07 May 2008 09:06:03

jon

SMPS Design Help

Hello All, I need to design a high voltage (500V) current controlled power supply. When I say current controlled, I mean that I need to adjust the current output between 0 and 10 Amps (more would be even better). AC Input: 3 phase 208V (480V is available). Can anyone please recommend (suggest) the best topology to use? I need ripple free (very low AC ripple) DC (current and voltage). I need to charge a battery that when discharged is as low as 300VDC and when fully charged is at 490VDC. Thank you, Jon

07 May 2008 12:11:55

John Popelish

Re: SMPS Design Help

jon wrote: > Hello All, > > I need to design a high voltage (500V) current controlled power > supply. When I say current controlled, I mean that I need to adjust > the current output between 0 and 10 Amps (more would be even better). > > AC Input: 3 phase 208V (480V is available). > > Can anyone please recommend (suggest) the best topology to use? > > I need ripple free (very low AC ripple) DC (current and voltage). Please try to quantify this. Battery charging often tolerates (or even improves with) ripple. > I need to charge a battery that when discharged is as low as 300VDC > and when fully charged is at 490VDC. What should the current do when the output sees a short circuit? -- Regards, John Popelish

07 May 2008 09:32:27

jon

Re: SMPS Design Help

On May 7, 11:11=A0am, John Popelish <jpopel...@rica.net > wrote: > jon wrote: > > Hello All, > > > I need to design a high voltage (500V) current controlled power > > supply. =A0When I say current controlled, I mean that I need to adjust > > the current output between 0 and 10 Amps (more would be even better). > > > AC Input: 3 phase 208V (480V is available). > > > Can anyone please recommend (suggest) the best topology to use? > > > I need ripple free (very low AC ripple) DC (current and voltage). > > Please try to quantify this. > > Battery charging often tolerates (or even improves with) ripple. > > > I need to charge a battery that when discharged is as low as 300VDC > > and when fully charged is at 490VDC. > > What should the current do when the output sees a short circuit? > > -- > Regards, > > John Popelish I am aware that some batteries like AC ripple; however, new chemistries (Li-Ion) and old (NiMH) do not like the ripple. When I short circuit is seen by the charger the peak current should be 10 Amps or to the current set-point. Thanks,

07 May 2008 14:05:07

John Popelish

Re: SMPS Design Help

jon wrote: > I am aware that some batteries like AC ripple; however, new > chemistries (Li-Ion) and old (NiMH) do not like the ripple. (snip) So, how much ripple, either in peak to peak amperes or % of max current. There is a big difference in the design of a 10 amp regulator that has 1 amp, peak to peak ripple and one that has 1 mA peak to peak ripple. "Low ripple" is not a specification. -- Regards, John Popelish

07 May 2008 12:49:22

jon

Re: SMPS Design Help

On May 7, 1:05=A0pm, John Popelish <jpopel...@rica.net > wrote: > jon wrote: > > I am aware that some batteries like AC ripple; however, new > > chemistries (Li-Ion) and old (NiMH) do not like the ripple. > > (snip) > > So, how much ripple, either in peak to peak amperes or % of > max current. =A0There is a big difference in the design of a > 10 amp regulator that has 1 amp, peak to peak ripple and one > that has 1 mA peak to peak ripple. =A0"Low ripple" is not a > specification. > > -- > Regards, > > John Popelish Hello John, On a 10 Amps of current I can accept no more than 10 mA (5 mA or less would be ideal). Thank you, Jon

07 May 2008 23:49:09

legg

Re: SMPS Design Help

On Wed, 7 May 2008 12:49:22 -0700 (PDT), jon <JonAlbertson@yahoo.com > wrote: > >On a 10 Amps of current I can accept no more than 10 mA (5 mA or less >would be ideal). > Could you supply a battery part/type reference that justifies this ripple current limitation, while still tolerating 10A continuous charging levels? There are not many 300-500V loads that will draw current with only a 0.1% ripple component. They may require a low supply noise level, over specific frequency bands, but that is a different issue, that could be addressed with local post-regulation, independant of the actual converter, at moderate power levels. If this is an EMC consideration, you might specify a standard that allows larger current at the lower power conversion frequencies. RL

08 May 2008 21:14:04

Re: SMPS Design Help

On May 7, 8:49 pm, legg <l...@nospam.magma.ca > wrote: > On Wed, 7 May 2008 12:49:22 -0700 (PDT), jon <JonAlbert...@yahoo.com> > wrote: > > > > >On a 10 Amps of current I can accept no more than 10 mA (5 mA or less > >would be ideal). > > Could you supply a battery part/type reference that justifies this > ripple current limitation, while still tolerating 10A continuous > charging levels? > > There are not many 300-500V loads that will draw current with only a > 0.1% ripple component. They may require a low supply noise level, over > specific frequency bands, but that is a different issue, that could be > addressed with local post-regulation, independant of the actual > converter, at moderate power levels. > > If this is an EMC consideration, you might specify a standard that > allows larger current at the lower power conversion frequencies. > > RL Remember the battery burping chips? Now there is ripple for you.

10 May 2008 11:35:36

JosephKK

Re: SMPS Design Help

On Wed, 7 May 2008 12:49:22 -0700 (PDT), jon <JonAlbertson@yahoo.com > wrote: >On May 7, 1:05 pm, John Popelish <jpopel...@rica.net> wrote: >> jon wrote: >> > I am aware that some batteries like AC ripple; however, new >> > chemistries (Li-Ion) and old (NiMH) do not like the ripple. >> >> (snip) >> >> So, how much ripple, either in peak to peak amperes or % of >> max current.  There is a big difference in the design of a >> 10 amp regulator that has 1 amp, peak to peak ripple and one >> that has 1 mA peak to peak ripple.  "Low ripple" is not a >> specification. >> >> -- >> Regards, >> >> John Popelish > >Hello John, > >On a 10 Amps of current I can accept no more than 10 mA (5 mA or less >would be ideal). > >Thank you, > >Jon Another thing to think about in batteries that large is periodic "equalization" charge cycles.