For Temperature Control Improvement - Daikin AKZ9 Series Instruction Manual

PIM00318A_EN.fm Page 30 Tuesday, October 26, 2010 12:37 PM

For Temperature Control Improvement

∗ To use the Oil Cooling Unit in normal conditions, this function is not required.
Outline of the function
Depending on the system of the main machine, problems of "unstable temperature control" or "slow response in temperature
control" may be raised. In such cases, it is possible that the temperature control gain
∗ Temperature control gain: Coefficient to determine a control value according to deviation (temperature difference)
In such cases, you can improve the temperature control performance by using the "Auto-tuning mode" that provides more
suitable gain settings.
Auto-tuning (Conceptual drawing)
When temperature control is unstable
Target temperature
0
When temperature control
response is slow
Target temperature
0
Parameter No.
P/I gain calculation coefficient (Response coefficient)
n005
n006 Temperature control gain P (for low deviation)
Temperature control gain I (for low deviation)
n007
Temperature control gain P (for high deviation)
n008
Temperature control gain I (for high deviation)
n009
Outline of operation
The auto-tuning mode executes the following steps.
Check the Oil Cooling Unit status in each step.
Step
Before start
Step 0
Checking tuning conditions
Step 1
Operation for stabilizing initial status
Step 2 Operation for collecting control target data
Calculation of temperature control gain P
Step 3
and I from collected data, and writing gain
into each parameter
After completion
30
P: Proportional gain
I: Integral gain
Auto-tuning
(P: Small, I: Large)
T: Time
Auto-tuning
(P: Large, I: Small)
T: Time
Item
Operation
Operation status
–
(Operation mode: Other than 9)
Operation status
(Operation mode: Other than 9: Same as before start)
Operation status
(Automatic operation for 2 minutes at 1% capacity)
Operation status
(Automatic operation for 10 minutes at 100% capacity)
–
—"Auto-tuning mode"
∗
P or I setting is not suitable for the system.
Improved temperature control
Target temperature
0
The auto-tuning mode automatically writes calculated values of
temperature control gain (P and I) into specified parameters.
Factory settings of the standard model
P: 40
I: 40
Unit status
Stop
Stop
High deviation
Low deviation
T: Time
High deviation
Initial value: 2.0
Calculated temperature control gain P
Calculated temperature control gain I
Remarks
Select a desired operation mode.
∗[Note] 1., 3.
∗[Note] 4.
∗[Note] 5.
∗[Note] 6.