
Can A Ac Drive Give Output Voltage More Than The Supply Voltage.
#1
Posted 09 May 2008 - 10:33 AM
All inverters are specified that Output voltage can be max equal to input voltage(Ac to AC converter). Is their any inverter available, which can provide more output voltage than the supply voltage.
Regards,
#2
Posted 09 May 2008 - 11:07 AM
Welcome to the forum.
A VFD operates by rectifying the incoming supply voltage converting it to DCvoltage. This DC voltage is then chopped up to convert it back to AC voltage. The maximum output AC voltage is limited by the maximum DC voltage which is limited by the AC input voltage, so the only way to get a higher output voltage is to include a transformer at the output or the input.
Best regards,
Mark
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#3
Posted 11 May 2008 - 03:26 AM
#4
Posted 11 May 2008 - 03:31 AM
Best regards,
Mark Empson | administrator
Skype Contact = markempson | phone +64 274 363 067
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#5
Posted 12 May 2008 - 04:41 AM
Best regards,
Dear Marke and Jraef,
Thank You very much for your answers .
As you said Input RMS ac is convereted in to Dc And then converted again in to Ac . I assumes some percenatge of losses during this conversion???.
And hence the out put should be less than the input RMS value. I want to know 
#6
Posted 12 May 2008 - 07:36 AM
Yes, you are correct, the output voltage for a pure clean sinewave current is lower than the input due to the voltage drops in the circuit, but a small amount of 3rd harmonic can be introduced into the waveform to lift the effective voltage.
The best output voltage will be achieved in inverters that do not use DC bus chokes or AC Line reactors. This causes the rectifier to act as a peak rectifier and results in the maximum DC voltage.
If a DC bus choke is used, the rectifier will act more like an averaging rectifier.
Good question.
Best regards,
Mark Empson | administrator
Skype Contact = markempson | phone +64 274 363 067
LMPForum | Power Factor | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | Pressure Transducers | Smart Relay | GSM Control | Mark Empson Website | AuCom | Soft Starters
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