VFD Motor Drive Output Question

[EdV]

I need to test inverters that are normally driven by three phase PMA
(permanent magnet alternator). Laboratory 3 phase output supplies are
mighty spendy for what I really want to use them for in a factroy
floor test.

Anybody out there tried filtering the PWM output on a VFD motor drive
to see if it can be sine wave like or at least "unspiky"?

Thanks much,
Ed V.

 

[Spehro Pefhany]

I need to test inverters that are normally driven by three phase PMA
(permanent magnet alternator). Laboratory 3 phase output supplies are
mighty spendy for what I really want to use them for in a factroy
floor test.

Anybody out there tried filtering the PWM output on a VFD motor drive
to see if it can be sine wave like or at least "unspiky"?

Thanks much,
Ed V.

You don't have 3-phase power available? Maybe you just need a
transformer.

Best regards,
Spehro Pefhany

 

[Tom2000]

I need to test inverters that are normally driven by three phase PMA
(permanent magnet alternator). Laboratory 3 phase output supplies are
mighty spendy for what I really want to use them for in a factroy
floor test.

Anybody out there tried filtering the PWM output on a VFD motor drive
to see if it can be sine wave like or at least "unspiky"?

Thanks much,
Ed V.

What a coincidence! I just ran acoss a Microchip app note last night
dealing with that very topic!

http://tinyurl.com/8z3bl

Good luck, Ed, and have fun!

Tom

 

[EdV]

You don't have 3-phase power available? Maybe you just need a
transformer.

Best regards,
Spehro Pefhany

I have 3 phase power but I need it to be around 160 to 200 VAC. 3
phase variacs are kind of pricey also particularly if you want to talk
to it(rs232).

Thanks,
Ed V.

 

[Spehro Pefhany]

I have 3 phase power but I need it to be around 160 to 200 VAC. 3
phase variacs are kind of pricey also particularly if you want to talk
to it(rs232).

Thanks,
Ed V.

There's one on eBay now with a current bit of $25 and $20 domestic US
shipping. I wonder if the bidder noticed it's a 400Hz type.


Best regards,
Spehro Pefhany

 

[John Popelish]

I need to test inverters that are normally driven by three phase PMA
(permanent magnet alternator). Laboratory 3 phase output supplies are
mighty spendy for what I really want to use them for in a factroy
floor test.

Anybody out there tried filtering the PWM output on a VFD motor drive
to see if it can be sine wave like or at least "unspiky"?

I have been involved in the use of both custom and
commercial sine filters for VFDs. Good ones usually cost
about as much as the drive. Here is an example of a
commercial brand.
http://www.transcoil.com/documents/KMG-Brochure.pdf

 

[Spehro Pefhany]

I have been involved in the use of both custom and
commercial sine filters for VFDs. Good ones usually cost
about as much as the drive. Here is an example of a
commercial brand.
http://www.transcoil.com/documents/KMG-Brochure.pdf

There are 3-phase sine wave inverters, but they are probably more
expensive again.


Best regards,
Spehro Pefhany

 

[EdV]

There are 3-phase sine wave inverters, but they are probably more
expensive again.

Best regards,
Spehro Pefhany

That is one pricey filter. It actually costs a little bit less to
have a 3 phase drive run a custom built motor generator of the same
power than use the same drive with the filter. Now of course I have
to wonder if I need the filter to protect the motor. : ) We
currently use what our vendor is supplying ofr filtering.

Thanks much,
Ed V.

 

[JosephKK]

EdV [email protected] posted to sci.electronics.design:

That is one pricey filter. It actually costs a little bit less to
have a 3 phase drive run a custom built motor generator of the same
power than use the same drive with the filter. Now of course I have
to wonder if I need the filter to protect the motor. : ) We
currently use what our vendor is supplying ofr filtering.

Thanks much,
Ed V.

Maybe not, if you buy the motor and a VFD from the same source they
are on the hook for it working. Filtering above and beyond what they
use may be irrelevant. The filter that is going to matter is the
harmonic filter between the source and the VFD.

 

[Winfield]

That is one pricey filter. It actually costs a little bit less
to have a 3 phase drive run a custom built motor generator of the
same power than use the same drive with the filter. Now of course
I have to wonder if I need the filter to protect the motor. : )
We currently use what our vendor is supplying ofr filtering.

Have you told us how much power is involved?