| ifrythings |
Would a power supply with PFC work properly on a UPS that outputs either a "stepped sinewave" or "modified sinwave"?
I ask because if PFC is supposed to line current look like a sinewave what would it do on the other type of waveforms?
Thanks
Dave. |
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| star882 |
| It should work fine. |
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| switchmodepower |
It should shape the line current to the line voltage.
Should work fine. |
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| sawreyrw |
| Most PFCs are designed so that the input current 'tracks' the input voltage. If the voltage is not sinusoidal, the current will be distorted. I don't think this will work well. |
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| Groman |
| I would like to discuss the output of PFC circuits. Do you know what should be the output ripple voltage frequency? I think it should be 100Hz if we use 50Hz Single Phase 220Vac Source? |
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| Groman |
reply to ifrythings...
if your line voltage is sine wave then your current has to be sine wave to get PF=1 :)) if your line voltage is not sine wave for example its stepped sinewave or something different; then your current wave should be also same with it. Point is you should analyse inductor wave form and PWM outputs(Duty Cycle) which give you a good starting point... Think that line voltage(PFC input voltage ) is constant at some time interval delta (t) as a result
dV=L*di/dt
di/dt must be constant which means currnet is triangler wave
peak current value is delta(t)*V(constant) / (L)
You should ask your control chip to make input current constant at delta(t) time interval. However you have triangler sample.....
As a result PFC should not work |
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| Eva |
| Modified sinewave UPS will have trouble with the high input capacitance of high power PFC converters. Otherwise, it would work fine. |
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| Groman |
Hi Eva,
I am desiging of a PFC circuit. Before connecting it to universal input i am supplying a DC input 116Vdc to analyse everything is fine or not. Problem is MOSFET is being damaged somehow. I didnt understand why. Could you help me |
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| switchmodepower |
| quote: | Originally posted by Groman
Hi Eva,
I am desiging of a PFC circuit. Before connecting it to universal input i am supplying a DC input 116Vdc to analyse everything is fine or not. Problem is MOSFET is being damaged somehow. I didnt understand why. Could you help me |
Can you post a schematic? |
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