Hitachi WJ C1 Series User Manual

Chapter 9 Inverter Functions
9-8-3
Basic configuration and operation of PID control
◼ PID control block diagram
◼ PID operation
(1) P-operation: Operation in which the control input is proportional to the deviation
(PID target value - FB value).
(2) I-operation: Operation in which the deviation is integrated per unit time and added to the
control input. In a P-operation, changes in output are reduced as the PID target
value and FB value get closer, increasing the time required to reach the target
value, which is compensated for by the I-operation.
(3) D-operation: Operation in which the control input is proportional to the rate of change of
deviation. This effectively compensates for external disturbances.
0 to 10 VDC
4 to 20 mA
Sensor
Regular
inverter
control
Control
input
M
=
Transducer
Feedback (0 to 10 VDC / 4 to 20 mA)
-
Deviation
ε
Feed-forward (Disable / 0 to 10 VDC / 4 to 20 mA)
PID calculation
Target
value
+
+
fs
𝐾
𝑝
(1 +
1
𝑇
𝑖
∙ 𝑠
+ 𝑇
𝑑
∙ 𝑠)
Target value changes in a step response
Target value changes in a ramp response
PID target
value
Control
input
Large
P gain
Small
FB value
PID target
value
Control
input
Large
Small
FB value
P gain
Target value changes in a step response
Target value changes in a ramp response
PID target
value
Control input
Large
I gain
Small
FB value
PID target
value
Control input
Large
Small
FB value
I gain
Target value changes in a step response
Target value changes in a ramp response
PID target
value
Control input
Large
D gain
Small
FB value
PID target
value
Control input
Large
Small
FB value
D gain
A

Hitachi WJ C1 Series Specifications

General

Brand	Hitachi
Model	WJ C1 Series
Category	Inverter
Language	English