YOKOGAWA WT210, Руководство пользователя, Страница: 41 / 316

1-4
IM 760401-01E
Computation Function
Apparent Power, Reactive Power, Power Factor and Phase Angle
Based on the measurement values of voltage, current and active power, the values of
apparent power, reactive power, power factor and phase angle can be computed.
Scaling
When performing voltage or current measurements with items such as external PT,
CT, shunt, and external sensor (clamp), you can set a scaling factor to the primary/
secondary ratio. This is called scaling. This function enables display of the measured
values of voltage, current, active power, reactive power, integrated current and
integrated power factor in terms of primary-side values.
Averaging
This function is used to perform exponential or moving averaging on the measured
values before displaying them when the measured values are not stable.
Efficiency (applicable only to the WT230)
Efficiency can be computed on models with multiple input elements.
Crest Factor
This function determines the crest factor of the voltage and current using peak/RMS
values.
Four Arithmetic Operation
Displays six types of computed results. (A+B, A–B, A
×
B, A/B, A
2
/B, A/B
2
)
Average Active Power during Integration
This function computes the average active power within the integration period. It is
derived by dividing the watt hour (integrated active power) by the elapsed time of
integration.
Integrator Function
This function enables integration of active power and current. The integrated value (watt
hour or current hour) and the elapsed time of integration as well as other measured
(computed) values can be displayed even while the integration is in progress. Moreover,
since integrated values of negative polarity can be displayed, the consumed watt hour
(ampere hour) value of the positive side and the watt hour value returning to the power
supply of the negative side can be displayed separately.
Frequency Measurement Function
This function measures the frequency of the voltage or current.
Measurable range: 0.5 Hz to 100 kHz (The measurement range varies depending on the
display update rate.)
Harmonic Measurement Function (Option)
This function enables the computation of voltage, current, active power and so forth of up
to the 50
th
order, the relative harmonic content of harmonic orders, and the phase angle
of each order with respect to the fundamental (first order) on a single selected input
element. Furthermore, the total rms value (funda harmonic) of the voltage,
current and active power, and the harmonic distortion factor (THD) can be calculated.
Store/Recall Function of Measured/Computed Data and Setup Parameters
This function enables the storage of measured/computed data and setup parameters in
the internal memory. The stored measured/computed data and setup parameters can be
recalled, and the data can be displayed or output via the communication interface.
D/A Output Function (Option)
This function converts the measured values of voltage, current, active power, apparent
power, reactive power, power factor, phase angle, frequency, voltage peak, current
peak, and integrated values to DC analog voltage with full scale of
±
5 V and outputs the
voltage. Output items of up to 12 output channels (4 channels on WT210) can be
selected.
1.2 Functions