Mitsubishi Electric MELSEC iQ-F FX5 - Page 652

650
35 CPU MODULE BUILT-IN ANALOG FUNCTION
35.6 Function (PID Control Via Parameter)
■Auto-tuning calculation formula
*1 KP: Proportional gain, KPh: Heating proportional gain, KPc: Cooling proportional gain, : Ratio of a circle's circumference to its diameter,
Ymax: Maximum process value, Ymin: Minimum process value, Ti: Integral time (s), Td: Derivative time (s), T
Int
: Cycle start time (ms),
T
Final
: Cycle end time (ms)
Operation expression
*1
Item Operation expression usage timing
Proportional gain • Heating control of standard PID control
• Cooling control of PID control
Heating proportional
gain
• At the 3rd cycle of heating-cooling PID control (when the ambient temperature setting is
enabled, target value  ambient temperature)
Cooling proportional
gain
• Up to the 3rd cycle of heating-cooling PID control (when the ambient temperature setting
is enabled, target value < ambient temperature)
Heating proportional
gain
• Heating-cooling PID control (when the ambient temperature setting is disabled)
• Up to the 2nd cycle of heating-cooling PID control (when the ambient temperature setting
is enabled, target value  ambient temperature)
• Up to the 2nd cycle of heating-cooling PID control (when the ambient temperature setting
is enabled, target value < ambient temperature)
Cooling proportional
gain
• Heating-cooling PID control (when the ambient temperature setting is disabled)
• Up to the 2nd cycle of heating-cooling PID control (when the ambient temperature setting
is enabled, target value  ambient temperature)
• Up to the 2nd cycle of heating-cooling PID control (when the ambient temperature setting
is enabled, target value < ambient temperature)
Integral time • Heating control of standard PID control
• Cooling control of PID control
• Heating-cooling PID control (when the ambient temperature setting is disabled)
• Heating-cooling PID control (when the ambient temperature setting is enabled, target
value  ambient temperature)
• Heating-cooling PID control (when the ambient temperature setting is enabled, target
value < ambient temperature)
Differential time • Heating control of standard PID control
• Cooling control of PID control
• Heating-cooling PID control (when the ambient temperature setting is disabled)
• Heating-cooling PID control (when the ambient temperature setting is enabled, target
value  ambient temperature)
• Heating-cooling PID control (when the ambient temperature setting is enabled, target
value < ambient temperature)
π(Y
max
-Y
min
)
K
p
=0.588×
4
π(Y
max
-Ymin)
K
ph
=0.588×
((Y
max
-SV)+(SV-Y
min
))
×
4
SV-Y
min
π(Y
max
-Y
min
)
K
pc
=0.588×
((Y
max
-SV)+(SV-Y
min
))
×
4
Y
max
-SV
T
i
=0.5×(T
Final
-T
Init
)÷1000
T
d
=0.125×(T
Final
-T
Init
)÷1000