Re: photovoltaic array

[Michaël Kummert <kummert@xxxxxxxxxxxxx>]

Esther,

> I am working with type 94, PV array. My simulation consists on a PV array
> connected directly to the supply system through an inverter. When I set
> input 4=0 the simulation works perfectly, but if I change its value to any
> nonzero one,i.e. input 4 =1, the simulation doesn´t work properly.
> I have looked it up in Trnsys manual,Type 94 section 6 about convergence
> issues.
> As far a s I have understood, the PV convergence promotion algorithm may be
> activated by setting input 4 to any nonzero value when PV array is
> connected directly to a pump motor or other load, which I think is my case.
> But, The alternative converge promotion should be disabled by setting input
> 4 = 0 when the PV is charging a battery or whwn using a deck employing,
> which is not my case.
> Could you tell me the proper value for input 4 in my case?

I think most TRNSYS users would tell you that if it works with 0, using 
0 is the best option ;-)
More seriously, if your system converges (i.e. if you don't get many 
warnings saying that no convergence could be reached) without 
"convergence promotion", this probably indicates that you don't need it. 
In most cases, techniques that try to accelerate convergence are also 
less robust so they are likely not to converge in some cases.

My approach in your case would be:
- Try with 0 (no convergence promotion). If the simulation converges and
  does not take too long, stick with that
- If the simulation takes a long time or if you get many warnings saying
  no convergence could be reached, try with "convergence promotion" ON
  (input 4 <> 0). If it then converges, keep it. If it does not, go back
  to 0 and try reducing the time step, etc.

I hope this helps,

Michaël Kummert

--
_________________________________________________________

Michaël Kummert

Solar Energy Laboratory - University of Wisconsin-Madison
1303 Engr Res Bldg, 1500 Engineering Drive
Madison, WI 53706

Tel: +1 (608) 263-1589
Fax: +1 (608) 262-8464
E-mail: kummert@xxxxxxxxxxxxx

SEL Web Site: http://sel.me.wisc.edu
TRNSYS Web Site: http://sel.me.wisc.edu/trnsys