Siemens Siprotec 4 SIPROTEC 7SA522 Protection Relay

The SIPROTEC 7SA522 relay provides full-scheme distance protection and incorporates all functions usually required for the protection of a power line. The relay is designed to provide fast and selective fault clearance on transmission and sub-transmission cables and overhead lines with or without series capacitor compensation. The power system star point can be solid or resistance grounded (earthed), resonant-earthed via Peterson coil or isolated.The SIPROTEC 7SA522 is suitable for single-pole and three-pole tripping applications with and without the (pilot) protection schemes.The SIPROTEC 7SA522 incorporates several protective functions usually required for transmission line protection:-High-speed tripping time-Suitable for cables and overhead lines with or without series capacitor compensation-Self-setting power swing detection for power swing frequencies up to 7 Hz- Digital relay-to-relay communication for two and three terminal topologies-Adaptive auto-reclosure (ADT)

PROTECTION FUNCTIONS

• Non-switched distance protection with 6 measuring systems (21/21N)
• High resistance ground (earth)-fault protection for single and three-phase tripping (50N, 51N, 67N)
• Tele (pilot) protection (85)
• Fault locator (FL)
• Power swing detection / tripping (68/68T)
• Phase-overcurrent protection (50/51)
• STUB bus overcurrent protection (50STUB)
• Switch-onto-fault protection (50HS)
• Over/undervoltage protection (59/27)
• Over/underfrequency protection (81O/U)
• Auto-reclosure (79)
• Synchro-check (25)
• Breaker failure protection (50BF)

CONTROL FUNCTIONS

• Commands for control of CB and isolators

MONITORING FUNCTIONS

• Trip circuit supervision (74TC)
• Self-supervision of the relay
• Measured-value supervision
• Event logging/fault logging
• Oscillographic fault recording
• Switching statistics

FRONT DESIGN

• User-friendly local operation with numeric keys
• LEDs for local alarm
• PC front port for convenient relay setting
• Function keys

COMMUNICATION INTERFACES

• Front interface for connecting a PC
• System interface for connecting to a control system via various protocols
  – IEC 61850 Ethernet
  – IEC 60870-5-103 protocol
  – PROFIBUS-FMS/-DP
  – DNP 3.0
• 2 serial protection data interfaces for tele (pilot) protection
• Rear-side service/modem interface
• Time synchronisation via IRIG B or DCF77 or system interface

HARDWARE

• Binary inputs: 8/16/24
• Output relays: 16/24/32
• High-speed trip outputs: 5 (optional)

SIPROTEC 4 leads the way in integrating protection, control, measurement, and automation functions in one device. The homogenous system platform, the unique DIGSI 4 engineering program, and extensive experience of more than a million successfully operating devices in the field worldwide – thanks to these unique advantages, SIPROTEC 4 enjoys top recognition among users worldwide. SIPROTEC 4 is the industry standard for digital protection technology today in all fields of application.