[EnergyPlus_Support] Re: P or PI control

["Ooi" <ooi_kb3@xxxxxxxxxxx>]

Thanks Phil

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Philip Haves <phaves@...> wrote:
>
> To clarify:
> 
> There is no persistent offset in (proportional + integral (PI) control 
> but there is a persistent offset in proportional-only (P) control.  The 
> effect of the integral action in a (well tuned) PI controller is to 
> reduce the offset to zero on a timescale comparable to the response time 
> of the plant.  If this response time is short compared to the timescales 
> of interest in the simulation, as it is for most HVAC loops (excluding 
> zone temperature control and thermal storage tank control), then PI 
> control is a very good approximation to the ideal control assumed in 
> EnergyPlus.
> 
> Phil
> 
> On 5/20/2012 4:48 PM, Ooi wrote:
> >
> > This was explained last week. The time step integration among the 
> > simulation managers is something better than PI, i believe. In PI 
> > control, there will be an offset from the setpoint. EP Simulation does 
> > not have these offset. It was explained that the offset depends on the 
> > proportional band, which is very closely related to gain in the P.
> >
> > Hopw this helps.
> > ooi
> >
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx 
> > <mailto:EnergyPlus_Support%40yahoogroups.com>, "ohchoen" <ohchoen@> 
> > wrote:
> > >
> > > Hi, I'd like to know that it is possible P or PI Control using EP.
> > > is it possible??
> > >
> >
> > 
> 
> -- 
> Philip Haves
> Leader, Simulation Research Group
> Lawrence Berkeley National Laboratory
> One Cyclotron Road, MS 90R3111
> Berkeley, CA 94720-8134
> (510) 486 6512 (office)
> (510) 486 4089 (fax)
>




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