# [EVDL] Multisim anyone?



## EVDL List (Jul 27, 2007)

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" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
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
>
> _______________________________________________
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> 

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## EVDL List (Jul 27, 2007)

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.





> Al <[email protected]> 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
> ...


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## EVDL List (Jul 27, 2007)

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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## EVDL List (Jul 27, 2007)

Has anyone tried to use electronics workbench to do it? 

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Jeff Shanab
Sent: Thursday, November 29, 2007 8:59
To: [email protected]
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


----------



## EVDL List (Jul 27, 2007)

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:

[email protected]

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" <[email protected]>
To: <[email protected]>
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


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