Busbar protection SIPROTEC 7SS85

Busbar protection SIPROTEC 7SS85

Product Overview

The SIPROTEC 7SS85 busbar protection is a selective, safe and fast protection against busbar short circuits in medium, high, and very high voltage systems.

Description :

SIPROTEC 5 busbar protection – the best solution for all customer requirements wherever energy flows.
The proven, fast and secure algorithms of SIPROTEC 7SS52 combined with the flexible, scalable, open and user-friendly SIPROTEC 5 platform gave birth to the new benchmark of busbar protection: SIPROTEC 7SS85.

If you  are looking for a successor of the SIPROTEC 7SS52, IEC 61850 interoperable and open solution in line with your digital substation strategy and cost-efficient enhancement of your grid resilience with busbar protection, the SIPROTEC 7SS85 is the right solution for you.

Benefits :

  • Fast and secure – Proven and reliable algorithms since 1989
  • Cyber Secure – Compliant with NERC CIP and BDEW Whitepaper-Requirements
  • Robust – Highest availability even under extreme environmental influences
  • Consistent – One platform, one device, one configuration tool
  • User-friendly – Configuration by the user during the entire service life
  • Clearly structured – Full graphical engineering and online plant visualization with DIGSI 5
  • Flexibility – Centralized, decentralized or combined (hybrid) Architecture
  • Universal – SIPROTEC 5 protection devices and merging units as bay unit
  • Powerful – Busbar protection device as central feeder protection
  • Economical – Extension of the protection system with busbar protection
  • Interoperable – Compatible with Merging Units according to IEC 61850 Rev.2.1

The performance and flexibility of the SIPROTEC 7SS85 allow the implementation of a wide range of customer-specific secondary technology concepts and solutions, such as:

  • IEC 61850 compatible and interoperable distributed busbar protection
  • Cost-efficient extension of the protection system with busbar protection
  • Successor solution for the power-proven SIPROTEC 7SS52

Functions :

All functions can be configured as required with DIGSI 5. Using some functions requires the appropriate number of free function points to be available in the device. The function point calculator in the online configurator provides support in the determination of the required number of function points for your device. The necessary function points are also shown during project engineering with DIGSI 5.

Characteristic Key Values of SIPROTEC 7SS85

  • Phase-selective measurement and display
  • Selective tripping of faulty bus zones
  • Disconnector-independent check zone as additional tripping criterion
  • Shortest tripping times to ensure network stability and minimize damage to the system- Central busbar protection: 3 ms/7ms (Relais Typ HS/Typ F)

    – Decentral busbar protection: 8 ms/12 ms (Relais Typ HS/Typ F)

  • Highest stability in case of external faults – even in case of transformer saturation – through stabilization
    with flowing currents
  • Operate curve with freely adjustable characteristic curve sections
  • Additional operate curve with increased sensitivity for low-current errors, for example in resistance-grounded
    power systems
  • Fast recognition of internal and external errors requires only 2 ms of saturation-free time of the current transformer
  • Using closed iron core or linearized current transformers in a plant is possible
  • Adaptation of different current transformer ratios per parameterization
  • Straight-forward dimensioning of current transformers and stabilization factor
  • Three interacting methods of measurement allow minimum tripping times after busbar faults and ensure maximum stability in case of large short-circuit currents
  • The integrated circuit-breaker failure protection recognizes circuit breaker faults in the event of a busbar short
    circuit and provides a trip signal for the circuit breaker at the line end. The adjacent busbar trips if a coupling circuit breaker fails
  • There is extensive monitoring of current transformer circuits, measured value acquisition and processing, and trip circuits. This prevents the protection from subfunction, which reduces the effort for routine checks.
  • Various control possibilities, such as bay out of order, acquisition blocking from disconnectors and circuit breakers, blocking of protection zones or circuit-breaker failure protection, make the adaptation to operationally-caused special states of your plant easier
  • 1/3-pole or 3-pole circuit-breaker failure protection using the integrated disconnector image for tripping
    all circuit breakers of the busbar section affected
  • End-fault protection for the protection of the section between circuit breaker and current transformer for feeders and bus couplers
  • Direct tripping of protection zones through external signals
  • Release of the tripping of a protection zone through additional external signals
  • Release of tripping through additional, external phase-selective signals
  • Cross stabilization against overfunctions in case of transformer influence on the secondary side
  • Bus coupler differential protection for fault clearing in couplers with two current transformers.
  • With decentralized busbar protection, any feeder protection function can be additionally implemented by using any modular SIPROTEC 5 device as a bay device.
  • Extensive cyber security functionality, such as role-based access control (RBAC), protocolling security-related events, signed firmware or authenticated network access IEEE 802.1X

Function library and application templates

The flexibility of the SIPROTEC 7SS85 allows for the protection of a large number of possible system configurations. In place of application templates, DIGSI 5 makes a comfortable, fully graphical interface for complete engineering of your busbar protection available.

More Information


+66 2 063 5262-3, +66 83 440 1404