User manual

104 • vacon parameter descriptions
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9
1.25 EFFICIENCY OPTIMIZATION
Energy optimization, the frequency converter search for the minimum current
in order to save energy and lower motor noise, 0 = disabled, 1 = enable.
1.26 I/F START ENABLE
The I/f Start function is typically used with permanent magnet motors (PM) to
start the motor with constant current control. This is useful with high power
motors in which the resistance is low and the tuning of the U/f curve difficult.
Applying the I/f Start function may also prove useful in providing sufficient
torque for the motor at startup.
I/f Start Current
I/f Start Frequency
Output Frequency
Motor Current
Time [s]
Figure 9.3: I/f Start
1.27 I/F START FREQUENCY REFERENCE LIMIT
Output frequency limit below which the defined I/f start current is fed to mo-
tor.
1.28 I/F START CURRENT REFERENCE
The current fed to the motor when the I/f start function is activated.
1.29 VOLTAGE LIMITER ENABLE
Voltage limiter function addresses problem with very high DC-link voltage rip-
ple with 1-phase drives when fully loaded. Very high ripple in DC-link voltage
will transform to high current and torque ripple, which can disturb some us-
ers. Voltage limiter function limits maximum output voltage to bottom of DC-
voltage ripple. This reduces current and torque ripple, but decreases maxi-
mum output power since voltage is limited and more current is needed.
0 = disable, 1 = enable.