MATPOWER does not model unbalanced 3-phase systems, and without a lot of work
to refresh my memory, I’m not comfortable commenting on the possibility of a
good single-phase approximation in your case.
Maybe someone else can comment.
Ray
> On Jun 18, 2015, at 8:24 PM, Thai Tran <[email protected]> wrote:
>
> Hi Dr.Zimmerman,
>
> I'm new to matpower so please excuse me if this is a silly question.
>
> I'm trying to use matpower to calculate power flow for a distribution grid.
> This circuit has power coming from a substation on 12.47 kV three phase line.
> Single phase transformers tap off the three phase line and step the voltage
> down to 120V to serve houses in the circuit. In matpower, transformers are
> modeled as a branch, how should I model the connections in my circuit?
>
> For example:
> substation is connected to transformer 1 which is then connected to 5 loads.
> In the circuit model it would be
> substation -> transformer
> transformer -> load 1
> ...
> transformer -> load 5
>
> Should I model this in the branch matrix as
>
> substation(node 1) -> load 1 (node 2)
> ...
> substation(node 1) -> load 5 (node 6)
> load 1(node 2) -> load 2 (node 3)
> ...
> etc.
>
>
> Also since the transformer step the voltage level from 12.47kV to 120V, which
> level should I use to calculate my p.u impedance?
> Thank you
> Thai
