AC-DC-AC Circuit Design

[dharrington86]

Hi all,

I am currently a studying Electrical Engineering and for my final year project I am studying the way in which an electrical tram works (light rail system). These systems distribute electricity in DC and convert it to AC on the tram to feed the motors.
For this project i will need to build a circuit using a software package (PSpice, Yenka or something similar), i will also be building a physical model once i have a working version figured out using a software package. My degree so far has been largely based on electric Power systems rather than electronics. i was wondering if anybody could advise me on a three phase converter system that i could build to change an three phase AC input to DC and then back to AC again. I have been trying it with IGBT's and diodes but with little luck. Any help would be greatly appreciated.

Thanks in advance
Derek

[I_Daniel]

Sorry I cant help but I have a problem
AC-DC-AC. This appears to be a waste.
Ac to DC; what is the efficiency of the conversion ?
Then DC back to AC. Again what is the efficiency ?
What would the final efficiency be 40 - 60% ?

The losses, to me, makes this a very inefficient approach.

Why not just AC and then triac or SCR (thyristor) control.

All I can suggest is to look at how it is done on the Trams, Electric trains or Diesel/Electric locomotives.