Description of Function Codes
MD380 User Manual
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Group A5: Control Optimization Parameters
Function Code Parameter Name Setting Range Default
A5-00 DPWM switchover frequency upper limit 0.00–15.00 Hz 12.00 Hz
This parameter is valid only for V/F control.
It is used to determine the wave modulation mode in V/F control of asynchronous motor.
If the frequency is lower than the value of this parameter, the waveform is 7-segment
continuous modulation. If the frequency is higher than the value of this parameter, the
waveform is 5-segment intermittent modulation.
The 7-segment continuous modulation causes more loss to switches of the AC drive but
smaller current ripple. The 5-segment intermittent modulation causes less loss to switches
of the AC drive but larger current ripple. This may lead to motor running instability at high
frequency. Do not modify this parameter generally.
For instability of V/F control, refer to parameter F3-11. For loss to AC drive and temperature
rise, refer to parameter F0-15.
Function Code Parameter Name Setting Range Default
A5-01 PWM modulation mode
0: Asynchronous modulation
1: Synchronous modulation
0
This parameter is valid only for V/F control.
Synchronous modulation indicates that the carrier frequency varies linearly with the change
of the output frequency, ensuring that the ratio of carrier frequency to output frequency
remains unchanged. Synchronous modulation is generally used at high output frequency,
which helps improve the output voltage quality.
At low output frequency (100 Hz or lower), synchronous modulation is not required. This is
because asynchronous modulation is preferred when the ratio of carrier frequency to output
frequency is high.
Synchronous modulation takes effect only when the running frequency is higher than 85 Hz.
If the frequency is lower than 85 Hz, asynchronous modulation is always used.
Function Code Parameter Name Setting Range Default
A5-02
Dead zone compensation
mode selection
0: No compensation
1: Compensation mode 1
2: Compensation mode 2
1
Generally, you need not modify this parameter. Try to use a different compensation mode
only when there is special requirement on the output voltage waveform quality or oscillation
occurs on the motor.
For high power AC drive, compensation mode 2 is recommended.
Function Code Parameter Name Setting Range Default
A5-03 Random PWM depth
0: Random PWM invalid
1–10
0
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