Hi community ,
Please help me in extracting the H Matrix for *DC power flow model*
For *state estimation* using the *DC power flow model*, Equation (1) can be
represented by a linear regression model following
* z=H(x)+e ........(2)*
where *H* is the Jacobin Matrix
and *z * is the matrix of real power injections in the node ( In DC
power flow we only consider active power injection in to bus)
*WLS Criteria: *
Now using the weighted least-square criteria for the calculation of
estimated following equation is used
* x_estimated= [ Inverse{ (Transpose(H)) . W. H) }
. Transpose (H).W] z .... (3)*
(W is a diagonal matrix with elements that are reciprocal of variance)
Regards
Saeed Ahmed
On 21 July 2017 at 18:33, Saeed Ahmed <[email protected]> wrote:
>
> Respected All,
>
> For Calculating the power flow
>
> 1. The state variables are related to the measurements through the
> following model:
> * z=h(x)+e .......(1)*
> here *x* is the matrix of state variables
> and *e* is the normally distributed meter error (noise) with zero
> mean in the measurements.
>
> (This is calculated this part using matpower standard Newton Raphson's
> Method)
>
>
> 2. For *state estimation* using the *DC power flow model*, Equation (1)
> can be represented by a linear regression model following
> * z=H(x)+e ........(2)*
> where *H* is the Jacobin Matrix
> and *z * is the matrix of real power injections in the node ( In DC
> power flow we only consider active power injection in to bus)
>
> *WLS Criteria: *
>
>
> Now using the weighted least-square criteria for the calculation of
> estimated following equation is used
>
> * x_estimated= [ Inverse{ (Transpose(H)) . W. H) } .
> Transpose (H).W] z .... (3)*
>
> (a diagonal matrix with elements are reciprocal of variance)
>
> **
>
> *Now My Question:*
>
> I want to know how to extract the* H *Matrix ?
>
> As per my understanding H Matrix (*Using DC Power Flow Method*) is
> different from the H Matrix ( *AC Power Flow*) and it is built as
> following:
>
> Step 1 : Build the Ybus matrix ( Need to know which function to be used ?
> Can i use the function
> [Ybus, Yf, Yt] = makeYbus(baseMVA, bus, branch)
> Is the loop for calculation of diagonal and off-diagonal elements is
> already included in this function
>
>
> Step 2 : Build the B Matrix (B=imaginary (Ybus) )
> Does this gives the correct B Matrix ?
>
> *Step 3 : Build the H Matrix *
> ( I think it should also include the bus incident matrix . How can i
> calculate/ extract the bus incidence matrix ?)
>
> *Please correct me if i am wrong in my understanding and also guide me how
> to extract H Matrix*
>
>
> Step 4 : Compare DC State Estimation using WLS function results with the
> runpf results in MATpower
>
>
> Regards
> Saeed Ahmed
>
>
> On 21 July 2017 at 14:37, Saeed Ahmed <[email protected]> wrote:
>
>> Thank you Sir .... I am really grateful...
>>
>> Now after a lot of reading and following your guidance i am understanding
>> how to start working on matpower. Your cooperation is highly appreciated. I
>> will keep on seeking guidance , please.
>>
>>
>>
>> Regards
>> Saeed Ahmed
>>
>>
>> On 20 July 2017 at 22:59, Ray Zimmerman <[email protected]> wrote:
>>
>>> For a case that has consecutive bus numbers (e.g. one that has been
>>> converted to internal indexing via ext2int()
>>> <http://www.pserc.cornell.edu/matpower/docs/ref/matpower6.0/ext2int.html>),
>>> simply use makeSbus()
>>> <http://www.pserc.cornell.edu/matpower/docs/ref/matpower6.0/makeSbus.html>.
>>> It returns the complex bus injections in per-unit, so you’ll need to take
>>> only the real part and multiply by baseMVA to get the MW values.
>>>
>>> E.g.
>>>
>>> mpc = rundcpf('case30', mpoption('out.all', 0));
>>> Pbus = real(makeSbus(mpc.baseMVA, mpc.bus, mpc.gen)) * mpc.baseMVA
>>>
>>> — Ray
>>>
>>>
>>>
>>> On Jul 19, 2017, at 9:43 PM, Saeed Ahmed <[email protected]>
>>> wrote:
>>>
>>> Hi All,
>>>
>>> I need to calculate the the injected power(Pi) matrix at each bus . It
>>> is equal to the generated power(Pg) - demand/load power. Now how to extract
>>> it using matpower
>>>
>>>
>>>
>>>
>>
>
