GE Entellisys 4.0, Application Manual

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37 37
Section 7. Protection Section 7. Protection
2. 2. Enable o Enable or di r disable sable for TRIP for TRIP or or OPEN OPEN to to enable enable
or disable the protection action selected in or disable the protection action selected in
setting 1 for each pick or delay combination.
setting 1 for each pick or delay combination.
3. 3. Pickup Pickup 1 1 for TRIP for TRIP or or OPEN OPEN sets sets the thr the threshold eshold
for the first target circuit breakers. for the first target circuit breakers.
4. 4. Delay Delay 1 for 1 for TRIP or TRIP or OPEN OPEN sets sets the time the time delay delay
for the first target circuit breakers. for the first target circuit breakers.
5. 5. Pickup Pickup 2 2 for TRIP for TRIP or or OPEN OPEN sets sets the thr the threshold eshold
for the second target circuit breakers. for the second target circuit breakers.
6. 6. Delay Delay 2 for 2 for TRIP or TRIP or OPEN OPEN sets sets the time the time delay delay
for the second target circuit breakers. for the second target circuit breakers.
7. 7. Backup Backup function function enabled enabled or or disabled disabled for for TRIP TRIP
or OPEN for the second group of target circuit or OPEN for the second group of target circuit
breakers for backup of the first group.
breakers for backup of the first group.
8. 8. Backup Backup time time delta delta enabled enabled or or disabled disabled for for TRIP TRIP
or OPEN for an additional time delay before the or OPEN for an additional time delay before the
backup group of circuit breakers is operated if
backup group of circuit breakers is operated if
the fault current continues.
the fault current continues.
9. 9. Enable Enable or di or disable sable for al for alarm onl arm only is y is a gl a global obal
command to enable or disable alarm settings. command to enable or disable alarm settings.
10. 10. Pick Pickup 1 f up 1 for al or alarm o arm only. nly.
11. 11. Delay Delay 1 fo 1 for al r alarm o arm only. nly.
12. 12. Pick Pickup 2 f up 2 for al or alarm o arm only. nly.
13. 13. Delay Delay 2 fo 2 for al r alarm o arm only. nly.
The available The available delay settings are delay settings are the same as the same as for the for the
short-time and ground-fault bands. The minimum short-time and ground-fault bands. The minimum
current pickup setting is 20% of the largest sensors
current pickup setting is 20% of the largest sensors
in the zone and the highest setting is 22,000 amperes.
in the zone and the highest setting is 22,000 amperes.
Calculations for the 87B algorithm Calculations for the 87B algorithm
The Entellisys calculation algorithms operate on the The Entellisys calculation algorithms operate on the
raw digitized data obtained from the current sensors.
raw digitized data obtained from the current sensors.
Because of this, the mathematical operations are
Because of this, the mathematical operations are
performed on a single sample of data from each
performed on a single sample of data from each
current used in the calculation. Since the current
current used in the calculation. Since the current
data across
data across the system the system are are 100% synchronized, 100% synchronized,
the calculations need not take into account the the calculations need not take into account the
phase angle between voltage and current, and
phase angle between voltage and current, and
may be, strictly based, on the instantaneous
may be, strictly based, on the instantaneous
current magnitudes.
current magnitudes.
During each half-power cycle the CPU calculates During each half-power cycle the CPU calculates
the mean-squared residual current for each phase
the mean-squared residual current for each phase
of the M circuit breakers in the zone. An example
of the M circuit breakers in the zone. An example
of the formula for phase A is:
of the formula for phase A is:
ΙΙ
2 2
residual,A residual,A
= =
2 2
Σ Σ (( ii
A,0,k A,0,k
± ± ii
A,1,k A,1,k
±…±i ±…±i
A,M-1,k A,M-1,k
))
2 2
where where
ΙΙ
residual,A residual,A
is the residual current for phase A, is the residual current for phase A,
N N
is the number of samples per half-cycle (64), is the number of samples per half-cycle (64),
M M
is is
the number of circuit breakers in the zone carrying the number of circuit breakers in the zone carrying
current in or out, and i
current in or out, and i
A,0,k A,0,k
…i …i
A,M-1,k A,M-1,k
are the are the
kk
th samples th samples
of phase A circuit breakers 0 through of phase A circuit breakers 0 through
M M
–1. The –1. The
same calculation is performed by the CPU for all same calculation is performed by the CPU for all
three phases simultaneously and adjustments for
three phases simultaneously and adjustments for
CT errors are performed for each phase and CT.
CT errors are performed for each phase and CT.
The total residual current for the three-phase system The total residual current for the three-phase system
is calculated by selecting the maximum single-phase
is calculated by selecting the maximum single-phase
residual of the three residual currents. The subscript
residual of the three residual currents. The subscript
adjusted adjusted
indicates that the residual currents have indicates that the residual currents have
been adjusted for CT error: been adjusted for CT error:
ΙΙ
2 2
BD BD
= = m ma axx ((
ΙΙ
2 2
residual,A,adjusted, residual,A,adjusted,
ΙΙ
2 2
residual,B,adjusted, residual,B,adjusted,
ΙΙ
2 2
residual,C,adjusted residual,C,adjusted
))
If the thresholds for time and magnitude are If the thresholds for time and magnitude are
exceeded, a command to sound alarm 1, sound
exceeded, a command to sound alarm 1, sound
alarm
alarm 2 if it 2 if it is set, is set, trip th trip the prima e primary ry targe targets, and ts, and
eventually trip the secondary targets is issued by eventually trip the secondary targets is issued by
the CPU,
the CPU, as reques as requested by the user settings ted by the user settings..
Each residual current is provided with a cooling Each residual current is provided with a cooling
algorithm to allow for the thermal characteristics of
algorithm to allow for the thermal characteristics of
the buses and integrate intermittent faults over time.
the buses and integrate intermittent faults over time.
Table 7.12 Table 7.12
Available Relay Function Settings Available Relay Function Settings
1 1
The undervoltage relay has the capability for a fixed or inverse time delay. The accuracy of the inverse time delay is ±4%. The undervoltage relay has the capability for a fixed or inverse time delay. The accuracy of the inverse time delay is ±4%.
2 2 Pickup may occur at no more Pickup may occur at no more than 10 Hz below the nominal system frequency and never below 45 Hz. The setting range on 5 than 10 Hz below the nominal system frequency and never below 45 Hz. The setting range on 5 0 Hz systems is 45–50 Hz. 0 Hz systems is 45–50 Hz.
3 3 Pickup may occur at no mor Pickup may occur at no moree than 10 Hz above than 10 Hz above the nominal system frequency, which is 70 Hz the nominal system frequency, which is 70 Hz for 60 Hz systems and 60 Hz for 60 Hz systems and 60 Hz for 50 Hz systems. for 50 Hz systems.
4 4
LTPU = long-time pickup setting. This relay is for alarm use only. LTPU = long-time pickup setting. This relay is for alarm use only.
C Ca ap pa ab biilliitty y O Ovve errvvo olltta ag ge e U Un nd de errvvo olltta ag ge e U Un nd de errffrre eq qu ue en nccy y O Ovve errffrre eq qu ue en nccy y P Ph ha asse e LLo ossss P Po ow we er R r Re evve errssa all H Hiig gh C h Cu urrrre en ntt S Sy yn ncch C h Ch he ecckk
A Alla arrm m YYeess YYeess YYeess YYeess YYeess YYeess YYeess YYeess
TTrriip p//O Op peen n YYeess YYeess YYeess YYeess YYeess YYeess N No o YYeess
P Piicckku up p 1 10 05 5––1 12 25 5% % 1 1% % 5 50 0––9 95 5% % 5 50 0––6 60 0 H Hzz, , 0 0..1 1 H Hzz
2 2
50–70 H, 0.1 Hz 50–70 H, 0.1 Hz
3 3
8- 8-50 50%, %, 1% 1% 10 10–9 –990 90 kW kW 10 10 kW kW 50 50–2 –200 00% L % LTP TPU 5 U 5% %
4 4
0–90 V 0–90 V,, 0.5 V 0.5 V,, 02 Hz, 02 Hz,
0.1 Hz, 0–60 D, 1D 0.1 Hz, 0–60 D, 1D
A Accccu urra accy y ± ±2 2% % ± ±2 2% % ± ±0 0..1 1 H Hzz ± ±0 0..1 1 H Hzz ± ±2 2% % ± ±2 2% % ± ±1 10 0% % ± ±2 2% %
TTim ime d e del elay ay 0. 0.5– 5–60 600 0 s, s, 0. 0.5 5 ss 0. 0.5– 5–60 600 s 0 s, 0 , 0.5 .5 ss 1 1 0 0..5 5––6 60 00 0 ss, , 0 0..5 5 ss 0 0..5 5––6 60 00 0 ss, , 0 0..5 5 ss 0 0..5 5––6 60 00 0 ss, , 0 0..5 5 ss 0 0..5 5––6 60 00 0 ss, , 0 0..5 5 ss 1 1––1 15 5 ss, , 1 1 ss N N//A A
A Accccu urra accy y ± ±0 0..1 1 ss ± ±0 0..1 1 ss 1 1 ± ±0 0..1 1 ss ± ±0 0..1 1 ss ± ±0 0..1 1 ss ± ±0 0..5 5 ss ± ±1 1 ss N N//A A
D Drro op p o ou utt 9 97 7% % TTh hrreessh ho olld d 1 10 03 3% % TTh hrreessh ho olld d 1 10 03 3% % TTh hrreessh ho olld d 9 97 7% % TTh hrreessh ho olld d 9 97 7% % TTh hrreessh ho olld d 9 97 7% % FFrreeq qu ueen nccy y 9 97 7% % TTh hrreessh ho olld d N No on nee
B Bllo occkkiin ng g V Vo olltta ag gee N No on nee 5 5––7 75 5% % 5 5% % 5 5% % 5 5% % N No on nee N No on nee D Deea ad d B Bu uss
FFlleex x llo og giic c cco on nttrro oll YYeess YYeess YYeess YYeess YYeess YYeess YYeess YYeess
Ν Ν
k= k=0 0
N/2-1 N/2-1