YOKOGAWA WT500 User Manual page 44

Delta Computation (Optional; See section 5.17 for operating instructions)
Equations for Computing the Distortion Factor (See section 6.5 for operating
instructions)
IM 760201-01E
The sum or difference of the instantaneous voltage or current values (sampled data)
between the elements in a wiring unit can be used to determine various types of
data such as the differential voltage and phase voltage. This operation is called delta
computation.
Delta computation can be applied in the following ways:
• The differential voltage and differential current between two elements can be
computed on a single-phase, three-wire system or on a three-phase, three-wire
system (when using two elements).
• The line voltage and phase current that are not measured can be computed on
a single-phase, three-wire system or on a three-phase, three-wire system (when
using 2 elements).
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• Using the data from a three-phase, four-wire system, the data of a delta
connection can be computed from the data of a star connection (star-delta
transformation).
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• Using the data from a three-phase, three-wire system (three-voltage, three-
current method), the data of a star connection can be computed from the data of
a delta connection (delta-star transformation). This function is useful when you
wish to observe the phase voltage of an object that has no neutral line.
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Models with the harmonic measurement option can compute distortion factors. There are
two equations for computing the distortion factor, each with different denominators. For
information about these equations, see appendix 1.
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2.5 Computation
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App
Index
2-21