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Hamid Hamza , 02-06-2024, 03:20 PM

Hello everyone
I have to design a power board for a three-phase induction motor
The inverter DC link bus can be connected:
1- directly to the DC link of a three-phase diode rectifier
2- or to an external DC link (such as batteries or Photovoltaic pannel)
Please, in my schematic (altium design), how to illustrate this scenario.

Robert Feranec , 02-06-2024, 04:22 PM

Usually I would do this through variants - fitted / unfitted components for different situations. If something is connected externally, this can be done via a connector or pads where you solder wires (add these to schematic).

Hamid Hamza , 02-06-2024, 04:23 PM

Professor, can i use a jumper?

Robert Feranec , 02-06-2024, 04:24 PM

I am not sure what currents will flow there

Hamid Hamza , 02-06-2024, 04:26 PM

The DC link current is 6A

Hamid Hamza , 02-06-2024, 04:29 PM

sometimes, i will connect directly the rectifier output to the inverter DC link
and also, sometimes i will use an external Dc link to supply the inverter

Robert Feranec , 02-06-2024, 04:31 PM

if you mean using a standard jumper, i don't think they are designed for that high currents, you can double check datasheet.

Hamid Hamza , 02-06-2024, 04:31 PM

yes sir

QDrives , 02-06-2024, 08:59 PM

There are 2 solutions:
1) Connect the DC supply to two of the AC inputs.
2) Have a separate DC bus and AC in connections. This eliminates losses in the diodes (~ 2x 1V), but increases cost and complexity. Do make sure that the diodes now need to be able to take the current continues rather than spread over 3 diodes (or 6, depending on how you want to look at it.)

Hamid Hamza , 02-07-2024, 04:19 PM

@Robert Feranec and @QDrives Thanks for your advices

Hamid Hamza , 02-07-2024, 04:30 PM

Hamid Hamza , 02-07-2024, 04:31 PM

here's the schematic diagram I made

Hamid Hamza , 02-07-2024, 04:33 PM

Hamid Hamza , 02-07-2024, 04:34 PM

Hamid Hamza , 02-07-2024, 04:44 PM

In this schematic, I want:
1- sometimes connect directly the rectifier output (rect+ and rect-) to the inverter input (DC + and DC-);
2- also sometimes i could use and external DC voltages (Ext_DC+ and Ext_DC-)

Hamid Hamza , 02-07-2024, 04:49 PM

please provides comments and suggestions

Hamid Hamza , 02-07-2024, 06:19 PM

@Robert Feranec please can i use this option ?
https://resources.altium.com/p/solder-bridge-jumper-best-practices-pcb-design
To connect the external DC link to the inverter sometimes?

QDrives , 02-07-2024, 09:42 PM

Better set your grid to 100 mil, otherwise you might encounter some nasty errors when your first board arrives.

Hamid Hamza , 02-07-2024, 10:20 PM

@QDrives ok thank you

Hamid Hamza , 02-08-2024, 04:21 PM

Hello everyone

Hamid Hamza , 02-08-2024, 04:54 PM

here is how i think i could :
1- sometimes i will connect the rectifier output to the inverter DC link (red lines)
2- sometimes i will an external DC link output to the inverter DC link (blue lines)

I will use a jumper (with 76A load current) to make the connections : https://www.phoenixcontact.com/en-us/products/jumper-fbs-2-12-3005950

Hamid Hamza , 02-08-2024, 04:57 PM

Please ,
is this the right way to do it?

QDrives , 02-08-2024, 10:35 PM

In all the advanced AC drives I have worked with, they BOTH have AC (three phase) inputs and DC bus connections.
76A is some serious current and best not driven as DC over diodes.
The problem with the jumper is that when someone forgets that the jumper is placed in DC mode, an AC supply connection would blow up your drive and possibly more.
If you have dedicated AC and DC connectors, one can still connect it wrong, but at least see 3 versus 2 connections (ignoring Neutral and Protected Earth here for simplicity).
If the cost for multiple connectors would be to much, use a variant in Altium and only mount one of the two.

Hamid Hamza , 02-09-2024, 07:06 AM

@QDrives Thanks