Thytronic NG10 User Manual

FUNCTION CHARACTERISTICS
63
NG10 - Manual - 04 - 2022
External fault stabilization by means of operating dual-slope percentage characteristic
The start of the first threshold of the differential protection on L1 phase (ST I
d
-L1) occurs when all the
following conditions are met:
• 87G-M-L Enable = ON
• I
dL1
≥ I
d
>
• I
dL1
≥ K1/100) ∙ I
SL1
• I
dL1
≥ K2/100) ∙ I
SL1
- Q
• 87H
-REST-L1
= OFF
• 87
SatDet-L1
= OFF
• BLK1 87 = OFF
where:
• 87G-M-L enable parameter for both the differential protection thresholds,
• I
d
> adjustment of the minimum threshold (or maximum sensitivity) of the differential protection,
• K1 adjustment as a percentage of the slope of the first segment of the operating characteristic of
differential protection,
• K2 adjustment as a percentage of the slope of the second segment of the operating characteristic
of differential protection,
• Q y-axis intercept of the line of the second segment of the operating characteristic of differential
protection,
• 87H
-REST-L1
logic state output of the the second and fifth harmonic restraint for phase L1,
• 87
SatDet-L1
logic state output of the CT’s saturation detector for phase L1,
• BLK1 87 logic state output of the logic block function of the differential protection 87G-M-L.
All differential elements can be enabled or disabled by setting ON or OFF the 87G-M-LEnable
parameter inside the Set \ Profile A(or B) \ Differential 87G-M-L \ Common configuration menu.
The I
d
>, K1, K2and Q parameters are available inside the Set \ Profile A(or B) \ Differential 87G-
M-L \ Id> Element \ definite time.
Similarly the start of the first threshold of the differential protection on L2 (ST I
d
>-L2) or L3 (ST I
d
>-L3)
phase occurs when all the following conditions are met:
• 87G-M-L Enable = ON
• I
dL2
≥ I
d
>
• I
dL2
≥ K1/100) ∙ I
SL2
• I
dL2
≥ K2/100) ∙ I
SL2
- Q
• 87H
-REST-L2
= OFF
• 87
SatDet-L2
= OFF
• BLK1 87 = OFF
• 87G-M-L Enable = ON
• I
dL3
≥ I
d
>
• I
dL3
≥ K3/100) ∙ I
SL3
• I
dL3
≥ K2/100) ∙ I
SL3
- Q
• 87H
-REST-L3
= OFF
• 87
SatDet-L3
= OFF
• BLK1 87 = OFF
where, 87
SatDet-L2
and 87
SatDet-L3
are the output state of the saturation detector for L2 and L3 phases.
The start of the first differential protection element (ST I
d
>) occurs at the instant of occurrence of
the threshold start in at least one of the L1, L2, L3 phases.
If the three conditions that led to the start of the first threshold of the differential protection on L1,
L2, L3 phases are maintained all for the duration of intentional delay t
d
>, when the time expires the
element trips.
The start of the second threshold of the differential protection on L1 phase (ST I
d
>>-L1) occurs when
all the following conditions are met:
• 87 Enable = ON
• I
dL1
≥ I
d
>>
• BLK1 87 = OFF
where I
d
>> is the setting threshold of the differential protection element.
Similarly the start of the second threshold of the differential protection on L2 (ST I
d
>>-L2) or L3
(ST I
d
>>-L3) phase occurs when all the following conditions are met:
• 87 Enable = ON
• I
dL2
≥ I
d
>>
• BLK1 87 = OFF
• 87 Enable = ON
• I
dL3
≥ I
d
>>
• BLK1 87 = OFF

Thytronic NG10 Specifications

General

Brand	Thytronic
Model	NG10
Category	Protection Device
Language	English