 remote ends or with redundancy with up to 2 remote ends.
    Selectable speed: from 1 x 64 kbit/s up to 2 Mbit/s.
  • Multimode or single mode FO interfaces (optional SFPs).
  • Communication with SDH multiplexers via C37.94 or via ZIV model F2MUX optical-electric converter that
    integrates G703 and V35 output interfaces.
  • Up to 16 digital signals can be exchanged between terminals to implement teleprotection schemes.

General characteristics of the “ZIV e-NET flex family” protection relays:

• Powerful programable logic. 9 2000 event log. Up to 100 oscillography seconds.
• Alphanumeric or graphic display.
• 160 DI, 80 DO, and 22 LEDs.
• Bonding, RSTP, PRP and HSR Redundancy.
• IEC 61850 Ed.2, DNP3.0, Modbus RTU and PROCOME Protocols.
• Native process bus. Analog input cards operate as Merging Units for the CPU. Synchronized samples at 4800 Hz (as per IEC 61869-9).
• Cybersecurity in accordance with IEC 62351, IEC 62443 and IEEE 1686-2013 standards. RBAC, secure keys, physical and logical port disabling, cybersecurity event log, securing of management protocols (PROCOME, HTTPS, SFTP, SSH), remote authentication (LDAP, RADIUS) and digital firmware securitization.
• Time synchronization by IRIG-B, SNTP and PTP (Ordinary Clock / Transparent Clock).