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| 5/6/2008 8:59 PM | |
Joined: 1/5/2007 Last visit: 4/7/2023 Posts: 1690 Rating:
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hi, I have some comments to the solution concept of ROSA: 1. I think if you have two identical pumps in your system, then it is the best concept to control both over the hole area from 0% to 100% power with one 0-10V-signal from one PI-Controller (that means parallel). Because the both pumps then have the same load-program ant the same life time AND you have no steps or additional peaks in your system (in your controlled and measured signal). 2. Only if you have two different pumps or other reasens to work with 2 steps (that means with two controlling cases: one pump<--> two pumps) then you need the ground concept from ROSA! Aboutthis concept I have the followed comments: a) To cut the two cases you need an analoge thresholdtrigger and of cause the parameters of this should be different with ON > OFF to have a hysteresis between the use of one and two pumps. But this is not enough. You should add an On- and OFF-time delay directly after this analoge thresholdtrigger to suppress signal peaks (high/low signals with verry short time in relation to your normal signal). b) To start thesecond pump only ON/OFF is bad,because in this (not only short) moment you have two bumps with full power and your controlled/measured signal makes a verry big peak or step! To solve this problem you should use two analoge outputs and two inverters (changed with the thresholdtrigger) to controll your pumps separatly - set a ramp-function direct before the analoge output of the pump you want to start/stop. The speed of the changing this ramp must be (a little bit) lower as the reaction speed of the PI-controller of the first pump. In this case the second pump starts with low power and this power is going higer then with the ramp and so the PI-controller can reduce the power of the first (and controlled) pump continuous. The result is, that you have no peak (and no step) in your controlled/measured signal! And the rampis better for the life time of the pump too. In the othercase if the second pump must be go OFF itthis goes inverted and the second pump goes OFF with the inverted ramp and the PI-controller can make the power of the first pump higher.... I hope this comments help you to controll your system in a right way... Best regards Betel |
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==> Meine TAG-Listen: "deut." |
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| 5/7/2008 8:59 AM | |
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Posts: 2 Rating:
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Thank you I willgive it a try, i will also take into consideration the acceleration and deaceleration of theinverter. the daddy |
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