Battery Backed 3HP AC drive system
Battery Backed 3HP AC drive system
(OP)
We use a 3HP gp motor through a VFD to drive a transmission to move a 10,000 pound gate. I've been asked to make this work on batteries. I need to come up with the most cost effective means of doing this. In similiar smaller systems, I've gotten away with a DC motor, but I need 3HP. I'm trying to figure out if I should try and run DC into the VFD bus, although I'm guessing that's going to be a lot of batteries, or venture into the 180V DC motor world, to which I am a stranger. Any offerings while I exploit google would be tremendously helpful.





RE: Battery Backed 3HP AC drive system
RE: Battery Backed 3HP AC drive system
RE: Battery Backed 3HP AC drive system
RE: Battery Backed 3HP AC drive system
RE: Battery Backed 3HP AC drive system
Keith Cress
kcress - http://www.flaminsystems.com
RE: Battery Backed 3HP AC drive system
www.KilroyWasHere<dot>com
RE: Battery Backed 3HP AC drive system
So that just means getting the right voltage on the terminals, plus figuring out how much power you need to store, i.e. how many operations do you need to hold up for? Voltage wise, I'd go for finding a 200V rated motor, which will require that you get the DC bus voltage up to 280VDC or so, which boils down to 24 x 12V batteries in series. The drive we make will continue to operate down to 190VDC, which will become about 135VAC. What that means is that down to that level, the drive will have to limit itself to about 40Hz, so as the voltage drops, your gate may have to move slower, you need to work out those details. but once you know those limits, and what is expected of the backup system, you can then size the batteries.
When all of that is done, you will need a float charger for the batteries, the VFD will not do that for you.
Good luck.
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Battery Backed 3HP AC drive system
Funny thing, the Leeson drives I use do have DC bus terminals (see 174279 for example)yet there's hardly a mention of them in the manual, and when I contact the rep/leeson, he is clueless. I think I read somewhere that these terminals were used for a braking resistor, but I never use them.
Anyways, I will not be able to suggest a battery bank, I will most likely be limited to a couple of marine batteries or similar.
I will most likely go with an inverter, and I've got a 5A (smart) charger I use in other designs.
I will most definitely be coming back here to give status and ask more questions, no doubt about that.
Your input is invaluable, thank you for the reply!
Mark
RE: Battery Backed 3HP AC drive system
Now here's the prob;em. I have no idea which way they are doing it on those lenze / AC Tech / Leeson drives. The B+ and B- terminals are used to connect to an external braking module., Lenze part #845-206. If you read the quasi-manual they have available for that unit, it starts off describing what I would think is a stand-alone DB braking module where the DB chopper would be external to the drive. But later in the manual, they contradict themselves and even go on to say that the DB Brake module they sell is NOT capable of being used with another VFD, because the B+ and B- terminals are in come way "communicating" to the module. That implies that there is something else inside the VFD besides just a simple DC bus terminal there. Not very well written or described I'm afraid.
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Battery Backed 3HP AC drive system
http://magnumenergy.com/
http://magnumenergy.com/wp-content/uploads/2013/07...
We supplied a MS4024PAE to a customer for their 24vdc batt to run our 5hp servos for off grid testing..... IIRC, this 5kw output for 30 sec unit was only a couple thousand dollars?
www.KilroyWasHere<dot>com