4.4.3.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE
C37.2 device
number
Residual overvoltage protection ROVPTOV Uo> 59G
4.4.3.2 Function block
Figure 215: Function block
4.4.3.3 Functionality
The residual overvoltage protection function ROVPTOV is used in distribution
networks where the residual overvoltage can reach non-acceptable levels in, for
example, high impedance earthing.
The function starts when the residual voltage exceeds the set limit. ROVPTOV
operates with the definite time (DT) characteristic.
The function contains a blocking functionality. It is possible to block function
outputs, the definite timer or the function itself, if desired.
4.4.3.4 Operation principle
The function can be enabled and disabled with the
Operation
setting. The
corresponding parameter values are "On" and "Off".
The operation of ROVPTOV can be described by using a module diagram. All the
modules in the diagram are explained in the next sections.
Figure 216: Functional module diagram
Level detector
The residual voltage is compared to the set
Start value
. If the value exceeds
the set
Start value
, the level detector sends an enable signal to the timer. The
residual voltage can be selected with the
Uo signal Sel
setting. The options are
"Measured Uo" and "Calculated Uo". If "Measured Uo" is selected, the voltage ratio
for Uo-channel is given in the global setting Configuration> Analog inputs>
Voltage (Uo,VT). If "Calculated Uo" is selected, the voltage ratio is obtained from
Protection functions
1MRS758755 C
436 REC615 & RER615
Technical Manual
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