Power factor correction
in [Design]
|
From: MooseFET on 24 Jan 2010 12:22 On Jan 24, 9:14 am, "JosephKK"<quiettechb...(a)yahoo.com> wrote: > On Sun, 24 Jan 2010 08:04:24 -0800, Fred Abse <excretatau...(a)invalid.invalid> wrote: > >On Tue, 19 Jan 2010 04:26:37 -0800, JosephKK wrote: > > >> Thanks Fred. I am learning some stuff about spice from this. It seems the > >> power factor is not so bad as the harmonics. > > >The way true and apparent power were calculated should include the effect > >of harmonics. > > While is most certainly does include the power in the harmonics, it does not > calculate the spectral power of each of the various harmonics. I am > interested in the harmonic power by harmonic number. It is often better to start off with knowing the real power. Stripping that out of the waveform makes the wave form you need to process much easier to deal with. Only if the FFT in spice works on exactly an integer number of cycles does it make the FFT into a single spike. The tail of the skirt on the fundamental shifts the other harmonics up.
From: JosephKK on 25 Jan 2010 21:30
On Sun, 24 Jan 2010 09:22:46 -0800 (PST), MooseFET <kensmith(a)rahul.net> wrote: >On Jan 24, 9:14 am, "JosephKK"<quiettechb...(a)yahoo.com> wrote: >> On Sun, 24 Jan 2010 08:04:24 -0800, Fred Abse <excretatau...(a)invalid.invalid> wrote: >> >On Tue, 19 Jan 2010 04:26:37 -0800, JosephKK wrote: >> >> >> Thanks Fred. I am learning some stuff about spice from this. It seems the >> >> power factor is not so bad as the harmonics. >> >> >The way true and apparent power were calculated should include the effect >> >of harmonics. >> >> While is most certainly does include the power in the harmonics, it does not >> calculate the spectral power of each of the various harmonics. I am >> interested in the harmonic power by harmonic number. > >It is often better to start off with knowing the real power. >Stripping that out >of the waveform makes the wave form you need to process much easier to >deal with. >Only if the FFT in spice works on exactly an integer number of cycles >does it >make the FFT into a single spike. The tail of the skirt on the >fundamental shifts >the other harmonics up. I studied the impacts of various windowing schemes some 25 years ago. |