Mitsubishi Electric FR-E 500 Instruction Manual page 150

(2) PID action overview
1) PI action
A combination of proportional control action (P) and integral control action (I) for
providing a manipulated variable in response to deviation and changes with time.
[Operation example for stepped changes of process value]
Note: PI action is the sum of P and I
actions.
2) PD action
A combination of proportional control action (P) and differential control action (D)
for providing a manipulated variable in response to deviation speed to improve the
transient characteristic.
[Operation example for proportional changes of process value]
Note: PD action is the sum of P and D
actions.
3) PID action
The PI action and PD action are combined to utilize the advantages of both
actions for control.
Note: The PID action is the sum of the
P, I and D actions.
Deviation
P action
I action
PI action
Process
value
P action
D action
PD action
Process
value
P action
I action
D action
PID action
135
PARAMETERS
Set point
Process value
Time
Time
Time
Set
point
Deviation
Time
Time
Time
Set point
Deviation
Time
Time
Time
2
y=at +bt+c
Time
4