DC to 3ph AC

[alexbeatle]

Hello, folks.
Is it possible to use a 3ph drive (ex. AB PF525 or 527) to run the 3ph ac motor with encoder using a HV battery pack (277VDC (battery empty)...350VDC (battery full)). I'm thinking AB PF525 or 527, 'cause I used them extensively before)

This will skip the drive's conversion from AC to DC and just use the inverter.

Curious if anybody experimented with this.
Thanks in advance

 

[GaryS]

I have done common buss systems before
What you want to is possible but a few things to keep in mind
Most vfd’s require ac power in on L1 and L2 to supply power to the control board
Without power to the control the vfd wouldn’t work. There are a few vfd’s that allow the control board to be directly powered from a dc source or even power the control board from the dc buss Yaskawa allows for the external control power. So select your hardware carefully

 

[5618]

The voltage range you have is lower than the normal DC bus range of a 480V PowerFlex 525. I don't think you're below the threshold for a DC bus undervoltage fault, but I'm not certain. You won't get 480V at full speed. You might have to play with the V/F curve to avoid some problem I don't exactly know just thinking about it, or keep the speed below some level where V/F matches a normal application.

You're in the DC bus range of a 240V drive, but you might need some voltage regulation at full battery charge to avoid DC bus overvoltage faults, depending on the threshold for that alarm.

 

[alexbeatle]

Did you need to setup any pre-charge circuitry to not block the inverter capacitors when connecting directly to the DC bus?