ABB RELION 620 Series Technical Manual page 672

Section 4
Protection functions
4.5.7
4.5.7.1
4.5.7.2
4.5.7.3
4.5.7.4
666
Positive-sequence undervoltage protection PSPTUV
Identification
Function description
Positive-sequence undervoltage
protection
Function block
GUID-24EBDE8B-E1FE-47B0-878B-EBEC13A27CAC V1 EN
Figure 337: Function block
Functionality
The positive-sequence undervoltage protection function PSPTUV is used to detect
positive-sequence undervoltage conditions. PSPTUV is used for the protection of
small power generation plants. The function helps in isolating an embedded plant
from a fault line when the fault current fed by the plant is too low to start an overcurrent
function but high enough to maintain the arc. Fast isolation of all the fault current
sources is necessary for a successful autoreclosure from the network-end circuit
breaker.
The function starts when the positive-sequence voltage drops below the set limit.
PSPTUV operates with the definite time (DT) characteristics.
The function contains a blocking functionality. It is possible to block function outputs,
the definite timer or the function itself, if desired.
Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
The operation of PSPTUV can be described using a module diagram. All the modules
in the diagram are explained in the next sections.
IEC 61850 IEC 60617
identification identification
PSPTUV U1<
1MRS757644 F
ANSI/IEEE C37.2
device number
47U+
620 series
Technical Manual