Pid Control - Hitachi SJ100 Instruction Manual

PID Control

When enabled, the built-in PID loop calculates an ideal inverter output value to cause a
loop feedback process variable (PV) to move closer in value to the setpoint (SP). The
current frequency command serves as the SP. The PID loop algorithm will read the
analog input for the process variable (you specify the current or voltage input) and calcu-
late the output.
• A scale factor in A_75 lets you multiply the PV by a factor, converting it into
engineering units for the process.
• Proportional, integral, and derivative gains are all adjustable.
• See "PID Loop Operation" on page 4–39
Func. Name /
Code SRW Display
A_71 PID Enable
PID SW
A_72 PID proportional gain
PID P
A_73 PID integral time
constant
PID I 001.0s
A_74 PID derivative time
constant
PID D
A_75 PV scale conversion
PID CONV 01.00
A_76 PV source setting
PID INPT
NOTE: The setting A_73 for the integrator is the integrator's time constant Ti, not the
gain. The integrator gain Ki = 1/Ti. When you set A_73 = 0, the integrator is disabled.
"A" Function
Description
Enables PID function,
two option codes:
OFF
00... PID Disable
01... PID Enable
Proportional gain has a range
of 0.2 to 5.0
1.0
Integral time constant has a
range of 0.0 to 150 seconds
Derivative time constant has a
range of 0.0 to 100 seconds
00.0
Process Variable (PV) scale
factor (multiplier), range of
0.01 to 99.99
Selects source of Process
Variable (PV), option codes:
CUR
00... [OI] terminal (current in)
01... [O] terminal (voltage in)
SJ100 Inverter
for more information.
Run
Mode
–FE
Edit
(CE)
✘
00
✘
1.0
✘
1.0
✘
0.0
✘
1.00
✘
00
3–19
Defaults
–FU –FR
Units
(UL) (Jpn)
00 00 —
1.0 1.0 —
1.0 1.0 sec.
0.0 0.0 sec.
1.00 1.00 —
00 00 —