ABB REL650 series, Руководство по вводу в эксплуатацию, Страница: 180 / 208

The following will be shown if the load current flows in forward (exporting)
direction:
•
L1Dir = Forward
• L2Dir = Forward
• L3Dir = Forward
The following will be shown if the load current flows in the reverse direction
(importing):
•
L1Dir = Reverse
• L2Dir = Reverse
• L3Dir = Reverse
Compare this result with the information given by the external equipment, it
must be the same. If the direction of the three phases is not the same, this is a
sign of incorrect connection of the voltage or current transformers serving the
distance protection function. It is also possible that there is a wrong setting for
the earthing point for one or more of the CTs serving distance protection (the
setting name is:
CTStarPoint available under the HMI menu: Main menu/
Configuration/Analog modules ).
If the directional function shows forward when it should show reverse (or
vice-versa) for all the three phases, this probably means a wrong connection of
CTs and/or VTs serving the distance protection, or it can mean a wrong setting
of earthing point (the setting name is :
CTStarPoint ) for all the three CTs, or it
could mean a wrong setting for the pre-processing blocks
(
3PhaseAnalogGroup under the HMI menu: Main menu/Configuration/
Analog modules ) connected to the CTs/VTs and serving the distance
protection (verify that no wrong negation has been set; the setting name is:
Negation ).
If the directional function shows “No direction” for all the three phases it can
mean that the load current is below the minimum operating current or that the
load impedance has an angle which is outside the above given valid angles for
determining forward or reverse direction.
If the directional function shows “No direction” for only some of the three
phases, this probably means a wrong CTs/VTs connection.
4. The measured values are shown any time the load current is higher than 3% of
the base current:
•
L1R
• L1X
• L2R
• L2X
• L3R
• L3X
The measured impedance information can still be used to determine the
direction of the load. A positive resistance measured in all phases indicates a
forward (exporting) resistive load (active power), while a negative sign
indicates a reverse (importing) resistive load (active power). Usually it is
enough to look at the resistive values to get information of the load direction,
Section 10
1MRK 506 383-UEN A
Checking the directionality
174 Line distance protection REL650 2.2 IEC
Commissioning manual