With the same PID parameters, what is the reason for such a large difference in the blade opening angles of the two sets of fans?
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The guide vanes of the two air handling units are adjusted based on the same differential pressure signal, and the PID parameters used for adjustment are identical; then why is there a large difference in the opening degrees of the guide vanes?
Carefully analyze whether the characteristics of the engineering objects are consistent; it is not necessarily a problem with the instrument parameters.
With the same PID parameters, the opening degree will still vary; look for other causes.
The input signals are all the same; could it be because two PID controllers are being used?
Are the operating conditions the same, and is the air compressor the same? You can’t just focus on the instrumentation side
Are the guide vanes products from the same manufacturer? Also, does each machine have its own valve at the outlet, and are their opening degrees consistent? ~~
The analysis suggests that the issue may be caused by a delay in the time it takes for the differential pressure signal to reach the control cabinet; the two PID controllers are located in different cabinets, and the signal from one instrument is sent to these cabinets in two separate paths
The guide vanes are of the same model, and the fan outlet valve is fully open
It’s probably because the adjustment mechanisms are different. The PID parameters need to be adjusted based on the actual conditions.
This is quite normal; after all, they are not controlled by the same PID, so the equilibrium states of the two systems differ.
With the same controlled variable, different regulators and actuators each forming a closed loop – what type of control scheme is this?