Siemens SIPROTEC 5 User Manual

Logic
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Figure 8-20
Logic Diagram of the Current-Sum Supervision
Slope of the Characteristic Curve
The Slope factor • Σ | I | part takes into account permissible current-proportional transformation errors of
the transformer, which can occur in the case of high short-circuit currents.
The Slope factor and Threshold parameters are used to set the fault-current limit (I
Fmax
) for the current-
sum supervision. The device calculates this fault current limit with the formula:
I
Fmax
= Threshold + Slope factor • Σ| I |
The device uses the current inputs (IA, IB, IC and IN) to calculate:
•
The fault current IF = |
IA + IB + IC + kl• IN|
•
The maximum current Σ| I | = |
IA| + |IB| +| IC| + |kl• IN|
with k
I
taking into account a possible difference from the transformation ratio of a separated ground-current
transformer (I
N
), for example, cable type current transformer.
•
Transformation ratio of residual-current converter: Ratio
N
•
Transformation ratio of phase-current converter: Ratio
ph
Supervision Functions
8.3 Supervision of the Secondary System
388 SIPROTEC 5, Fault Recorder, Manual
C53000-G5040-C018-5, Edition 11.2017

Siemens SIPROTEC 5 Specifications

General

Series	SIPROTEC 5
Communication Protocols	IEC 61850, DNP3, Modbus
Cybersecurity	Role-based access control, secure communication
Modular Design	Yes
Hardware Redundancy	Optional
Operating Temperature	-25°C to +70°C
Digital Inputs	Configurable, number depends on I/O modules
Digital Outputs	Configurable, number depends on I/O modules
Analog Inputs	Configurable, number depends on I/O modules
Current Transformer Inputs	Configurable, number depends on I/O modules
Voltage Transformer Inputs	Configurable, number depends on I/O modules
Time Synchronization	IRIG-B, SNTP, PTP
Protection Functions	Overcurrent, Differential, Distance, Over/Under Voltage, Frequency
Housing	19-inch Rack Mount
Dimensions	Depends on module configuration
Weight	Depends on module configuration
Voltage Input	24V DC, 48V DC, 110V DC, 125V DC, 220V DC, 250V DC