FUNCTION CHARACTERISTICS
87
NA30 - Manual - 04 - 2022
AND
The residual voltage (
U
E
) fundamental component overcomes the threshold (
U
ED>
,
U
ED>>
,
U
ED>>>
,
U
ED>>>>
).
B) The residual current phasor (
I
E
) is located inside the angular sector defined by own characteristic
angle (
β
E
>,
β
E
>>,
β
E
>>>,
β
E
>>>>) and half operating sector (
Θ
E
>,
Θ
E
>>,
Θ
E
>>>,
Θ
E
>>>>), that is the
-
β
E
≤ (
Θ
E
-
Φ
E
) ≤ +
β
E
condition is fulfilled.
If the operation mode is switched to “not directional” (by the 74VT function), the start of any 67N
threshold becomes active when the following is complied:
- The residual current (
I
E
) fundamental component overcomes the threshold (
I
ED>
,
I
ED>>
,
I
ED>>>
,
I
ED>>>>
)
The operating mode (
Mode67N
), the residual voltage measurement type (
Type67N
), the insensi-
bility zone enabling (I
nsens-Zone
), the threshold multiplier for the insensibility zone (
M
) and the
operation from 74VT (
74VText67N
) may be selected by setting the concerning parameters, located
inside the
Set \ Profile A(or B) \ Directional earth fault overcurrent-67N \
Common configuration
menu.
The settable operating mode is
I
(module) or
I*cos
(projection).
Projection
If the
projection
principle and he operation mode is not switched to “not directional” (by the 74VT
function), the start of any 67N threshold becomes active when the following C) condition is active:
C) in the “Insens-Zone=OFF” operating mode:
- Residual current projection on the characteristic axis
I
E
∙cos(
Φ
E
-
Θ
E
) > 0
AND
- The residual current projection on the characteristic axis
I
E
∙cos(
Φ
E
-
Θ
E
) overcomes the threshold
(
I
ED>
,
I
ED>>
,
I
ED>>>
,
I
ED>>>>
)
AND
- The residual voltage (
U
E
) fundamental component overcomes the threshold (
U
ED>
,
U
ED>>
,
U
ED>>>
,
U
ED>>>>
).
AND
The residual current phasor (
I
E
) is located inside the angular sector defined by own characteristic
angle (
β
E
>,
β
E
>>,
β
E
>>>,
β
E
>>>>) and half operating sector (
Θ
E
>,
Θ
E
>>,
Θ
E
>>>,
Θ
E
>>>>), that is the
-
β
E
≤ (
Θ
E
-
Φ
E
) ≤ +
β
E
condition is fulfilled.
[1]
While in the “Insens-Zone=ON” operating mode:
- Residual current projection on the characteristic axis
I
E
∙cos(
Φ
E
-
Θ
E
) > 0
AND
- The residual current projection on the characteristic axis
I
E
∙cos(
Φ
E
-
Θ
E
) overcomes the threshold
(
I
ED>
,
I
ED>>
,
I
ED>>>
,
I
ED>>>>
)
AND
- The residual voltage (
U
E
) fundamental component overcomes the threshold (M∙
U
ED>
, M∙
U
ED>>
,
M∙
U
ED>>>
, M∙
U
ED>>>>
)
OR
The residual current projection on the characteristic axis
I
E
∙cos(
Φ
E
-
Θ
E
) overcomes the threshold
(M∙
I
ED>
, M∙
I
ED>>
,
M∙
I
ED>>>
, M∙
I
ED>>>>
)
AND
- The residual voltage (
U
E
or
U
EC
) fundamental component overcomes the threshold (
U
ED>
,
U
ED>>
,
U
ED>>>
,
U
ED>>>>
).
AND
The residual current phasor (
I
E
) is located inside the angular sector defined by own characteristic
angle (
β
E
>,
β
E
>>,
β
E
>>>,
β
E
>>>>) and half operating sector (
Θ
E
>,
Θ
E
>>,
Θ
E
>>>,
Θ
E
>>>>), that is the
-
β
E
≤ (
Θ
E
-
Φ
E
) ≤ +
β
E
condition is fulfilled.
[2]
If the operation mode is switched to “not directional” (by the 74VT function), the start of any 67N
threshold becomes active when the following is complied:
- The residual current (
I
E
) fundamental component overcomes the threshold (
I
ED>
,
I
ED>>
,
I
ED>>>
,
I
ED>>>>
)
For both the operating mode (module or projection), when the start signal goes ON a concerning
counter starts; after expiry of the associated operate time (
t
ED>
,
t
ED>>
,
t
ED>>>
,
t
ED>>>>
) a trip command
is issued, if instead the above conditions don’t remain valid, the element it is restored.
All the parameters are located inside the menus concerning the four elements, separately for defi-
nite and inverse time characteristics.
Example: the operate time concerning the first threshold with definite time characteristic (
IED>def
)
is available inside the
Set \ Profile A(or B) \ Directional earth fault overcurrent-67N \
IED> Element
\ Definite time
menu.
Note 1 For each threshold the projection of the residual current phasor on the characteristic axis is: I
E
cos(
Θ
E
>-
Φ
E
), I
E
cos(
Θ
E
>>-
Φ
E
), I
E
cos(
Θ
E
>>>-
Φ
E
),
I
E
cos(
Θ
E
>>>>-
Φ
E
) when “direct” residual voltage is selected (U
E
), or
I
E
cos(
Θ
E
>-
Φ
EC
), I
E
cos(
Θ
E
>>-
Φ
EC
), I
E
cos(
Θ
E
>>>-
Φ
EC
), I
E
cos(
Θ
E
>>>>-
Φ
EC
) when “calculated” residual voltage is selected (U
EC
).
The
Θ
E
,
β
E
and
Φ
EC
symbols are not used inside the ThyVisor and MMI menus.
Note 2 For each threshold the projection of the residual current phasor on the characteristic axis is: I
E
cos(
Θ
E
>-
Φ
E
), I
E
cos(
Θ
E
>>-
Φ
E
), I
E
cos(
Θ
E
>>>-
Φ
E
),
I
E
cos(
Θ
E
>>>>-
Φ
E
) when “direct” residual voltage is selected (U
E
), or
I
E
cos(
Θ
E
>-
Φ
EC
), I
E
cos(
Θ
E
>>-
Φ
EC
), I
E
cos(
Θ
E
>>>-
Φ
EC
), I
E
cos(
Θ
E
>>>>-
Φ
EC
) when “calculated” residual voltage is selected (U
EC
).
The
Θ
E
,
β
E
and
Φ
EC
symbols are not used inside the ThyVisor and MMI menus.
