Hitachi WJ C1 Series

Chapter 9 Inverter Functions
9-8-1
9.8 Driving by PID Process Control
9.8.1 Using PID Control
 How to perform process control for the flow rate, air volume, pressure, and other
measurements?
 How to switch between PID control and normal control?
 How to soft start the pump to avoid the water hammer phenomenon?
 How to stop the motor to save energy when the flow rate, air volume, pressure, and other
measurements exceed a certain output?
 Use this function to perform process control for the flow rate, air volume, pressure, and other
measurements. To use this function, set "PID enable [A071]" to "Enable (01)" or "Enable (with
inverted output) (02)".
 When the input terminal function "Disable PID [PID] (23)" is on, the PID function is disabled and
the inverter operates according to the frequency command selected for the target value.
 PID output can be limited based on the PID target value using "PID output range [A078]".
 PID control allows the use of feed-forward input that attempts to pre-stabilize any external
disturbances.
 A sleep mode is available when operation is stopped to reduce downtime and improve energy
efficiency.
 If the acceleration/deceleration time setting is longer than the PID operation, following the
output frequency may delay and PID control may not be successful. In this case, reduce the
acceleration/deceleration time.
 The frequency upper and lower limit function ([A061]/[A261]/[A062]/[A262]) apply to
frequency command by the PID output. They do not apply to PID target value.
 When using an analog input for the PID target value/feedback value, do not set the "Analog
input filter time constant [A016]" to "31 (500 ms filter ±0.1 Hz with hysteresis)". This may cause
operations to become unstable.
Code
Item
Description
Data
[d004]
PID feedback value
monitor
Displays the PID feedback data multiplied
by the [A075] scale value.
0.00 to 9999.00 (%)
[d153]
PID deviation
monitor
Displays the PID deviation amount
multiplied by the [A075] scale value.
-9999.00 to 9999.00 (%)
[d155]
PID output monitor
Displays the PID output value after the
limiter has been applied.
-100.00 to 100.00 (%)
[A071]
PID enable
Disable
00
Enable
01
Enable (with inverted output)
02
[A072]
PID proportional
gain
Sets the PID proportional gain.
0.00 to 25.00
[A073]
PID integral time
constant
Sets the PID integral gain.
0.0 to 3600.0 (s)
[A074]
PID derivative gain
Sets the PID derivative gain.
0.00 to 100.00 (s)
[A075]
PID scale
Data for unit conversion for PID feedback
monitors, etc.
0.01 to 99.99
[A076]
PID feedback input
source selection
[Ai2] terminal input (current input)
00
[Ai1] terminal input (voltage input)
01
Modbus communication (RS-485)
02
Pulse train frequency
03
Calculation function result
10
[A077]
PID deviation
inversion
Disable
00
Enable
01
[A078]
PID output range
The PID output changeable range is
limited by the PID target value ± this set
value. Set in units of %, with the maximum
frequency being 100%.
0.0 to 100.0 (%)
Q
A
!