How can I make a “power-controlled” current source in ISIS?

[mobesa]

I'm trying to simulate the electro-thermal behavior of an IGBT in a Boost DC-DC Converter (100 Vin - 400 Vout, 8kW Output Power) using Proteus VSM/ISIS. The electro part was easy as pie. However, I couldn't figure out how to extract the active power dissipated by the IGBT. I'll be using the real-time value of dissipated power by plugging it in a current source, which will be used in an equivalent thermal circuit like so:
http://i.stack.imgur.com/nfymj.png

I tried:

The Laplace Multiply Operator to multiply voltage and current. I really don't know how it works, but someone who's supposed to know told me that it multiplies voltages. So, I figured if I could put a Current-Controlled Voltage Source on where I want to get current from and then link its positive terminal, along with the voltage across the IGBT, to the Multiply Operator, I'll get a voltage equivalent to power in value. TL;DR Here's a screenshot of what I did (but this is just a test to get the output power):
https://i.stack.imgur.com/BYwwB.png
Then all I had to was to hook its output to a voltage-controlled current source...

A Multiplying Voltage Source. Like so:
http://i.stack.imgur.com/3xjZX.png
Same logic as the aforementioned suggestion...

When I tried both suggestions, I got zero-output voltage. I couldn't get any further...

I searched for an answer, but I couldn't find one.

So my question is: Is there another way to make a sort of "power-controlled" current source?

I know it is possible in LTSpice (or other circuit simulators) using an Arbitrary Behavioral Current Source..

Thanks!

[Ettore]

Load current must be measured in series with the load resistor R1 not in parallel.

[mobesa]

Load current must be measured in series with the load resistor R1 not in parallel.

Thanks Ettore... I didn't see that coming

Now, I've managed to get things working for the load power like so:
http://i.stack.imgur.com/NocTN.png


But, when I turned to the IGBT to get the real-time value of power, I got this:
http://i.stack.imgur.com/ibrVj.png

As you can see, I am trying to calculate P=Ic*Vce.

I hope I am not wrong with my wiring, but I suppose that the AVCVS is going to give me Vce and the ACCVS will give me Ic.

I also got the same result without the AVCVS:
http://i.stack.imgur.com/IvKRW.png

But, if you take a look at the results, it looks like the power consumed by the IGBT reaches 4-6 times the value of power at load??
There must be something wrong here...

[Ettore]

...But, when I turned to the IGBT to get the real-time value of power, I got this:
http://i.stack.imgur.com/ibrVj.png

As you can see, I am trying to calculate P=Ic*Vce.

That's wrong! What you are calculating here is the instantaneous power Pswitch = dV/dt * dI/dt while the output power at load is effectively P=VOUT*IL or VOUT^2/R1 that's the same.
Put in another way, you are comparing apples with oranges - which are good to make a fruit salad.

In order to make the two things comparable you must integrate the instantaneous input power.
From my calculation which I verified in Proteus the input power should be less than 200 Watt at 8KW output.

Please send your licence information to support@labcenter.com. So I can provide you with further support.