Schweitzer Engineering Laboratories SEL-787-2, Manual

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Schweitzer Engineering Laboratories, Inc. SEL-787-2, -3, -4 Data Sheet
15
Load Profile
The SEL-787 features a programmable Load Data Pro-
file (LDP) recorder that records as many as 17 metering
quantities into nonvolatile memory at fixed time inter-
vals. The LDP saves several days to several weeks of the
most recent data depending on the LDP settings
(9800 entries total).
Synchronized Phasor Measurement
Combine the SEL-787 with an SEL IRIG-B time source
to measure the system angle in real time with a timing
accuracy of ±10 µs. Measure instantaneous voltage and
current phase angles in real time to improve system oper-
ation with synchrophasor information. Replace state
measurement, study validation, or track system stability.
Use SEL-5077
SYNCHRO
WAV
E
®
Server Software or
SEL-5078-2
SYNCHRO
WAV
E
®
Central Visualization and
Analysis Software to view system angles at multiple
locations for precise system analysis and system-state
measurement (see
Figure 15 ).
Table 5 SEL-787 Metered Values (Model Dependent)
Types of Metering
Instantaneous RMS Remote Analogs Energy
Math Variables Synchrophasors Max/Min Thermal
Demand and Peak Demand Analog Inputs
Quantity Description
Currents I x W n
( x = A, B, C, n = 1, 2, 3, 4)
Winding phase current magnitude and angle, primary A
IN Neutral current magnitude and angle, primary A
IGW n ( n = 1, 2, 3, 4) Residual-ground fault current and angle per winding, primary A
3I2W n ( n = 1, 2, 3, 4) Negative-sequence current and angle per winding, primary A
IOP z ( z = 1, 2, 3) Differential operate current, scaled to TAP
IRT z ( z = 1, 2, 3) Differential restraint current, scaled to TAP
I n F2, I n F4, I n F5 ( n = 1, 2, 3, 4) Current harmonics, I n F2/IOP n (%) for 2nd, 4th, 5th harmonics
Voltages VA, VB, VC Phase voltages and angles, primary volts, for wye-connected potential transformers
Voltages VAB, VBC, VCA Phase-to-phase voltages and angles, primary volts, for delta-connected potential transformers
Voltage VG Residual-ground voltage and phase angle, primary volts, for wye-connected potential transformers
Voltage 3V2 Negative-sequence voltage and phase angle, primary volts
Power kVA, kW, kVAR Calculated apparent, real, and reactive power scaled to primary values (single and three-phase)
a
a
Single-phase power and power factor quantities are not available when delta-connected PTs are used.
Energy MWh, MVARh Three-phase positive and negative megawatt-hours, megavar-hours
Power Factor PF Single and three-phase power factor (leading or lagging)
a
Voltage VS Synchronism-check voltage channel, voltage magnitude and angle, primary volts
Voltage VDC Station battery voltage
Frequency FREQ Measured system frequency (Hz)
Frequency FREQS Measured frequency (Hz) of synchronism-check channel
V/Hz Calculated volts/hertz in percent, using highest measured voltage and frequency
AI x 01–AI x 04 ( x = 3, 4, or 5) Analog inputs
MV01–MV32 Math variables
RA001–RA128 Remote analogs
RTD1–RTD12 RTD temperature measurement (degrees C)