Richard:
Are you sure that you want to specify the power injections of the
photovoltaic generators as zero in a power flow?
The trapezoidal model for (P,Q) feasibility is intended for use in an
optimal power flow setting, not a power flow setting. If you have all
generators with Pg = 0 then you may not have enough generation to meet
the demand. Do you have additional, traditional generators?
In a power flow, the reactive dispatches are found such that the voltage
at the bus is at the specified Vg. In an optimal power flow, the
reactive dispatches are modulated to obtain an optimal voltage profile.
Which is it that you want to achieve? Do you want to solve a power flow
or an optimal power flow?
Richard Ngonga wrote:
Hi ,
I have modelled 20 photovoltaic generators in a 100 bus radial
distribution network with the parameters shown below(in the generator
field). The problem I am having is that when I model the nodes with
the Photovoltaic generators as PV buses the AC Newton Raphson loadflow
does not coverge, but when I model the same nodes as swing
buses(option 3) the network converges. My aim is to model
the photovoltaic generators as var controllers, is there a way this
can be done in Matpower?
Pg=0
Qg=0
Pmin = 0
Pmax = 0
Qmax = 0.01563
Qmin = -0.01563
mBase=100
Pc1 = 0
Qc1min = 0
Qc1max = 0
Pc2 = 0.032
Qc2min = -0.01563
Qc2max = 0.01563
Richard Ngonga
> Date: Thu, 30 Aug 2012 21:36:52 -0400
> Subject: Re: Photovoltaic Generators modelling
> From: [email protected]
> To: [email protected]
>
> Assuming that you want to specify a reactive dispatch capability
> within the .9 power factor cone that we talked about earlier, and
> assuming Pmin = 0 and Pmax = 1MW, then at Pmax the reactive dispatch
> could be in [-0.4843, 0.4843] MVAr. Then, the following parameters
> define that cone for Matpower:
>
> Pmin = 0
> Pmax = 0
> Qmax = 0.4843
> Qmin = -0.4843
> Pc1 = 0
> Qc1min = 0
> Qc1max = 0
> Pc2 = 1
> Qc2min = -0.4843
> Qc2max = 0.4843
>
>
>
>
> On Thu, Aug 30, 2012 at 4:56 PM, Richard Ngonga
<[email protected]> wrote:
> >
> > Hi Carlos,
> >
> > Do I have to model photovoltaic generators in matpower like diesel
> > generators? My aim is to model photovoltaic inverters as dispatchable
> > reactive power sources using Matpower's trapezidal modeling of the
(P,Q)
> > feasible region. What is the best way to model them in matpower?
> >
> > Regards
> >
> > Richard
> >
> >> Date: Mon, 20 Aug 2012 12:23:10 -0400
> >> From: [email protected]
> >> To: [email protected]
> >> Subject: Re: PV Generators and Transformer modelling
> >>
> >> So, if the reactive dispatch of your generators is constrained to be
> >> within a 0.95 power factor, then you can use MATPOWER's trapezoidal
> >> modeling of the (P,Q) feasible region. as opposed to simple bound
> >> constraints on P and Q
> >> for a generator. In your case, if Pmin reaches down to 0, then
you have
> >> more of a cone instead of a trapezoid.
> >> This is best explained using a picture; see manual for details.
> >>
> >> carlos.
> >>
> >> Richard Ngonga wrote:
> >> > Thanks for that, I mean photo voltaic. I am modelling PV generators
> >> > that are able to dispatch reactive power(i.e operating at -0.95 to
> >> > 0.95 power factor).
> >> >
> >> >
> >> > > Date: Mon, 20 Aug 2012 01:34:09 -0400
> >> > > From: [email protected]
> >> > > To: [email protected]
> >> > > Subject: Re: PV Generators and Transformer modelling
> >> > >
> >> > > Um, an unfortunate crisscross with acronyms... by PV
generators do you
> >> > > mean power-voltage as in classical power flow problem
parlance or do
> >> > you
> >> > > rather mean "photo voltaic"?
> >> > >
> >> > > Richard Ngonga wrote:
> >> > > >
> >> > > > Hi there,
> >> > > >
> >> > > > I am working on a thesis on reactive power control on a
distributed
> >> > > > network with transformers and PV generators. Can I model
the PVs as
> >> > > > generators on a PV bus or should I model them as capacitors
on a PQ
> >> > > > bus? I'm also having problems modelling transformers from a
20KV
> >> > > > network to a 0.4KV network; when I use the transformer
ration 50 I
> >> > get
> >> > > > very large power flows and losses. The transformer data is: Sn
> >> > 400KVA,
> >> > > > Usc=10%, Uprm/Usec=20/0.4(KV) and Usec set=1.05.
> >> > > >
> >> > > > Regards
> >> > >
> >> > >
> >>
> >>
>
