3. Resoluci´ on de modelos 30
3.3. Propiedades de materiales
3.3.1. Inconveniente en la zona de fusi´ on
3I
62BF 3U CBFP
REF 54_
I >0 3I> 67 3U> 59
I0
REA 101
df/dt 81O-R000
REF 54_
CBFP 62BF 50N
YNd transformer with earthing transformer on LV side
M M
Fig. 9
Fig. 9 ProteProtection, ction, controcontrol, mel, measuremasurement aent and sund supervisiopervision funn functions ctions of YNyof YNyn-connn-connected ected power power transftransform- orm-ers, implemented with RET 543 transformer terminals, REF 543 feeder terminals and REA 101 arc ers, implemented with RET 543 transformer terminals, REF 543 feeder terminals and REA 101 arc protection. The neutral point of the low-voltage network is earthed via a low resistance. The protection. The neutral point of the low-voltage network is earthed via a low resistance. The scheme is also applicable to other types of low-impedance earthed networks, where the neutral scheme is also applicable to other types of low-impedance earthed networks, where the neutral point is earthed effectively or via a low reactance. This sceme can be applied also for parallel point is earthed effectively or via a low reactance. This sceme can be applied also for parallel con-nected transformers.
nected transformers.
RET/3I
REF 54_
REF 54_
67 67 3I>
3I>
ff>> 8811OO pf pf f f
3I>
3I>
&
&
REA 101 REA 101 81O-R
RET 54_
RET 54_
3I
000 000000
TCS TCS R R 33II>> 5511
50
REF 54_
REF 54_
3I 3I II00
3U 3U 33UU<< 2277
59 59 3U>
3U> 000000
YNyn transformers impedance earthed LV neutral YNyn transformers impedance earthed LV neutral
M
Fig. 10
Fig. 10 ProtecProtection, contion, control, meatrol, measuremsurement and supent and supervisioervision function functions of an Yyn-conns of an Yyn-connectenected industrd industrial power ial power transformer, implemented with RET 543 transformer terminals, an REF 543 feeder terminal, an transformer, implemented with RET 543 transformer terminals, an REF 543 feeder terminal, an REX 521 protection relay and REA
REX 521 protection relay and REA 101 arc protection. The neutral point of the 101 arc protection. The neutral point of the low-voltage networklow-voltage network is earthed via a high resistance.
is earthed via a high resistance.
Yyn-trafo_highresEarthedLV
REF/3I, REA 101/3I REF/3I, REA 101/3I RET/3I (Basic) RET/3I (Basic)
R
RET/1U (Multi) RET/1U (Multi) RET/1I (Basic) RET/1I (Basic)
RET/3I (Multi) RET/3I (Multi) RET/4I (Basic) RET/4I (Basic)
R
RET 54_ (Basic) RET 54_ (Basic)
REF 54_
REF 54_
3I>
REX 521 H06 REX 521 H06
U
REA 101 REA 101
0
RET 54_ (Multi)
RET 54_ (Multi)U/f>
Fig. 11
Fig. 11 TransTransformeformer in block connr in block connection wiection with a generth a generator. Thator. The transfe transformer teormer terminal RErminal RET 543 is used foT 543 is used for r overall differential protection. An earthing resistor is
overall differential protection. An earthing resistor is recommended for the generator. The REX 521recommended for the generator. The REX 521 protection relay is used for abnormal voltage and frequency supervision and protection of the protection relay is used for abnormal voltage and frequency supervision and protection of the net-work and the machine.
work and the machine.
3~
RET 54_
RET 54_
87TN
REX 521 H06 REX 521 H06
CBCM
I(U)> 51V51V
3
REM 54_
REM 54_
C
Fig. 12 Transformer in block connection with a generator. The transformer terminal RET 543 is used for overall differential protection. An earthing resistor is recommended for the generator. Generator protection functions are divided for two REM 543 machine terminals (A and B). The current injec-tion device REK 510 is used in the rotor earth-fault protecinjec-tion scheme.
gen_blockconn-trafo2
3~
G
MF
REK 510
RET_/3I
RET_/1U RET_/1U RET_/1I
REM_/3I (A) REM_/3I (B)
REM_/2U(A)/3U(B) REM_/1U (A)
REM_/3I (A)
REM_/1I (A) RET_/3I
REM/I0R
(B) Q
P>
Q
3U> 59
CBFP
U/f> 24
E
CBFP 62BF f>/f< 81O
81U
RET 54_
87TN
Fig. 13 Symbol notations, part I 3I > 50/51
3I> 67
I0> 50N/51N
3U > 59 3U < 27
U0> 59N 3I2f > 68
CBFP 62BF
I2> 46
3DI > 87T
DI0> 87TN
SYMNOT1_RET
U< 27
3DI > 87TG
U/f 24
I(U)> 51V
I 0S> 64S
I0R> 64R
f >
df/dt 81U
81U-R f <
df/dt 81O
81O-R
f>/f< 81O 81U
3 49T
49
Q> 38
f > 81U
3 49G
= multiple-stage three-phase overcurrent protection, double low-set, high-set and instantaneous stages available (NOC3_)
= multiple-stage three-phase directional overcurrent protection, low-set, high-set and instantaneous stage available (DOC6_)
= multiple-stage earth-fault protection, low-set, high-set and instantaneous stage available (NEF1_)
= three-phase overvoltage protection, low-set and high-set stage available (OV3_)
= three-phase undervoltage protection, low-set and high-set stage available (UV3_)
= multiple-stage residual overvoltage protection, low-set, high-set and instantaneous stage available (ROV1_)
= inrush detection based on the 2nd harmonic content of phase currents, applied for preventing possible unnecessary operation of overcurrent or earth-fault protection during transformer switching-in or to start cold load pick-up logic (Inrush3_)
= negative phase sequence (NPS) protection, low-set and high-set stages available (NPS3_)
= underfrequency protection and frequency rate of change function (incl. in Freq1St_)
= three phase differential protection for transformers, stabilized and instantaneous stages (Diff3)
= restricted earth-fault (REF) protection, low- or high-impedance type (Diff3)
= circuit-breaker failure protection (included in all current-based short circuit and earth-fault protection function blocks)
= undervoltage protection, low-set and high-set stage available (UV3_)
= overall differential protection for generator and transformer blocks, stabilized and instantaneous stages (Diff6T)
= overexcitation protection, low-set and high-set stages available (OE1_)
= voltage-dependent overcurrent protection, low-set and high-set stages available (VOC6_)
= stator earth-fault protection (NEF1_)
= rotor earth-fault protection (NEF1_)
= overfrequency protection and frequency rate of change function (incl. in Freq1St_)
= over/underfrequency protection (incl. in Freq1St_)
= three-phase thermal overload protection for transformers (TOL3Dev)
= thermal supervision for generator windings and bearings with RTDs (MEAI_)
= overfrequency protection (incl. in Freq1St_)
= three-phase thermal overload protection for generator (TOL3Dev)
Fig. 14 Symbol notations, part II
SYMNOT2_RET
3I >
&
MCS
TCS
CBCM
Q P
3I
3U
I0 f
pf
U0
Z< 21G
3Z< 21
X< 40
P>
32F
60U 90V
U
= underimpedance protection for generator, low-set and high-set stages (UI6_)
= fuse failure supervision (FuseFail)
= underpower, low-forward power or reverse power protection, stages 1, 2 and 3 available (UPOW6St_)
= arc protection with REA 101
= measuring circuit supervision
= trip circuit supervision
= circuit-breaker condition monitoring
= automatic voltage regulation (COLTC)
= manual voltage regulation (COLTC)
= active power measurement, indication and supervision
= reactive power measurement, indication and supervision
= 3-phase current measurement, indication and supervision
= 3-phase voltage or phase-to-phase voltage measurement, indication and supervision
= frequency measurement, indication and supervision
= power factor measurement, indication and supervision
= residual current measurement, indication and supervision
= residual voltage measurement, indication and supervision
= three-phase underimpedance protection, low-set and high-set stages (UI6_)
= underexcitation protection, low-set and high-set stages (UE6_)
Fig. 15 Symbol notations, part III
E
R
000
000
0 I
SYMNOT3_RET
3I-harm 3U-harm
oT
oU
oT
WoT
TCoT
000