Simone and Shri,
I’ve looked at this a bit and I’m not sure I agree. First of all, Simone, I
can’t seem to create a case that demonstrates what you are seeing (unless by “a
little reactive power output” you mean something non-zero on the order of the
termination tolerances. So, could you please send me a small example off-list?
And Shri, while I agree there is a small bug in the handling of generator
reactive power at PQ buses, I don’t think it has anything to do with the
charging capacitance of connected lines. In fact, I think the total reactive
power injection at the bus is correct. The only issue is that the total is
distributed proportionally among all of the generators at the bus, as opposed
to leaving the allocations as specified in the input. In any case, I think your
suggested patch will not be correct, since gbus and on could then be of
different dimension.
Let me know if you still think I’m missing something,
Ray
On Oct 8, 2014, at 2:46 PM, Abhyankar, Shrirang G. <[email protected]> wrote:
> Simone,
> I think the smallish reactive power output from the generator that you
> are seeing is due to the reactive power supplied by the line charging
> capacitance(s) of the transmission line(s) connected to it. Instead of
> what I suggested earlier, you could set the generator output as negative
> load in the bus data struct (and set its bus type to PQ).
>
> @Ray: I think the proper fix for this is by applying the following patch
> in pfsoln.m that excludes generators at PQ buses from gbus.
>
> - gbus = gen(on, GEN_BUS); %% what buses are they at?
> + gbus = find(bus(gen(on,GEN_BUS),BUS_TYPE)~=PQ) %% Only include
> generator buses with types PV and REF.
>
>
> Shri
>
> -----Original Message-----
> From: Simone Cochi <[email protected]>
> Reply-To: MATPOWER discussion forum <[email protected]>
> Date: Wed, 8 Oct 2014 16:01:05 +0200
> To: MATPOWER discussion forum <[email protected]>
> Subject: Generators as negative loads
>
>> Hello there,
>> I asked months ago if I could simulate photovoltaic generators as PQ
>> negative loads in order to see the the voltage profile modifications
>> caused by injection of the generators.Someone advised me to put the
>> generator in the generator struct and to mark bus type as PQ (1). I
>> notice that even if I put reactive power output to zero in the
>> generator and bus struct, I have a little a little reactive power
>> output from the photovoltaic generator in the results. Someone can
>> explain me this behaviour?
>>
>> Thank you very much
>>
>> Simone
>>
>
>
>
