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Re: [TRNSYS-users] Type 108 5 stage zone thermostat



Stefano -

Since controllers may oscillate between control states during a timestep, most controller models in TRNSYS include some form of "stickiness" where after a number of oscillations during a timestep the control will "stick" to a control state.  The introductory material of the controllers section of the Mathematical Reference volume of the manual set has a good discussion of "stickiness" in controller models.

The warning message you see is informing you of the percentage of the simulation time where the control has to stick to a control state.  If the percentage is low then there is likely nothing to worry about.  However, if the controller is stuck a high percentage of the time you should likely look to some strategies to improve the convergence of your model (reduce the timestep, change the order of your components, add capacitance to your system, etc).  If you controller is stuck 100% of the time it is likely that your model is not well formed.

Regards,

Tim

 

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Timothy P. McDowell Executive Vice President Thermal Energy System Specialists, LLC 22 N Carroll St, Suite 370 Madison, WI 53703 608-274-2577

On 2016-08-03 05:01, Stefano Tosoni via TRNSYS-users wrote:

Dear all,

I have a problem with my simultation: I have a building with multiple thermal zones and for each zone I have a type 108 for control my fancoil during the cooling season.
The simulation run but in the Lst file I have some 'warning' like: "the controller was stuck during xx percent of the time during the simulation".
 
What does it mean?
 
thanks,
Stefano

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