Siemens 7SJ85 - Overcurrent Protection for Capacitor Banks; Overview; Overcurrent Protection, Phases for Protection of RLC Filter-Circuit Elements; Structure of the Function

Overcurrent Protection for Capacitor Banks
Overview
You can use the following overcurrent protection function types in the Capacitor bank function group:
•
Overcurrent protection, phases with phase-segregated operate indications for short-circuit protection
in the area between the busbar and the capacitor and for protecting against overload of a subbank.
•
Overcurrent protection, phases for protection against overload of RLC filter circuit elements (Over-
curr. -3ph RLC)
•
Overcurrent protection, ground as protection or backup protection in the event of ground faults
Figure 5-17 in chapter 5.4.2 Structure of the Function Group shows
•
The standard protection functions you can use in the Capacitor bank function group.
•
The specific protection functions that are available for protecting a capacitor bank.
•
The assignment of protection functions to the interfaces of the function group.
Figure 5-15 in chapter 5.4.2 Structure of the Function Group shows the assignment of the interfaces in the
Capacitor bank function group to the measuring points of the device with reference to an example.
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NOTE
Starting from V07.30, the function type 50/51 OC-3ph 1p is no longer offered in the DIGSI 5 global library
in the function group Capacitor bank. Instead you can use now the standard overcurrent protection func-
tion Overcurrent protection, phases – advanced to apply phase-segregated operate indications.
Overcurrent Protection, Phases for Protection of RLC Filter-Circuit Elements
Structure of the Function
In the Capacitor bank function group, the Overcurr. -3ph RLC function is based on the standard overcurrent
protection function Overcurrent protection, phases – advanced.
The Overcurr. -3ph RLC function differs from the standard protection function as follows:
•
Superordinate measuring-point selection
•
Selecting whether the rated current of the capacitor bank or of the protected object (for example, reactor
or resistor) is taken as reference value
•
Setting the rated current of the protected object (for example, reactor or resistor) within the function if
necessary
•
Functional measured values of connected phase currents
7.2
7.2.1
7.2.2
7.2.2.1
Capacitor Bank Protection
7.2 Overcurrent Protection for Capacitor Banks
SIPROTEC 5, Overcurrent Protection, Manual 969
C53000-G5040-C017-8, Edition 07.2017