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4.8.10 Resistance, Reactance, Impedance (1-Cycle Update)
These measurements are calculated for each phase from the fundamental values of
voltage and current. The Impedance value, combined with the voltage-to-current phase
angle, gives the polar form of the impedance. The Resistance and Reactance represent
the rectangular form of the Impedance.
4.8.11 Slip Frequency (1-Cycle Update)
The Slip Frequency is the difference in the Frequency of a phase of Bus 1 Voltage to Bus
2 Voltage. Values are + when Bus 1 Frequency is greater.
4.8.12 Individual Phase Harmonic Magnitudes and Phase Angles (1-Cycle Update)
The M87x measures individual Harmonic Magnitudes and Harmonic Phase Angles for all
Currents, Line-to-Neutral Voltages, and Line-to-Line Voltages.
reported in units of Amperes or Volts, not in percent. The Harmonic Phase Angles are in
degrees, and all are referenced to the Bus 1 V
Phase Angles in a common reference system. Values are from -180 to +180 Degrees.
4.9 Temperature (1-Second Update)
The M87x measures the internal temperature of the unit using a sensor located on the A10
Analog-Digital Signal processor Board. Values are reported in increments of 0.5C.
4.10 Symmetrical Components (1-Cycle Update)
For each three phase input, Voltage and Current, the M87x generates the positive-
sequence, negative-sequence, and zero-sequence vectors relative to phase A. These
vectors represent the symmetrical components of their respective busses. The sequence
component vectors are calculated by applying the vector operator a to the fundamental
vectors of each phase according to the following set of well-known equations:
Zero-sequence component (vector)
Positive-sequence component (vector)
Negative-sequence component (vector)
Where
a
cos(
120
)
given bus.
The configuration parameter phase rotation, swaps the positive and negative sequence
components to accommodate installations with "CBA" phase rotation.
4.11 Supply Voltage and Current Unbalance (1-Cycle Update)
The supply voltage unbalance is evaluated from the symmetrical components, according to
EN61000-4-30:2003. In addition to the positive sequence component under unbalance
conditions, there also exists at least one of the following components: negative sequence
component u2 and/or zero sequence component u0.
ML0021
E
E
E
and Ea, Eb, and Ec are the fundamental vectors of a
j
*
sin(
120
)
August 15, 2018
Voltage, which places all Harmonic
A-N
0
(
Ea
Eb
Ec
)
3 /
1
(
Ea
a
*
Eb
a
*
a
2
(
Ea
a
*
a
*
Eb
A
43
The magnitudes are
*
Ec
)
3 /
*
Ec
)
3 /
Copyright 2018 Bitronics, LLC
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