Справочник Пользователя для Mitsubishi Electronics FR-A700
361
Special operation and frequency control
4
4.25 Special operation and frequency control
4.25.1 PID control (Pr. 127 to Pr. 134, Pr. 575 to Pr. 577)
Purpose
Parameter that must be Set
Refer
to Page
Perform process control such as pump and air
volume.
volume.
PID control
Pr. 127 to Pr. 134,
Pr. 575 to Pr. 577
Switch between the inverter operation and
bypass operation to operate.
bypass operation to operate.
Bypass-inverter switchover
function
function
Pr. 135 to Pr. 139, Pr. 159
Increase speed when the load is light.
Load torque high speed
frequency control
frequency control
Pr. 4, Pr. 5, Pr. 270 to Pr. 274
Frequency control appropriate for the load torque
Droop control
Pr. 286 to Pr. 288
Frequency setting by pulse train input
Pulse train input
Pr. 291, Pr. 384 to Pr. 386
Make the motor speed constant by encoder
Encoder feedback control
Pr. 144, Pr. 285, Pr. 359,
Pr. 367 to Pr. 369
Avoid overvoltage alarm due to regeneration by
automatic adjustment of output frequency
automatic adjustment of output frequency
Regeneration avoidance
function
function
Pr. 882 to Pr. 886
The inverter can be used to exercise process control, e.g. flow rate, air volume or pressure.
The terminal 2 input signal or parameter setting is used as a set point and the terminal 4 input signal used as a
feedback value to constitute a feedback system for PID control.
The terminal 2 input signal or parameter setting is used as a set point and the terminal 4 input signal used as a
feedback value to constitute a feedback system for PID control.
Parameter
Number
Name
Initial
Value
Value
Setting
Range
Description
127
PID control automatic
switchover frequency
switchover frequency
9999
0 to 400Hz
Set the frequency at which the control is automatically
changed to PID control.
changed to PID control.
9999
Without PID automatic switchover function
128
PID action selection
10
10
PID reverse action
Deviation value signal input
(terminal 1 )
11
PID forward action
20
PID reverse action
Measured value (terminal 4 )
Set point (terminal 2 or Pr. 133)
21
PID forward action
50
PID reverse action
Deviation value signal input
(L
ON
W
ORKS
, CC-Link communication)
51
PID forward action
60
PID reverse action
Measured value, set point input
(L
ON
W
ORKS
, CC-Link communication)
61
PID forward action
129
*1
PID proportional band
100%
0.1 to 1000%
If the proportional band is narrow (parameter setting is small),
the manipulated variable varies greatly with a slight change of
the measured value. Hence, as the proportional band narrows,
the response sensitivity (gain) improves but the stability
deteriorates, e.g. hunting occurs.
Gain Kp = 1/proportional band
the manipulated variable varies greatly with a slight change of
the measured value. Hence, as the proportional band narrows,
the response sensitivity (gain) improves but the stability
deteriorates, e.g. hunting occurs.
Gain Kp = 1/proportional band
9999
No proportional control
130
*1
PID integral time
1s
0.1 to 3600s
When deviation step is input, time (Ti) is the time required for
integral (I) action to provide the same manipulated variable as
proportional (P) action.
As the integral time decreases, the set point is reached earlier
but hunting occurs more easily.
integral (I) action to provide the same manipulated variable as
proportional (P) action.
As the integral time decreases, the set point is reached earlier
but hunting occurs more easily.
9999
No integral control
131
PID upper limit
9999
0 to 100%
Set the maximum value. If the feedback value exceeds the
setting, the FUP signal is output. The maximum input (20mA/
5V/10V) of the measured value (terminal 4) is equivalent to
100%.
setting, the FUP signal is output. The maximum input (20mA/
5V/10V) of the measured value (terminal 4) is equivalent to
100%.
9999
No function
132
PID lower limit
9999
0 to 100%
Set the minimum value. If the measured value falls below the
setting range, the FDN signal is output. The maximum input
(20mA/5V/10V) of the measured value (terminal 4) is
equivalent to 100%.
setting range, the FDN signal is output. The maximum input
(20mA/5V/10V) of the measured value (terminal 4) is
equivalent to 100%.
9999
No function
133
PID action set point
9999
0 to 100%
Used to set the set point for PID control.
9999
Terminal 2 input is the set point.