Delta DVP-ES2/EX2/SS2/SA2/SX2/SE manual Step, Application

DVP-ES2/EX2/SS2/SA2/SX2/SE Operation Manual - Programming

Step 2:

When KP is 40, response overshoot occurs, so we will not select it.

When KP is 20, PV response is close to SV and won’t overshoot, but transient MV will be to large due to a fast start-up. We can put it aside and observe if there are better curves.

When KP is 10, PV response is close to SV and is smooth. We can consider using it. When KP is 5, the response is too slow. So we won’t use it.

Step 3:

Select KP = 10 and increase KI gradually, e.g. 1, 2, 4, 8. KI should not be bigger than KP. Then, increase KD as well, e.g. 0.01, 0.05, 0.1, 0.2. KD should not exceed 10% of KP. Finally we obtain the figure of PV and SV below.

1.5

PV=SV

1

0.5KP=10,KI =8,KD=0.2

00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Time (sec)

Application 1:

PID instruction in pressure control system. (Use block diagram of example 1) Control purpose:

Enabling the control system to reach the target pressure. Control properties:

The system requires a gradual control. Therefore, the system will be overloaded or out of control if the process progresses too fast.

Suggested solution:

Solution 1: Longer sampling time

Solution 2: Using delay instruction. See the figure below

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