High speed busbar transfer

Permanent availability of electricity is essential for reliable production of a great number of processes in power stations and industrial plants where lots of inductive motor areinstalled. To achieve this, a busbar is normally equipped with two or more independent in-coming power sources to provide the possibility to switch to standby source in case of main source interruption or failure. 

The power supply interruption with tens of millisecond has small impact to rotating loads. Thus, the High Speed Busbar Transfer (HSBT) device helps to control and monitor the progress to ensure the fast but reliable switching-over. It can be initiated manually or automatically. 

Based on the existing world-wide used SIPROTEC 4 platform, the reliability, stability and efficiency of HSBT 7VU683 are guaranteed. Thanks to its powerful and flexible performance, multi functions are integrated into one system, e.g, power supply transfer, relay protection and supervision.

The integrated protective functions are to protect the tie-CB in segmented single busbar diagram against short-circuitand ground fault. The integrated supervision functions are to monitor the voltage phase sequence and voltage secondary circuit , then gives out alarm in case of failure. 

The integrated programmable logic (CFC) allows the users to implement their own functions. The flexible communication interfaces are open for modern communication architectures with control system.

Hardware

• 8 current transfomers
• 8 voltage transformers
• 17 binary inputs
• 18 binary outputs
• Graphic display
• Flush-mounting housing

Communication interfaces

• System port 
  – IEC 61850

  – IEC 60870-5-103 
  

  – PROFIBUS-DP

  – DNP3

  – MODBUS RTU

• Service port

  – DIGSI 4

  – Modem

  – Thermobox

• Front port

  – DIGSI 4

High speed busbar transfer function

• Starting conditions 
  - NORMAL condition 
  - FAULT condition 
  - Inadmissible under-voltage 
  - Inadmissible under-frequency 
  - Inadvertent CB open

• Switching sequences 
  - PARALLEL Auto switching sequence 
  - PARALLEL Half-Auto switching sequence 
  - SIMULTANEOUS switching sequence 
  - SEQUENTIAL sequence

• Transfer modes 
  - FAST transfer mode 
  - REAL-TIME FAST transfer mode 
  - IN-PHASE transfer mode 
  - RES-VOLT transfer mode 
  - LONG-TIME transfer mode

• Single busbar and segmented single busbar supported

• High speed contact with approx.1ms for closing

• Permission of bi-direction switching settable

• Low voltage load-shedding settable

• CB de-coupling when OPEN failed

• NORMAL start locally or remotely

• Manual CB closing to block HSBT

• ON/OFF set locally or remotely

• HSBT test mode supported

Protection functions for tie-CB

• Overcurrent protection

• Ground overcurrent protection

• Overcurrent protection for busbar energization

• Ground overcurrent protection for busbar energization

Monitoring functions

• Self-supervision of the device

• Oscillographic fault recording

• Phase sequence of busbar voltage

• Voltage circuit of busbar and line