Correct. The PD and QD are not variables in F, simply fixed parameters. So
there is no need to take partials with respect to them … they would be all
zeros.
Ray
> On Apr 23, 2015, at 9:38 PM, Ji Chen <[email protected]> wrote:
>
> Ray.
> Thank you for your responses.
> The "match" in my last email means one measurement in z should have a
> corresponding sub-matrix of the measurement Jacobian H, when compute
> F = H'*R_inv*(z-z_est) . But the bus power injections and the partial
> derivatives of it don't have the same form, the former includes the local PD
> and QD
> while the latter doesn't. May the "the partials of those terms are zero" is
> the reason, is it?
> Thanks again.
> Ji
>
>
>
>
>
> At 2015-04-23 23:18:15, "Ray Zimmerman" <[email protected]> wrote:
> See my responses below …
>
>> On Apr 23, 2015, at 5:15 AM, 陈吉 <[email protected] <mailto:[email protected]>>
>> wrote:
>>
>> When compute net injection at generator buses in the m file doSE.m line
>> 107-110, the local PD and QD are include.
>>
>> %% compute net injection at generator buses
>> gbus = gen(:, GEN_BUS);
>> Sgbus = V(gbus) .* conj(Ybus(gbus, :) * V);
>> Sgen = Sgbus * baseMVA + (bus(gbus, PD) + j*bus(gbus, QD)); %% inj S +
>> local Sd
>>
>> While when compute partial derivatives of the complex bus power injections
>> in dSbus_dV.m line 9, local PD and QD are unincluded.
>>
>> % S = diag(V) * conj(Ibus) = diag(conj(Ibus)) * V
>
> This is because the loads, PD and QD are assumed to be constant with respect
> to voltage (i.e. the partials of those terms are zero).
>
>> Can the sub-matrix of z_est real(Sgen(idx_zPG)) and the sub-matrix of H
>> dPG_dVa(idx_zPG, nonref) dPG_dVm(idx_zPG, nonref) match?
>
> I’m not sure what you mean by “can … match”? The former is a vector, the
> latter is a matrix.
>
>> Best regards!
>> Jimmy
>>
>>
>
>
>
