Example: Automatic DC braking when stopping the motor
In order that the DC braking is automatically active when the motor is stopped, the corresponding operating threshold must be set in 0x2B84:003 (P704.03).
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After a stop command, the motor is first decelerated as set. Once the output frequency falls below the set operating threshold, the inverter stops the deceleration and activates DC braking.
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DC braking is carried out with the braking current set in 0x2B84:001 (P704.01) for the hold time set in 0x2B84:002 (P704.02).
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The exact behavior depends on the stop method set in 0x2838:003 (P203.03).
Stop method = "Standard ramp [1]"
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Parameter
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Name
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Setting for this example
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Enable inverter
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Digital input 1 [11]
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Run
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Digital input 2 [12]
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Reset fault
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Not connected [0]
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Stop method
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Standard ramp [1]
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Frequency control: Default setpoint source
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Frequency preset 1 [11]
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Frequency setpoint presets: Preset 1
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40 Hz
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Current
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50%
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Automatic hold time
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10 s
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Automatic operating threshold
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15 Hz
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The status signals can be assigned to digital outputs.
 Configure digital outputs |
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①
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With the stop method "Standard ramp [1]", the motor is first decelerated normally until the value falls below the operating threshold set in 0x2B84:003 (P704.03).
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②
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The motor coasts down for a specified time. This "demagnetizing time" serves to reduce the induced voltage.
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③
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The DC braking becomes active for the hold time set in 0x2B84:002 (P704.02).
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④
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If the inverter is disabled, the motor coasts. (DC braking is only possible if the inverter is enabled).
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⑤
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If there is a new start command within the hold time, the DC braking is cancelled. The motor is accelerated to the setpoint again.
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Stop method = "Quick stop ramp [2]"
Same behavior as with the stop method "Standard ramp [1]", except that the motor is decelerated with the quick stop ramp instead of the standard ramp.
Stop method = "Coasting [0]"
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Parameter
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Name
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Setting for this example
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Enable inverter
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Digital input 1 [11]
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Run
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Digital input 2 [12]
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Stop method
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Coasting [0]
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Frequency control: Default setpoint source
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Frequency preset 1 [11]
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Frequency setpoint presets: Preset 1
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40 Hz
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Current
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50%
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Automatic hold time
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10 s
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Automatic operating threshold
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15 Hz
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The status signals can be assigned to digital outputs.
Configure digital outputs |
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①
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With the stop method "Coasting [0]", the motor first coasts down for a specified time. This "demagnetizing time" serves to reduce the induced voltage.
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②
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The DC braking becomes active for the hold time set in 0x2B84:002 (P704.02).
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③
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If the inverter is disabled, the motor coasts. (DC braking is only possible if the inverter is enabled).
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④
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If there is a new start command within the hold time, the DC braking is cancelled. The motor is accelerated to the setpoint again.
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