4/22/2016 2:20 PM | |
Posts: 6 Rating:
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Hi, [snip] I got a new problem.. There is a cascade control where first loop is PID controller (vessel level)and the second is PI controller (flow). Second loop works fine, but level controller works tis way: set point 10%, controller drives level to 5% set point 20% controller drives level to 10% set point 30% -.- 15% set point 40% -.- 20% set point 50% -.- 25% set point 60% -.- 30% set point 70% -.- 30% set point 80% -.- 30% set point 90% -.- 30% set point 100% -.- 30% So it sets level to half of required level until 30% level has been reached. I don't get what the problem is. ------------------------------------------------------------------------------------------ |
Last edited by: svud at: 4/22/2016 2:21:51 PMLast edited by: Min_Moderator at: 4/25/2016 8:59:56 AMNew subject after splitting Last edited by: Min_Moderator at: 4/25/2016 9:02:07 AMSplit from other thread |
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4/22/2016 6:03 PM | |
Joined: 5/28/2008 Last visit: 6/29/2024 Posts: 4510 Rating:
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Hello, Please have a look on this valuable tip from Expert hdhosseini Implementing complex loop configuration with PID controllers |
Ayman Elotaify |
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4/25/2016 9:46 AM | |
Joined: 11/21/2007 Last visit: 6/24/2024 Posts: 2324 Rating:
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Hello Your application is Similar to Steam Drum Level Control. This application basically consists of two interlinked loops. 1. Outlet Flow Loop ( Normal PID ) 2. Level Loop - ( PID with additional Feed-Forward Gain ). ( Add the actual Flow of Outlet Flow Loop as Feedforward Gain ) The Attached Application note will help you understand the application Hope this helps Cheers Navnag
AttachmentYS1700_Drum_Level_Control.pdf (118 Downloads) |
Last edited by: Navnag at: 4/25/2016 9:47:16 AMThere is no such thing as the last bug in a program |
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This contribution was helpful to
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