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Hi all,
Find attached a program I wrote for my groundsource heatpump. Everything seems to be working fine except my two pi controlers which I cannot get working. These pi controllers work fine when simulated, but when run on the system they do not respond at all..
If anyone can help me just to get the pi controller working in heating modethat would be phenomenal.
I have two pt100 sensors coupled to a Logo RTD module,on the input and output pipes on the water side of the heatpump. The water pump is inverter driven, with a 0-10V output from logo to command it.
When the heatpump is in heating mode I want the water pump to be running at a miniumumwater flow rate, but I want the pi controller to start increasing the flow rate on the pump when the temperature difference starts to gotoward a setpoint of -2 degrees centigrade.
The following has been setup:-
The two temperature sensors are inputed on blocksAI5 and AI6, wherethe analog amplifiers (B002, B010)are used to offset the error in the sneosrs.
The analoge comparator (B006)monitors the temp diffrence and switches beween cooling and heating mode.
An analogue math block (B016)is used to calculate the temperature difference from the analogue amplifiers. This value is then inputed into the pi block (B037)
The pi's output value is thenpassed through another analogue math block (B041) and an analogue ramp block (B045), before being outputted as a (0-10V) output at AQ1 to the inverter.
Good luckwith this one,
Adam