2.25
Function Control and Circuit Breaker Test
2.25.1
Function Control
The function control is the control centre of the device. It coordinates the sequence of the protection and ancil-
lary functions, processes their decisions and the information coming from the power system.
Applications
• Line energization recognition,
• Processing of the circuit breaker position,
• Open Pole Detector,
• Fault detection logic,
• Tripping logic.
2.25.1.1 Line Energization Recognition
During energization of the protected object, several measures may be required or desirable. Following a
manual closure onto a short-circuit, immediate trip of the circuit breaker is usually desired. This is done, e.g. in
the overcurrent protection, by bypassing the delay time of a current stage. For every short-circuit protection
function which can be delayed, at least one stage can be selected that will operate instantaneously in the event
of a closing, as mentioned in the relevant sections. See also Section 2.1.4.1 side title „Circuit breaker status".
The manual closing command must be indicated to the device via a binary input. In order to be independent
of the duration that the switch is closed, the command is set to a defined length in the device (adjustable with
the address 1150 SI Time Man.Cl). This setting can only be changed using DIGSI at Additional Settings.
Figure 2-218 shows the logic diagram.
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
2.25 Function Control and Circuit Breaker Test
Functions
443