Thytronic XMR-V 4V User Manual

320
FUNCTION CHARACTERISTICS
enabled for transmit a selective block from/to other internal protective elements.
[1]
With single enable flag for first or second threshold of differential protection the element can pro-
duce the output block (committed pilot wire or output relay) programmed for logic selectivity of side
H and/or side L if the 87T-BLK1parameter is set to ON inside the Set \ Profile A(or B) \ Differential
87G-87M-87T \ Common configuration menu.
Stabilization on powering and excitation of the power transformer with second and fifth harmonic restraint
With Transformer (Transf) selection the second and fifth harmonic restraint is enabled: the ProtObj
parameter is available inside the Set \ Base menu.
If Motor or Generator (
GEN-MOT-LINE-BAR) is selected the second and fifth harmonic is auto-
matically excluded.
[2]
The second harmonic restraint of differential protection allows you to block unwanted operation at
powering of the transformer.
The fifth harmonic restraint of differential protection allows you to block unwanted operation at du-
ring the operation of the transformer in over-excitation state.
The relay calculates:
A) RMS value of the second harmonic component of differential currents:
I
d2L1
=DFT2[I
dL1
]
I
d2L2
=DFT2[I
dL2
]
I
d2L3
=DFT2[I
dL3
]
where DFT2[x] is the calculated rms value of the second harmonic component of differential cur-
rents concerning the x variable obtained by Discrete Fourier Transform (DFT).
B) RMS value of the fifth harmonic component of differential currents:
I
d5L1
=DFT5[I
dL1
]
I
d5L2
=DFT5[I
dL2
]
I
d5L3
=DFT5[I
dL3
]
where DFT5[x] is the calculated rms value of the fifth harmonic component of differential currents
concerning the x variable obtained by Discrete Fourier Transform (DFT).
C) Second harmonic component / fundamental component ratio of differential currents:
I
d2L1
/ I
dL1
I
d2L2
/ I
dL2
I
d2L3
/ I
dL3
D) Fifth harmonic component / fundamental component ratio of differential currents:
I
d5L1
/ I
dL1
I
d5L2
/ I
dL2
I
d5L3
/ I
dL3
If at least one ratio I
d2L1
/ I
dL1
, I
d2L2
/ I
dL2
, I
d2L3
/ I
dL3
exceeds the second harmonic restraint setting
2nd-REST> the start of the second harmonic restraint in the corresponding phase goes ON (ST 2nd-
REST-L1 or ST 2nd-REST-L2 or ST 2nd-REST-L3).
If at least one ratio I
d5L1
/ I
dL1
, I
d5L2
/ I
dL2
, I
d5L3
/ I
dL3
exceeds the fifth harmonic restraint setting
5th-REST> the start of the second harmonic restraint in the corresponding phase goes ON (ST 5th-
REST-L1 or ST 5th-REST-L2 or ST 5th-REST-L3).
An intentional reset time delay t
HREST-RES
, common for second-fifth harmonic restraint (with zero
adjustment the second and fifth harmonic restraint is restored at the moment when the relationship
between the effective values of the second or fifth harmonic and fundamental component of diffe-
rential current falls below the threshold setting 2
nd-REST
> or 5
th-REST
>).
The threshold setting
2ndh-REST>and reset time delay setting t
HREST-RES
are available inside the
Set \ Profile A(or B) \ Differential 87G-87M-87T \ Harmonic restraint menu.
The start of the element can control an output relay by programming the ST2nd-REST-K and/or
ST5th-REST-Kparameter available inside the menu Set \ Profile A(or B) \ Differential 87G-87M-87T
\ Harmonic restraint menu, similarly for LED (
ST2nd-REST-Land/or ST5th-REST-L).
The start of the second harmonic restraint threshold at one phase or the fifth harmonic restraint thre-
shold at the same phase determines the starting of the harmonic restraint element (ST REST-H-L1, L2
REST-H-ST , ST H-REST-L3) for that phase.
The start of the second harmonic restraint threshold (ST 2nd-REST>) occurs at the instant of occur-
rence of the start of threshold in at least one of the L1, L2, L3 phases.
The start of the fifth harmonic restraint threshold (ST 5th-REST>) occurs at the instant of occurrence
of the start of threshold in at least one of the L1, L2, L3 phases.
The start of the harmonics harmonic restraint is produced from start of the second or fifth harmonic
restraint threshold (ST 2nd-REST>or ST 5th-REST>).
Nota 1 The exhaustive treatment of the internal selective block (Block 4) function may be found in the “Internal selective block” paragraph inside
CONTROL AND MONITORING section.
Note 2 Regardless of the value set all parameters in the Set \ Profile A(or B) \ Differential 87G-87M-87T \ Harmonic restraint menu are not significant
XMR-D EQUIPMENT MANUAL
Ed. 2.9 - 02/2021

Thytronic XMR-V 4V Specifications

General

Brand	Thytronic
Model	XMR-V 4V
Category	Protection Device
Language	English