Inovance H3U Series - Page 313

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4
4 Instructions4.12.1 PID Calculation
Address Name Setting Range Meaning
AC Drive
Function
Code
Wire
Take-up
Parameter
Wire
Take-off
Parameter
Wire
Drawing
Machine
Parameter
S3 + 19
Upper deviation
limit
0 to 32,767
(0.1%)
Deviation end point or
user-dened switching
end point
FA-20 - - -
S3 + 20
User-dened
switching
reference
0 to 32,767
(0.1%)
Switching reference
when the parameter
switching condition is set
to 2
- - -
S3 + 21 Initial output
0 to 32,767
(0.1%)
Initial value after PID
startup
FA-21 0 0 0
S3 + 22
Initial output hold
time
0 to 32,767, in ms
Time during which the
initial value remains
unchanged
FA-22 0 0 0
S3 + 23
Output deviation
limit
0 to 32,767
(0.1%)
Range of every deviation
change
0 0 0
S3 + 24
…
S3 + 30
Internal operation - - - - - -
Address Name Meaning
D + 0 Total output PID calculation element + (D + 1)
D + 1 Main output
User-designated main output (AC drive dominant frequency)
This value is set to 0 for pure PID.
Note:
※
1: Maximum negative value of PID output. For example, if this parameter is set to 100, the maximum
negative output value is –100.
※
2: See the parameter switching principle of the position-type PID instruction.
●
PID calculation formula
u(k) = Kp {e(k) + T/Ti x ∑e(i) + Td/T x [e(k) – e(k-1)]}
u(k) Current output value ∑e(i) Current cumulative integral
Kp Proportional gain T Sampling time
e(k) Current deviation Ti Integral time
e(k-1) Deviation at the last time point Td Differential time
Sv(k) Current value Ki Integral gain
Pv(k) Current feedback value Kd Differential gain
Forward direction: e(k) = Sv(k) – Pv(k); reverse direction: e(k) = Pv(k) – Sv(k)
●
For details about parameter switching, see the position-type PID description.
●
Main output application
When (S3 + 6) = 0, (D + 1) is forcibly set to 0.
When (S3 + 6) = 1, (S3 + 7) is enabled. The maximum PID element is equal to (S3 + 1) percent of (D + 1).
Final (D + 0) = PID element + Main output (D + 1)