The shunts are not included in the loss numbers, so everything does add up.
Generation = 5.4 MW
Loads = 4.9 MW
Losses = 0.4 MW
Shunt Inj = –0.1 MW
Generation + Shunt Inj = Loads + Losses
5.4 – 0.1 = 4.9 + 0.4
Ray
> On Nov 29, 2018, at 10:06 AM, José Paulos <[email protected]> wrote:
>
> Hi Ray, thanks for your input.
>
> In fact, we weren't considering that. However:
>
> When analyzing the case_info we get:
>
> Shunt Injections
> active (MW) -0.1
> reactive (MVAr) 3.6
>
> I'm assuming that those are simplified values, but in our network, we have:
>
> Sum of the GS Shunt Conductances = 0.0865 MW
> Difference between calculated losses vs. get_losses = 0.095 MW (that were
> supposedly due to the missing GS values)
> Resulting a difference of 0.0085 MW (even this is different from the -0.1 MW
> active shunt injections).
>
>
>
>
>
> José Paulos
> Centro de Sistemas de Energia
> Centre for Power and Energy Systems
>
> INESC TEC
> Campus da FEUP
> Rua Dr Roberto Frias
> 4200-465 Porto
> Portugal
>
> T +351 91 424 1519
> F +351 22 209 4050
> [email protected] <mailto:[email protected]>
> www.inesctec.pt <http://www.inesctec.pt/>
>
> On 27-Nov-18 20:03, Ray Zimmerman wrote:
>> You are missing contribution of the shunt elements defined in the GS and BS
>> columns of the bus matrix. These also contribute to the overall power
>> balance. Have a look at …
>>
>> case_info(powerflow)
>>
>> … after running your test_file.
>>
>> Ray
>>
>>
>>> On Nov 27, 2018, at 11:53 AM, José Paulos <[email protected]
>>> <mailto:[email protected]>> wrote:
>>>
>>> Hi,
>>> We have a network with the following configuration:
>>> %% system MVA base
>>> mpc.baseMVA = 100;
>>>
>>> %% system voltage levels (kV)
>>> mpc.V_levels = [
>>> 0.4 15.0 30.0 60.0
>>> ];
>>>
>>> %% system summary
>>> % number of buses: 41 (1 REF | 1 PV)
>>> % number of branches: 41 (8 transformers)
>>> % number of loads: 21 (including Pd/Qd = 0)
>>> % number of generators: 2
>>> % number of capacitors: 2
>>>
>>> We use get_lossses, in this case:
>>>
>>> %%% compute the losses
>>> losses = get_losses(powerflow);
>>> %%% the active losses
>>> active_losses = sum(abs(real(losses)));
>>>
>>> The balance between the injected active power and the Loads/Gen's is not
>>> equal to the result of the get_lossses procedure described.
>>> Follows attached the case (run test_file.m with test_network.mat in the
>>> same dir)
>>>
>>> Thanks in advance,
>>>
>>> --
>>>
>>>
>>> José Paulos
>>> Centro de Sistemas de Energia
>>> Centre for Power and Energy Systems
>>>
>>> INESC TEC
>>> Campus da FEUP
>>> Rua Dr Roberto Frias
>>> 4200-465 Porto
>>> Portugal
>>>
>>> T +351 91 424 1519
>>> F +351 22 209 4050
>>> [email protected] <mailto:[email protected]>
>>> www.inesctec.pt <http://www.inesctec.pt/>
>>>
>>> <test_file.m><test_network.mat>
>>
>
