8
Explanation of Functions
Explanation of Functions
Common
V/F characteristic setting
V/F characteristics setting
Output voltage gain setting
• permits selection of constant torque or reduced
torque of the V/F characteristic by means of a load. HF-320
permits selection of sensorless control as well.
• The output voltage at the base frequency can be set within
50-100% of the range by .
Use this to operate a motor with rated voltage lower than the
inverter supply voltage under optimum condition.
DC braking
DC braking function selection
DC braking frequency setting
DC braking output wait time setting
DC braking force setting
DC braking time setting
• Use DC braking during deceleration and stopping for
position and to adjust stopping accuracy.
• When the DC braking output wait time is set, the operation
during that time will be in the free-run state.
(Note 1) Disable DC braking for applications with frequent starts and
stops.
(Note 2) Excessively strong braking force may cause tripping.
Base frequency
Output voltage
Output voltage
A45
·Constant torque characteristic
100%
Base frequency
A45
·Reduced torque characteristic
100%
DC braking output
Wait time
Output
frequency
Braking
force
A52
A53
DC braking
A55
Time
Time
A54
(%)
Braking
force
Frequency
command
Upper limiter
Lower limiter
Output frequency
Upper/lower limiter
Frequency upper limiter setting
Frequency lower limiter setting
• The upper and lower limits of the output frequency can be
controlled.
Jump frequency setting
, , Jump frequency setting
,,
Jump frequency width setting
* Used to avoid resonance frequencies on the applied
machinery.
A maximum of three
jump frequencies
can be set.
Frequency command
Output frequency
Jump frequency 1
Jump frequency 2
Jump frequency 3
Deceleration
Acceleration
Jump width
PID function
PID control selection
P gain setting
I gain setting
D gain setting
PID scale setting
Feedback input method setting
Use PID operation to control processes with a feedback
signal. PID control the motor speed to drive the error
between the target value and feedback value to zero.
It is effective for controlling processes such as temperature,
pressure, flow rate, and air capacity.
〈P: Proportional control〉
In this control, the operation quantity is proportional to
the deviation of the target value and feedback value.
P gain setting K
P
• The response of the
operation quantity with
respect to deviation is adjusted.
〈I: Integral control〉
Under the proportional control alone, the operation quantity is
small when the deviation is small; therefore correction may
not be sufficient, and will not coincide with the target value.
I: Integral control is the function to correct the above.
Deviation is accumulated with the passage of time to correct
the operation quantity.
I gain setting K
I
• Integral time is set.
When the integral time
is short (I/K
I
), the
response is quick.
〈D: Differential operation〉
Differential operation uses the rate of change of the deviation
to adjust the operation quantity. It is used for correction of P
(proportional) and I (integral) control.
D gain setting K
D
PID scale setting
· This function converts the target value so that it will match
the feedback value.
permits monitoring of the value obtained by multiplying
the feedback value by the factor of .
Indication by flow rate and air capacity is also possible.
KP
Response
Stability
Large Small
Quick Slow
Unstable Stable
K
I
Response
Stability
Small Large
Quick Slow
Unstable Stable
KD
Response
Stability
Large Small
Quick Slow
Unstable Stable
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