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IM 760301-01E
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App
Index
Faunctional Description
2.5
Computation
By using the data of measurement functions, the following computations can be
performed. In addition, a function is provided in which the equation used to determine the
measurement function data can be selected.
User-Defined Functions «For procedures, see section 5.4.»
Equations can be created (defined) by combining the measurement function symbols
and operators. The numeric data corresponding to the equation can then be determined.
The combination of a measurement function and element number (U1:U(E1, ORT), for
example) constitutes an operand. 20 equations (F1 through F20) can be defined.
• Operator
There are 11 operators: +, –,
∗
, /, ABS (absolute value), SQR (square), SQRT (square
root), LOG (logarithm), LOG10 (common logarithm), EXP (exponent), and NEG
(negation).
• Number of Operands
There can be up to 16 operands in one equation.
MAX Hold «For procedures, see section 5.5.»
Holds the maximum value of the numeric data. The measurement function of which the
maximum value is to be held is specified using the user-defined function.
Setting the Average Active Power «For procedures, see section 5.6.»
The average active power can be computed on devices on which the power fluctuates
such as an intermittent control device. The computing equation for average active power
is specified using the user-defined function.
Setting the Computing Equation for Efficiency «For procedures, see section 5.7.»
By setting equations for
η
1 to
η
4, the input/output efficiency of a device can be
measured. For example, if the input power to a device is P
Σ
A and the output power is
P
Σ
B, the power conversion efficiency of the device can be computed by setting the
equation
η
= (P
Σ
B)/(P
Σ
A)
×
100. On models with the motor evaluation function (motor
version), the energy conversion efficiency of the motor can be computed by setting the
equation
η
= ((Pm)/(P
Σ
A)
×
100) or ((Pm)/(P
Σ
B)
×
100).
Setting the Efficiency Compensation «For procedures, see section 5.8.»
Compensates for the measurement loss that occurs due to the wiring used for
measurement or the internal impedance of the power meter. There are two functions
used to compensate for the loss caused by the measurement instrument. For details,
see appendix 8.
• Wiring Compensation
Compensates for the loss caused by the wiring system of each element.
• Efficiency Compensation
The power measurement on the secondary side of a power transformer such as an
inverter includes loss caused by the measurement instrument. This loss appears as
error in the efficiency computation. This function compensates for this loss.