Functions
2.5 Monitoring Functions
SIPROTEC, 7RW80, Manual
C53000-G1140-C233-1, Release date 10.2010
71
2.5.1.5 Broken Wire Monitoring of Voltage Transformer Circuits
Requirements
The measurement of all three phase-to-ground voltages is a requirement for the functionality. If only two phase-
to-phase voltages were measured, it would not be possible to evaluate two of the required criteria.
Task
The „Broken Wire“ monitoring function monitors the voltage transformer circuits of the secondary system with
regard to failure. One distinguishes between single-phase
and two-phase failures.
Mode of Operation / Logic
All three phase-to-ground voltages, the displacement voltage and the displacement voltage are measured. The
required values are calculated for the respective criteria and eventually a decision is made. The resulting alarm
message may be delayed. A blocking of the protection functions is however not effected.
The broken wire monitoring is also active during a fault. The function may be enabled or disabled.
The following logic diagram shows how the broken wire monitoring functions.
Figure 2-14 Logic diagram of the “Broken-wire” Monitoring
To Next Page
Loading...
Need help?
General