I’m working on a project where I have multiple servo axes (18 axes) and I don’t know the correct approach how to combine passive filters to use one on more drives, when to connect DC bus(if even connect). Usually when I was working with Acopos P3 I had every drive on separate passive line filter and separate circuit breaker. Now I have multiple drives which do vertical movement and want to use DC bus sharing and sharing braking resistors (like if I had Acopos Multi configuration). Any suggestion would help. BR
having more ACOPOS P3 drives (e.g. with a shared DC bus connection) behind 1 line filter is possible.
In the ACOPOS P3 user’s manual V1.40 ENG beginning on page 398 you can find relevant information. Please consider also some requirements stated there, e.g. just up to 6 ACOPOS P3 drive behind 1 filter are allowed, on top of that also the maximum total motor cable length depends on the PWM switching frequency, etc.
For sizing a braking resistor or for finding out if a braking resistor acutally is needed, I would suggest to do that in ServoSoft. There the entire drive configuration as well as the movement profile of the individual axes can be taken into consideration.
Thank you for your answer. I saw this page in manual, but I’m still not sure how to do It. If I get in my case then I have 5 Acopos P3 Single station 13A and 1 Acopos P3 Dual Station 8.8A in one cabinet. So I can have a circuit breaker with 50Amps going through 55A passive line filter and connect this main power supply to how many drives? First 2,3 and then other drives only with DC Bus? Also I will be using integrated braking resistor in all drives if this is correct? Or should I go with one bigger external and connect to middle drive (if it’s needed as you said to check in servo soft. Also I don’t have the program and I think you need licence for it).
you can connect up to 6 ACOPOS P3 drive to 1 passive filter. But please consider the total allowed motor cable length (75m in case of 5kHz).
Apart from that, there are more possible ways, how a DC bus network can be designed. Either all drives can be connected to the AC supply and additionally via the DC bus to each other.
But there is also the possibility to connect a drive to the DC bus network just via the DC bus connection without the need of the AC supply.
This difference also needs to be taken into account for selecting the fuse(s) for the drives:
Depending on how much current is drawn from your ACOPOS P3 drives continously, either 1 8B0F055 filter can be used (when being below 55A) or a 2nd filter
of the same type can also be used in parallel in case of having higher continous currents in total:
Maybe 2 8B0F055 filters in parallel would work in your case, when all the axis need the nominal current of the drive.
When you connect drive only via the DC bus, the drive where an AC supply also is available needs to charge the DC bus capacitance of the other drives as well.
There is a limitation which is documented here:
For sizing of the braking resistor there would also be a chapter in the user’s manual V1.40 beginning on page 412. There formulas can be found.
If not being able to use ServoSoft, I would suggest to start by checking the movement profile of 1 drive first and see, if there are braking situations which would
lead to regeneration. After doing that for all the drive, it then additionally can be checked, if the regenerative energy would be absorbed by other drives in the DC,
which in the same time would draw power from the DC bus. Important for the selection of the resistor are then phases, where lots of regenerative energy is available
and no or less power is drawn from the DC bus.
