Download 256 Directional Power Relay www.GEindustrial.com/pm Simplify the

MIW Directional Power/Loss of Field
Once the magnitude of the three-phase
total power in the forward direction
(positive MW) falls below the pickup
level for the specified period of time an
alarm will occur.
10
The level is programmed in per unit of
generator MW calculated from the
rated MVA and rated power factor.
The low forward power element is
active only when the generator is online
and will be blocked until the generator
is brought online, for a period of time
defined by the setpoint. The pickup level
should be set lower than expected
generator loading during normal operations. If the fuse failure function is
operated the 32LF unit will be disabled.
Fuse Failure (60)
The MIW includes a VT fuse failure
unit. The unit checks the presence of
negative sequence voltage against
positive sequence voltage and the
current value.
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256
Directional Power Relay
Z1oe
Metering
z2
MIW provides metering values for
phase and ground currents. The accuracy is 3% in the complete range.
741752A1.ai
VAB
IA - IB = M1oe<Ø1oe
The formula: Z1oe =
where:
Z1oe =
Configurable Logic
Secondary phase to phase loss of
excitation impedance
M1oe<Ø1oe = Secondary impedance phasor
(magnitude and angle)
All relay quantities are in terms of secondary
impedances. The formula to convert primary
impedance quantities to secondary impedance
quantities is provided below.
Up to a maximum of 4 configurable
logic schemes can be implemented
into the MIW by means of using a set
of 4 pre-configured logic gates and
timer cells. A graphical user interface is
provided for configuration of MIW
logic. The outputs of the MIW configurable logic can be used to configure
digital outputs and LEDs.
Zpri X CTratio
VTratio
primary ohms impedance
programmed CT ratio, if CT ratio is
1200:5 use a value of 1200/5 = 240
programmed VT ratio, if VT ratio is
100:1 use a value of 100
where:
Zsec
Zpri =
CTratio =
VTratio =
=
WIRING
OPEN DELTA VT CONNECTION
PHASE A
CT
A
B
A
C
B
SINGLE PHASE VT CONNECTION
NOTE: 14 AWG wiring
recommended
AC
or
DC
C
A
B
C
B1 B2 B3 B4 A3 A4
B1 B2 B3 B4 A3 A4
C1 C2
A1
A2
B1 B2 B3 B4 A3 A4
VA N VB N VC N
VA N VB N VC N
IA N
+/L
-/N
VA N VB N VC N
VOLTAGE INPUTS
VOLTAGE INPUTS
POWER
Loss of Excitation (40)
The MIW detects loss of excitation by
using an impedance element on wye
connected generators. When the
impedance falls within the impedance
circle for the delay time specified a trip
will occur if it is enabled. The user can
enable circle#1 and/or circle#2 to tune
their protection feature to their system.
The larger circle diameter should be
set to the synchronous reactance of the
generator, xd and the circle offset
should be set to the generator transient
reactance x’d/2. This element will be
blocked if there is a fuse failure condition or if the generator is offline.
Offset
z1
Diameter
52a
TRIP COIL CONTROL
POWER +
<<
52a
TRIP
COIL
GE Power Management
>>
A5
A6
CAUTION: Fork or ring terminals must be used on the
termainal block.
NOTE: Suitable disconnect devices (switch or circuit
breaker) recommended located near the relay.
OVERVOLTAGE CATEGORY: II
B5
B6
MIW
Internally fused
1A/250V fast blow
Directional Power &
Loss of Field Relay
A8 CC1
A9 CC2
A10 COM
RS232
SAFETY
GND GROUND
GROUND
BUS
CURRENT
INPUT
VOLTAGE INPUTS
SDA B12(*)
A
SDB A12(*)
B
GND B11(*)
GROUND
JX
COM OUT4 OUT3 OUT1/2 OUT1
Directional Low Forward Power
(32LF)
M1oe
RS485
If the generator is accelerated from the
power system rather than the prime
mover, the reverse power element may
be blocked from start for a selectable
period of time.
Ø1oe
DIGITAL OUTPUTS(**)
The level is programmed in per unit of
generator MW calculated from the
rated MVA and rated power factor.
DIGITAL
INTPUTS(**)
Once the magnitude of the three-phase
total power exceeds the pickup level in the
reverse direction (negative MW) for the
specified period of time a trip will occur.
jx
Two configurable inputs are provided
for breaker status and block the loss of
field. Four configurable outputs are
provided for the operation of the 32RP,
32LP, 40 and 47 units.
TRIP
Directional Reverse Power (32RP)
Inputs and Outputs
READY
PROTECTION
B7
B8
INPUT
PROGRAMMABLE
CONTROLLER
B9
B10
A7
INPUT
741750A1.ai
ORDERING
To order select the basic model and the desired features from the Selection Guide below.
MIW1 0 * 0 E 2 0 0 * 0 0 *
1
5
F
H
Phase CT In = 1A (0.1 - 2.4 A)
Phase CT In = 5A (0.5 - 12 A)
24-48 VDC (Range: 19 ~ 58 Vdc) Power Supply
110-250 VDC (Range: 88 ~ 300 Vdc) Power Supply
120-230 VAC (Range: 88 ~ 264 Vac) Power Supply
C Individual relay
S Mounted in an M+ system†
Accessories
DEPTH REDUCING COLLAR:
Reduces the mounting depth in 63 mm.
†If relays are to be mounted in an M+ system either an M050 half 19" rack or M100 full 19"
rack case must be ordered. The M050 and M100 racks are provided at no additional cost.
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