Siemens SIPROTEC 7UT613 series Manual page 98

2 Functions
Circuit Breaker
Status
98
the polarity of currents thus needs to be ensured by means of the polarity settings set
out in the section General System Data.
Apart from currents and voltages, protection and additional functions use the same
definition of current direction as a matter of principle. This applies to 7UT613/63x thus
also to reverse power protection, forward power monitoring, operational measured
values for power and work, and, if required, user-defined flexible protection functions.
When the device is delivered from the factory, its power and operating values are
defined in such manner that power in the direction of the protected object is consid-
ered positive: Active components and inductive reactive components in the direction
of the protected object are positive. The same applies to the power factor cos ϕ
It is occasionally desired to define the power draw of the protected object (e.g. as seen
from the busbar) as positive. The signs for these components can be inverted by using
parameter address 1107 P,Q sign.
Please ensure that the definition of signs conforms with the direction of the reverse
power protection and the forward power monitoring when using these power functions.
In case of a generator in accordance with figure "Power Measurement on a Generator"
(in section "Topology of the Protected Object", margin heading "Assignment of
Voltage Measuring Inputs") where the voltage measuring location U is assigned to the
current measuring location M1, the default setting not reversed is not inverted,
because the in-flowing current into the generator from the starpoint at M1 together with
the measured voltage at U results in positive power. However, if the voltage at U is as-
signed to the current measuring location M2, P,Q sign = reversed must be set,
because the current flowing out of the generator withU is supposed to be positive
power.
In order to function optimally, several protection and supplementary functions require
information regarding the state of the circuit breaker. Command processing makes
also use of the feedback information from the switching devices.
If, for instance, the circuit breaker failure protection is used to monitor the reaction of
a specific circuit breaker by evaluating the current flow, the protection device must
know the measuring location at which the current through the breaker is acquired.
In addition to such circuit breaker information, as may be available from the feedback
indications provided by the circuit breaker auxiliary contacts, the device evaluates the
electrical criteria that determine that a circuit breaker cannot be open if a current is
flowing through it. This current criterion is defined by a pre-determined current value
I-REST, below which an open breaker is detected.
As the topologies encountered in a system can be quite complex, the circuit breaker
can be assigned to a measuring location or to a side.
In 3-phase protected objects a residual current for each of the up to 5 possible sides
of the main protected object can be set and for each of the up to 5 possible measuring
locations. In this device, the options are of course restricted to the sides and measur-
ing locations that actually exist and have been specified by the topology. The
maximum range of possible addresses includes:
Address 1111 PoleOpenCurr.S1 for side 1 of the main protected object,
Address 1112 PoleOpenCurr.S2 for side 2 of the main protected object,
Address 1113 PoleOpenCurr.S3 for side 3 of the main protected object,
Address 1114 PoleOpenCurr.S4 for side 4 of the main protected object,
Address 1115 PoleOpenCurr.S5 for side 5 of the main protected object.
7UT613/63x Manual
C53000-G1176-C160-2