Overcurrent protection as backup protection for line protection

Overcurrent protection as backup protection for line protection – SIPROTEC 7SJ86

SIPROTEC 7SJ86

The SIPROTEC 7SJ86 overcurrent protection has specifically been designed as backup or emergency protection for the line protection devices. With its modular structure, flexibility and the powerful DIGSI 5 engineering tool, the SIPROTEC 7SJ86 device offers future-oriented solutions for protection, control, automation, monitoring and PQ basic.

Features & functions

Overcurrent protection as backup protection for line protection SIPROTEC 7SJ86

Features

Main function:

  • Overcurrent protection (V/inverse-time overcurrent protection)

Tripping:

  • 3-pole

Inputs and outputs:

3 predefined standard variants with 

  • 4 current transformers, 
  • 4 voltage transformers,
  • 11 to 23 binary inputs,
  • 9 to 25 binary outputs

Hardware flexibility:

  • Flexibly adjustable and expandable I/O quantity structure within the scope of the SIPROTEC 5 modular system.

Housing width:

  • 1/3 × 19 inches to 2/1 × 19 inches

As standard:

Functions

DIGSI 5 permits all functions to be configured and combined as required.

  • Overcurrent protection as backup / emergency line protection for all voltage levels with 3-pole tripping
  • Optimized tripping times due to directional comparison and protection data communication
  • Detection of ground faults of any type in compensated or isolated electrical power systems using the following functions: 3I0>, V0>, transient ground fault, cos φ, sin φ, dir. detection of intermittent ground faults, harmonic detection and admittance measurement
  • Ground fault detection using the pulse detection method
  • Fault locator plus for accurate fault location with inhomogenous line sections and targeted automatic overhead-line section reclosing (AREC)
  • Arc protection
  • Automatic frequency relief for underfrequency load shedding, taking changed infeed conditions due to decentralized power generation into consideration
  • Overvoltage and undervoltage protection
  • Frequency protection and frequency change protection for load shedding applications
  • Power protection, configurable as active or reactive power protection
  • Protection functions for capacitor banks, such as overcurrent, overload, current unbalance, peak overvoltage, or differential protection
  • Directional reactive power undervoltage protection (QU protection)
  • Detection of current and voltage signals up to the 50th harmonic with high accuracy for selected protection functions (such as thermal overload protection) and operational measured values
  • PQ-Basic: voltage unbalance; voltage changes: overvoltage, dip, interruption; TDD, THD and Harmonics
  • Control, synchrocheck and switchgear interlocking protection
  • Circuit-Breaker Failure Protection
  • Circuit breaker reignition monitoring
  • Graphical logic editor to create powerful automation functions in the device
  • Single-line representation in small or large display
  • Integrated electrical Ethernet RJ45 for DIGSI 5 and IEC 61850 (reporting and GOOSE)
  • Up to 4 pluggable communication modules, usable for different and redundant protocols (IEC 61850-8-1, IEC 61850-9-2 Client, IEC 60870-5-103, IEC 60870-5-104, Modbus TCP, DNP3 serial and TCP, PROFINET IO, PROFINET IO S2 redundancy)
  •  Virtual network sharing (IEEE 802.1Q - VLAN)
  • Serial protection data communication via optical fibers, two-wire connections and communication networks (IEEE C37.94, and others), including automatic switchover between ring and chain topology
  • Reliable data transmission via PRP and HSR redundancy protocols
  • Extensive cybersecurity functionality, such as role-based access control (RBAC), protocolling security-related events, signed firmware or authenticated network access IEEE 802.1X
  • Simple, quick and secure access to the device via a standard Web browser to display all information and diagnostic data, as well as vector diagrams, single-line and device display pages
  • Phasor Measurement Unit (PMU) for synchrophasor measured values and IEEE C37.118 protocol
  • Time synchronization using IEEE 1588
  • Powerful fault recording (buffer for a max. record time of 80 sec. at 8 kHz or 320 sec. at 2 kHz)
  • Auxiliary functions for simple tests and commissioning
  • Flexibly adjustable I/O quantity structure within the scope of the SIPROTEC 5 modular system

 

Applications

  • Backup and emergency protection for line protection
  • Detection and selective 3-pole tripping of short circuits in electrical equipment of star networks, lines with infeed at 1 or 2 ends, parallel lines and open-circuited or closed ring systems of all voltage levels
  • Used in switchgear with breaker-and-a-half layout configuration
  • Detection of ground faults in isolated or arc-suppression-coilground systems in star, ring, or meshed arrangement
  • Serial protection communication with SIPROTEC 5 and SIPROTEC 4 devices over different distances and physical media, such as optical fiber, two-wire connections, and communication networks 
  • Phasor Measurement Unit (PMU)
  • Acquisition and recording of power quality data in the medium voltage and subordinate low voltage network

Benefits

  • Safety due to powerful protection functions
  • Purposeful and easy handling of devices and software thanks to a user-friendly design
  • Highest availability even under extreme environmental conditions  by “conformal coating“ of electronic boards
  • Cybersecurity in accordance with NERC CIP and BDEW Whitepaper requirements
Downloads

Downloads