Multisim anyone?

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Multisim anyone?

Al-57
Hello, all. I am trying to use Multisim to simulate EV motor controller
circuits. Most contollers need isolated gate drive power supplies as well as
an isolated traction battry pack. Multisim "complains" if your circuits are
not grounded. There must be some way around this. Any ideas? Thanks, Al

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Re: Multisim anyone?

(-Phil-)
Build your sim as if "ground" is one side of the pack voltage.  In practical
application, you probably wouldn't actually "ground" the pack negative to
the chassis, but it can be thought of as a ground, and thus the spice model
won't care.

-Phil
----- Original Message -----
From: "Al" <[hidden email]>
To: "Electric Vehicle Discussion List" <[hidden email]>
Sent: Wednesday, November 28, 2007 8:40 PM
Subject: [EVDL] Multisim anyone?


> Hello, all. I am trying to use Multisim to simulate EV motor controller
> circuits. Most contollers need isolated gate drive power supplies as well
> as
> an isolated traction battry pack. Multisim "complains" if your circuits
> are
> not grounded. There must be some way around this. Any ideas? Thanks, Al
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Re: Multisim anyone?

Peter Gabrielsson
In reply to this post by Al-57
Connect a 10megaohm resistors to the floating parts. Technically they
won't be isolated anymore but for the purpose of simulation it is
close enough.



On Nov 28, 2007 8:40 PM, Al <[hidden email]> wrote:
> Hello, all. I am trying to use Multisim to simulate EV motor controller
> circuits. Most contollers need isolated gate drive power supplies as well as
> an isolated traction battry pack. Multisim "complains" if your circuits are
> not grounded. There must be some way around this. Any ideas? Thanks, Al
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>



--
www.electric-lemon.com

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Re: Multisim anyone?

Jeff Shanab
In reply to this post by Al-57
I ran in to this problem when trying to simulate an isolated dc-dc as it
has two seperate grounds. (any spice based simulation needs a ground)
I think i will put one ground and then a 1meg resistor the pseudo ground.

BTW, Does multisim have a true battery, with state of charge and
internal resistance and all or just the dc source that happens to use
the battery symbol?
I am trying to create a model for a battery either with equation based
components or the 2 capacitor model.

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Re: Multisim anyone?

Dewey, Jody R ATC COMNAVAIRLANT, N422G5G
Has anyone tried to use electronics workbench to do it?  

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On
Behalf Of Jeff Shanab
Sent: Thursday, November 29, 2007 8:59
To: [hidden email]
Subject: Re: [EVDL] Multisim anyone?

I ran in to this problem when trying to simulate an isolated dc-dc as it
has two seperate grounds. (any spice based simulation needs a ground) I
think i will put one ground and then a 1meg resistor the pseudo ground.

BTW, Does multisim have a true battery, with state of charge and
internal resistance and all or just the dc source that happens to use
the battery symbol?
I am trying to create a model for a battery either with equation based
components or the 2 capacitor model.

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For subscription options, see
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Re: Multisim anyone?

Roland Wiench
In reply to this post by Jeff Shanab
I install a battery charger circuit in the MultiSIM Simulation and just
grounded the AC input side of the battery charger only.  I found only one
ground was need to make it work.

My EV has a onboard battery charger, so I included that into the  motor
control circuit. There are two battery contactors that disconnected the
battery charger from the motor controller circuit.

Connect all the battery circuits return together instead of using a common
ground symbol.

If you click the battery symbol, the battery properties screen will appear.
In this screen you can change the tolerance in percentage of voltage.

To check to see is the battery will vary, just make a simple battery circuit
and add a variable resistance loads to it. It will start out at 0 amps and
it increase to 50 amps while the voltage vary in the tolerance I set it at.

In the motor controller circuit, you will have to add a load bank to the
motor controller so as to increase the battery ampere.  I have no motor
torque control simulator yet to perform this test.

In the battery charger circuit, the battery starts out a the voltage you
select for it and it will vary in the percentage that you set in the
tolerance selection. As the battery is charging which the voltage is set it
will vary in the percentage you have selected in the battery properties
screen as the ampere is vary.

If you have a problem with a MultiSIM circuit, you can email the simulation
it to:

  [hidden email]

They can accept MultiSIM circuits in simulator mode and they will perform a
analyses and assist in any circuit design for you. You will have to contact
first before you send your simulator circuit, because they have to set up
there computer to accept it and will instruct you on how to set your
computer for sending.  Its going into a lot of sub routines in your computer
and click that and some of this to make it work.

Roland


----- Original Message -----
From: "Jeff Shanab" <[hidden email]>
To: <[hidden email]>
Sent: Thursday, November 29, 2007 6:58 AM
Subject: Re: [EVDL] Multisim anyone?


> I ran in to this problem when trying to simulate an isolated dc-dc as it
> has two seperate grounds. (any spice based simulation needs a ground)
> I think i will put one ground and then a 1meg resistor the pseudo ground.
>
> BTW, Does multisim have a true battery, with state of charge and
> internal resistance and all or just the dc source that happens to use
> the battery symbol?
> I am trying to create a model for a battery either with equation based
> components or the 2 capacitor model.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev