Example Of Temperature Control - Panasonic AFPE224300 User Manual

8.4 Example of temperature control

- Example of auto-tuning
Control cycle: Ts = K100 (1 s)
Selected parameter: Proportional gain (Kp) = K171 (17.1), Integral time (Ti) = K600 (60 s),
Temperature (∗0.1 ℃)
⋅ The temperature input conversion for FP-e is performed every 250 ms. The average cycle (1 to 50
times) can be set using the system register 409. The initial setting is "0." (Average: 20 times)
When the heat capacity of the control system is small and heating/cooling is performed at high
speed, set a value for the average time to a smaller one.
⋅ Executing the auto-tuning sets the parameters suitable for any control system automatically.
Optimum control can be conducted by changing the values (1/2 to 2 times).
Generally, Kp (proportional gain) affects on the response characteristics. As the value of Kp
becomes larger, the response error becomes smaller. When the value is too large, however, it may
cause the hunting. Ti (Integral time) greatly affects on the response characteristics. As the value of
Ti becomes smaller, the response becomes faster. When the value is too small, however, it may
cause the overshoot.
- Example of PID parameter characteristics
When Ti is changed to 30, 60, 90, and 120 under the conditions as follows:
Ts = 250, Kp = 300, Td = 1
- Example of PID processing
PID control mode: Ts = 250, Kp = 300, Ti = 60, Td =
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Derivative time (Td) = K150 (15 s)
Output (%)
Time (∗2 sec.)
8-11