Siemens SIPROTEC 7UT613 series Manual page 42

2 Functions
Forward Power
Monitoring
Undervoltage
Protection
Overvoltage
Protection
Frequency
Protection
Circuit-breaker
Failure Protection
Circuit-breaker
Failure Protection 2
Measuring
Location Discon-
nection
Measured Value
Monitoring
Trip Circuit Super-
vision
42
former, allows for a reasonable calculation of the active power. The definition of the
reverse direction is explained in detail elsewhere.
The forward power monitoring (address 151 FORWARD POWER) can monitor a protect-
ed object with regard to undershooting as well as exceeding of a preset active power.
It can only be used in three-phase protected objects, thus not at address 105 PROT.
OBJECT = 1 phase transf. or 1ph Busbar. The forward power monitoring re-
quires that the device is connected to a voltage transformer set and, together with a
connected current transformer, allows for a reasonable calculation of the active power.
The definition of the forward direction is explained in detail elsewhere.
Undervoltage protection (address 152 UNDERVOLTAGE) detects voltage dips in elec-
trical machines and avoids inadmissible operating states and possible loss of stability
in electrical devices. It can only be used in three-phase protected objects, thus not at
address 105 PROT. OBJECT = 1 phase transf. or 1ph Busbar. It is normally
only possible in device variant that have a voltage measuring input.
The overvoltage protection (address 153 OVERVOLTAGE) protects the system from
impermissible voltage increases, thus avoiding damage to its insulation. It can only be
used in three-phase protected objects, thus not at address 105 PROT. OBJECT = 1
phase transf. or 1ph Busbar. It is normally only possible in device variant that
have a voltage measuring input.
The frequency protection (address 156 FREQUENCY Prot.) has the task to detect
increased or decreased frequencies in the power station sector. It can be applied, for
example, as load shedding in the system. It can only be used in three-phase protected
objects, thus not at address 105 PROT. OBJECT = 1 phase transf. or 1ph
Busbar. As the frequency is derived from the measuring voltage, this is only possible
in device versions with voltage measuring inputs.
The circuit-breaker protection (address 170 BREAKER FAILURE) is applicable to any
circuit breaker. The assignment is carried out at a later stage. Note that in a single-
phase busbar protection (address 105 PROT. OBJECT = 1ph Busbar) it is not pos-
sible.
7UT613/63x provides a second circuit-breaker failure protection (address 171
BREAKER FAIL. 2) for an additional circuit breaker in the system. The information
applicable to the first applies here.
The disconnection of the measuring location (address 180 DISCON.MEAS.LOC) is a
help function for commissioning and revision works in the system.
The different methods of measured value monitoring (address 181 M.V. SUPERV)
are set out in detail in section 2.19.1. Voltages can of course also be monitored if the
device provides voltage inputs.
For trip circuit monitoring, under address 182 Trip Cir. Sup., a selection can be
made with regard to operation with two binary inputs (2 Binary Inputs) or only one
binary input (1 Binary Input). The inputs must be potential-free.
7UT613/63x Manual
C53000-G1176-C160-2