Overview
The “Busbar differential protection” function is a selective, safe, and quick protection if busbar short circuits should occur and if circuit breakers fail. The protection can be utilized for a variety of busbar configurations in medium, high, and extra-high voltage systems. It is suitable for switchgear with closed iron core or linearized current transformers, and employs a phase-selective method of measurement.
For more detailed information on “Busbar differential protection” function, refer to SIPROTEC 5 devices, V8.30 & higher manuals.
To see other supported functions, click here.
Embedding the Busbar Protection Function
Interaction Check Zone and Busbar Section with Busbar Differential Protection
Setting Parameters
Setting parameters for Busbar protection
| Addr. | Parameter | C | Setting Options | Default Setting |
| Diff.Prot. general | ||||
| _:11821:101 | Diff.Prot. general:Rated object current IrObj | 100 A to 50000 A | 1000 A | |
| _:11821:102 | Diff.Prot. general:Add. trip criterion (p. ph.) | nonexistent existent |
nonexistent | |
| _:11821:103 | Diff.Prot. general:Trip release supervision | off alarm w/o prot. block. protection blocking |
off | |
| _:11821:104 | Diff.Prot. general:Superv. add. trip criterion | off alarm w/o prot. block. protection blocking |
off | |
| _:11821:105 | Diff.Prot. general:Sens. characteristic | nonexistent existent |
nonexistent | |
| _:11821:106 | Diff.Prot. general:Superv.t. BI sens.char. | off on |
off | |
| _:11821:107 | Diff.Prot. general:Measure- ment repetition 1 of 1 Alg. | off on |
off | |
| Check zone | ||||
| _:11911:100 | Check zone:Threshold Idiff | 0.20 I/IrObj to 4.00 I/IrObj | 1.00 I/IrObj | |
| _:11911:101 | Check zone:Threshold Id / sens.char. | 0.05 I/IrObj to 4.00 I/IrObj | 0.25 I/IrObj | |
| _:11911:102 | Check zone:Threshold Is / sens.char. | 0.00 I/IrObj to 25.00 I/IrObj | 4.50 I/IrObj | |
| _:11911:103 | Check zone:Thresh. Is / sens.char/BFP | 0.00 I/IrObj to 25.00 I/IrObj | 5.00 I/IrObj | |
| _:11911:104 | Check zone:Stabilization factor k | 0.10 to 0.80 | 0.50 | |
| _:11911:110 | Check zone:Delay perma- nent release | no yes |
no | |
| Bus zone gen. | ||||
| _:12091:100 | Bus zone gen.:Threshold Idiff | 0.20 I/IrObj to 4.00 I/IrObj | 1.00 I/IrObj | |
| _:12091:101 | Bus zone gen.:Threshold Id /sens.char. | 0.05 I/IrObj to 4.00 I/IrObj | 0.25 I/IrObj | |
| _:12091:102 | Bus zone gen.:Threshold Is / sens.char. | 0.00 I/IrObj to 25.00 I/IrObj | 5.00 I/IrObj | |
| _:12091:103 | Bus zone gen.:Thresh. Is / sens.char/BFP | 0.00 I/IrObj to 25.00 I/IrObj | 5.00 I/IrObj | |
| _:12091:104 | Bus zone gen.:Stabilization factor k | 0.10 to 0.80 | 0.65 | |
| Ext. trip BZ | ||||
| _:11971:100 | Ext. trip BZ:Superv.t. Rel. ext. trip BZ | 0.06 s to 1.00 s | 0.06 s | |
| Cross stab. | ||||
| _:1 | Cross stab.:Mode | off on |
off | |
| _:100 | Cross stab.:Cross.stab. factor BZ | 0.00 to 1.00 | 0.40 | |
| _:101 | Cross stab.:Cross.stab. factor CZ | 0.00 to 1.00 | 0.40 | |
Logic Diagrams & highlights
Formation of the Restraint Current Irest,mod
Standard Characteristic Curve
Sensitive Characteristic Curve
Qualitative Representation of the Primary and Secondary Current in a Transformer Approaching Saturation in the Event of a Fault (Direct-Current Component with a Time Constant of Approx. 50 ms)
Differential and Restraint Current in the Event of an External Short Circuit and Transformer Saturation
Differential and Restraint Current in the Event of an External Short Circuit – Restraint Current Smoothed
Differential and Smoothed Restraint Current in the Event of an Internal Short Circuit
Busbar Differential Protection Trip Logic
Logic Diagram for the Phase-Selective Release Signal
Logic Diagram for the Zone-Specific Release Signal
Disconnector Position Indication
Treatment of the Restraint Current for the Check Zone
