Section 13
Checking the directionality
13.1
Overview
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Before starting this process, all individual devices that are involved in the fault clearance
process of the protected object must have been individually tested and must be set in
operation. The circuit breaker must be ready for an open-close-open cycle.
The directional test is performed when the protected object is energized and a certain amount
of load current is available. It is also necessary to know the flow of the load current (import or
export, i.e. forward or reverse) by help of the indication from an external instrument (energy-
meter, or SCADA information).
The design of the test procedure depends on the type of protection function to be tested.
Some items that can be used as guidelines are the following.
13.2
Testing the directionality of the distance protection
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The test is performed by looking at the information given by the High speed distance
protection ZMFPDIS, ZMFCPDIS or the directional function ZDRDIR or ZDMRDIR whichever is
used.
Procedure:
1.
Make sure that all control and protection functions that belong to the object that are
going to be energized have been tested and are set to be in operation
2.
Make sure that the primary load current fulfills the following conditions (by using an
external equipment):
•
The magnitude of the primary load current must be higher than the minimum
operating current set for the directional elements in the IED. In case of default
settings this means:
•
load current > 5% of base current
•
Otherwise the settings
IMinOpPE and IMinOpPP for ZDRDIR or ZDMRDIR are
available under the HMI menu: Main menu/Settings/IED Settings/
Impedance protection/DirectionalImpedance
The primary load impedance must have an angle (PHI) between the setting angles for the
directional lines. In case of default settings this means:
•
for forward (exported) load: -15 deg < PHI < 115 deg
•
for reverse (imported) load: 165 deg < PHI < 295 deg
The settings for forward load: -
ArgDir < PHI < ArgNegRes and the settings for reverse
load: 180 deg -
ArgDir < PHI < 180 deg + ArgNegRes included in the directional functions
ZDRDIR or ZDMRDIR are available under the HMI menu:
•
Main menu/Settings/IED Settings/Impedance protection/DirectionalImpedance
3.
The directionality of the load current is shown by the High speed distance protection
ZMFPDIS or ZMFCPDIS under the HMI menu: Main menu/Test/Function status/
Impedance protection/HighSpeedDistance or by the directional function ZDRDIR or
ZDMRDIR and it is available under the HMI menu: Main menu/Test/Function status/
Impedance protection/DirectionalImpedance
The following will be shown if the load current flows in forward (exporting) direction:
1MRK 502 067-UEN B
Section 13
Checking the directionality
233
Commissioning manual
