YOKOGAWA PZ4000, Руководство пользователя

Страница: 343 / 417

15-20
IM 253710-01E
15.8 Computing the Motor Efficiency and Total
Efficiency
From the active power measured by the power measurement module and the motor
output determined in section 15.7, the PZ4000 can compute the motor efficiency (ratio of
the motor output versus the power consumption by the motor) and total efficiency (ratio
of the motor output versus the power consumption by the motor as well as the converter
through which power is fed to the motor). Computation examples are indicated below.
When the Motor Input Is a Three-Phase Four-Wire System (3P4W)
• Wire (see chapter 3) the motor input to elements 1, 2, and 3.
• Select [3P4W] for the wiring method (see sections 3.7 and 5.2).
×
100
Motor output
*
(W)
Σ
A(W)
Motor efficiency
η
mA(%) =
* Motor output derived in section 15.7.
Motor Motor output
Power consumption
by the motor
Σ
A = P1 + P2 + P3
When the Converter Input and Motor Input Are Both Single-Phase Two-Wire Systems
(1P2W)
• Wire the converter input to element 1 and the motor input to element 2.
• Select [1P2W-1P2W] for the wiring method.
×
100
Motor output
*
(W)
Σ
B(W)
Motor efficiency
η
mB(%) =
×
100
Motor output
*
(W)
Σ
A(W)
Total efficiency
η
mA(%) =
* Motor output derived in section 15.7.
Converter Motor Motor output
Σ
B = P2
Σ
A = P1
Power consumption
by the motor Power consumption
by the motor and
converter
When the Converter Input Is a Single-Phase Two-Wire System (1P2W) and the Motor
Input Is a Three-Phase Three-Wire System (3P3W)
• Wire the converter input to element 1 and the motor input to elements 2 and 3.
• Select [1P2W-3P3W] for the wiring method.
×
100
Motor output
*
(W)
Σ
B(W)
Motor efficiency
η
mB(%) =
×
100
Motor output
*
(W)
Σ
A(W)
Total efficiency
η
mA(%) =
* Motor output derived in section 15.7.
Converter Motor
Motor output
Σ
B = P2 + P3
Σ
A = P1
Power consumption
by the motor Power consumption
by the motor and
converter