Smart DFT

Hello,

I am trying to estimate a frequency of power system at the moment, but I
have got some problems with methods I have used. 

Last week I found out, the smart DFT exists. I hope, it can be a
appropriate way for me. But on the net there is not much information about
this, I mean, very interesting part of DFT.

Can somebody explain me the algorithm of smart DFT?

Thank you very much.

Mira, Czech Republic

On 3/11/13 8:26 AM, Mimar wrote:
> Hello,
>
> I am trying to estimate a frequency of power system at the moment, but I
> have got some problems with methods I have used.
>
> Last week I found out, the smart DFT exists. I hope, it can be a
> appropriate way for me. But on the net there is not much information about
> this, I mean, very interesting part of DFT.
>
> Can somebody explain me the algorithm of smart DFT?
>

reduced calories?

Apple or Android operating system?

not George W Bush?

gee, i dunno.


-- 

r b-j                  rbj@audioimagination.com

"Imagination is more important than knowledge."

> On 3/11/13 8:26 AM, Mimar wrote:
>
> Hello,
>
> I am trying to estimate a frequency of power system at the moment, but I
> have got some problems with methods I have used.
>
> Last week I found out, the smart DFT exists. I hope, it can be a
> appropriate way for me. But on the net there is not much information about
> this, I mean, very interesting part of DFT.
>
> Can somebody explain me the algorithm of smart DFT?
>

Apparently, it's a term from power systems.  There actually are some
references to a 'smart' DFT (or SDFT).  It seems it has to do with
estimating the fundamental line frequency after faults:

http://bu.umbb.dz/ressources-electroniq/Bibumbb/publication/article%20pdf/Hamid%20Bentarzi%20,%20Abderrahmane%20Ouadi%20et%20J.C.%20Maun.pdf

The 'smart' DFT is reference [15] cited in the above.  There are other
papers:

http://libra.msra.cn/Publication/1531353/a-precise-calculation-of-power-system-frequency

and

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1489295&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1489295

If you search for 'SDFT' and 'power', you can find a few more hits.

Sorry if I can't tell you much about the algorithm, though � it's a
recursive one, and seems to be specific to estimating the line
frequency quickly after a disturbance.

Kevin

>> On 3/11/13 8:26 AM, Mimar wrote:
>>
>> Hello,
>>
>> I am trying to estimate a frequency of power system at the moment, but
I
>> have got some problems with methods I have used.
>>
>> Last week I found out, the smart DFT exists. I hope, it can be a
>> appropriate way for me. But on the net there is not much information
abou=
>t
>> this, I mean, very interesting part of DFT.
>>
>> Can somebody explain me the algorithm of smart DFT?
>>
>
>Apparently, it's a term from power systems.  There actually are some
>references to a 'smart' DFT (or SDFT).  It seems it has to do with
>estimating the fundamental line frequency after faults:
>
>http://bu.umbb.dz/ressources-electroniq/Bibumbb/publication/article%20pdf/H=
>amid%20Bentarzi%20,%20Abderrahmane%20Ouadi%20et%20J.C.%20Maun.pdf
>
>The 'smart' DFT is reference [15] cited in the above.  There are other
>papers:
>
>http://libra.msra.cn/Publication/1531353/a-precise-calculation-of-power-sys=
>tem-frequency
>
>and
>
>http://ieeexplore.ieee.org/xpl/login.jsp?tp=3D&arnumber=3D1489295&url=3Dhtt=
>p%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1489295
>
>If you search for 'SDFT' and 'power', you can find a few more hits.
>
>Sorry if I can't tell you much about the algorithm, though =96 it's a
>recursive one, and seems to be specific to estimating the line
>frequency quickly after a disturbance.
>
>Kevin
>

Hello,

I decided to use smart DFT, because other ways of frequency estimation were
not working as well as I wanted. 
Last week I was testing sliding DFT with Jacobsen estimator, but I had got
some problems with frequency changes. If the signal, I focused on, had got
constant frequency, this algorithm provided excellent reesults. But if I
started  to change frequency with linear progress, it stopped working well.
Some swings and bad values have appeared there. 
So I will test SDFT next days.

Thank very much Kevin, you sent me some links.

P.S.: I am sorry, my English is not good.