Schweitzer Engineering Laboratories SEL-734W, Справочник по полевым условиям эксплуатации

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1.2
SEL-734W and SEL Wireless Current Sensor Field Reference Guide Date Code 20191029
Introduction and Specifications
System Features and Benefits
The SEL-734W processes data from one or three SEL-WCS devices and from the
CPT to implement a variety of cap bank control strategies. The SEL-734W uses
current measured independently from three SEL-WCS devices and one measured
voltage to provide three-phase switching decisions and monitoring. For this
application, the SEL-734W creates the other two voltage phases of equal magni-
tude to the measured phase, but at 120 and –120 degrees rotation relative to the
measured phase.
The SEL-734W continuously samples voltage on the power lines (via post-line
sensor or a single-phase CPT) and receives data from the SEL-WCS devices.
Combining the data from the SEL-WCS and the voltage measurements, the
SEL-734W accurately measures the phase angle between the system voltage and
the current. The SEL-734W uses both the measured voltage and the current
received from the SEL-WCS to calculate real and reactive power. The
SEL-734W computes other quantities such as power factor and total harmonic
distortion by using the received data from the SEL-WCS along with the mea-
sured voltage.
System Features and Benefits
The SEL-734W and SEL-WCS system measures voltage from a CPT (or line
post sensor) and currents to make switching decisions for a variety of advanced
control strategies such as VAR, current, and power factor. The SEL-WCS sends
data periodically to the SEL-734W. The SEL-734W uses the received data along
with measured voltage from the CPT to compute the quantities that allow the
SEL-734W to make switching decisions, provide metering information and
power quality information, and store events and load profiles. Additional control
strategies include voltage and time-of-day.
The SEL-734W and SEL-WCS system measures one voltage and three currents
from the SEL-WCS devices to provide three-phase switching decisions and mon-
itoring.
Figure 1.2 System Overview
Control Power
Transformer
A
B
C
N
Capacitor
Bank
Three-Phase
Capacitor Bank
Switch
SEL-734W
WCS_A
WCS_B
WCS_C