Hitachi WJ C1 Series User Manual

Chapter 9 Inverter Functions
9-8-5
3 Setting the PID target value input source and feedback input source
 Set the PID feedback value input source with "PID feedback input source selection [A076]",
and the PID target value input source with "Frequency input source selection [A001]
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"
.
 If the PID feedback input source is "[Ai2] terminal input (00)" or "[Ai1] terminal input (01)",
and the PID target value input source is "Control terminal (01)", the "AT selection [A005]" will
be disabled, and the analog input not set by [A076] becomes the target value input source.
(Example) If [A076] is "[Ai2] terminal input (00)" and [A001] is "Control circuit terminal
block (01)", the PID target value input source is the [Ai1] terminal input.
 If the PID feedback value input source is "Modbus communication (02)", write the feedback
value in the holding register address 0006h, with 10000 being 100%.
Register
number
Code
Item
R/W
Data range
Resolution (%)
0006h
-
PID feedback
R/W
0 to 10000
0.01 (%)
(Note) This register is only writable when [A076] is set to "Modbus communication (02)".
 If the PID target value input source or PID feedback value input source is "Pulse input", the
value retrieved is converted to a percentage of the maximum frequency (100%), with the
maximum frequency being the pulse frequency set in "Pulse frequency scale [P055]". For
details on pulse frequency commands, refer to "9.2.8 Setting Pulse Input as the Frequency
Command Input Source".
 If the PID target value input source or PID feedback value input source is the "Calculation
function result," refer to "9.2.11 Setting a Calculation Operation on Two Frequency
Commands as the Frequency Command Input Source" for details.
4 Setting and adjusting proportional gain, integral gain, and derivative gain
 Set the "PID proportional gain [A072]", "PID integral gain [A073]," and "PID derivative gain
[A074]" according to the actual control target.
 If the response is not stable in PID operation, refer to the procedure below to make
adjustments.
Event ▷
Example of countermeasures
 Even when the PID target value fluctuates,
output response is slow, and the feedback value
changes slowly.
Increase the "PID proportional gain [A072]".
 Feedback values change quickly and are not
stable.
 Overshooting and hunting occur.
Decrease the "PID proportional gain [A072]".
 Feedback values gradually fluctuate.
 There is a delay before operations stabilize.
Increase the "PID integral time constant
[A073]".
 The PID target value and feedback value do not
match easily.
Decrease the "PID integral time constant
[A073]".
 There is a slow response even when proportional
gain is increased.
 Small-scale hunting occurs.
Increase the "PID derivative gain [A074]".
 There is a greater susceptibility to external
disturbances, and operations take longer to
stabilize.
Decrease the "PID derivative gain [A074]".
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. "2nd-motor control [SET]" target parameter. The second control parameter is also subject to setting.

Hitachi WJ C1 Series Specifications

General

Brand	Hitachi
Model	WJ C1 Series
Category	Inverter
Language	English