# Electric railway simulation

Discussion in 'Homework Help' started by Jess_88, Jul 13, 2014.

1. ### Jess_88 Thread Starter Member

Apr 29, 2011
174
1
Hey,

So I'v been working on my final year project for electrical engineering and my topic is electric railway (ER) systems. I'm simulating a newer model train (EMU) on a train line in Perth Western Australia in MATLAB. I am coming close to the finishing the simulation...just having some difficulty coming up with a power conditioning system for the EMU motors.

Here is my stuff so far:

The red blocks are the EMUs, the orange blocks are measurement and control sub systems for turning on the EMU loads as they move away from the supply. The blue blocks are the traction line equivalent impedance.

This is the subsystem blocks for the B-series EMU

Here is my issues
(1) I don't know how to make a load that draws current
(2) Using IGBT inverters seems unnecessarily complex for my simulation. Could I use a uncontrolled type inverter?
(3) I am having some serious difficulty trying to calculate and imagine the waveform as it goes through the conditioning stages. From what I understand, with the given system. it should be a positive cycle full wave after the four quadrant rectifier then smoothed to DC, then converted to 3 phased AC...

What do you think?

2. ### Turbo89 New Member

Jul 25, 2014
5
0
I'm not going to pretend I'm an expert in this, but I think I can help a little bit (based on real-life experience).

I may be way off base from what you're asking, but let's see.

First, to it sounds to me like the load should be the motors, at rated power and rated speed (maybe you want to simulate over a range of loads).

As for IGBT's, your talking about current levels that are usually supplied via IGBTs... so this would be my default option for hardware.

The flow of power from the source (2500 kv, 50hz) needs to be rectified to a DC (I'm thinking a simple diode bridge will work), then it clearly needs to be bucked down, then it needs to be put on a regulated DC bus. The regulated DC bus (and the whole drive system) will need to operated by a controller which pulse width modulates, generating an approximate sine wave at the voltage / frequency you're looking for (1225 V, 60 Hz at rated).

Hopefully this helps, let me know if you need clarification on any items.

3. ### donpetru Active Member

Nov 14, 2008
186
25
Motor rated power 145 kW ???
For example, in Romania, 060EA locomotive has 5100kW and contains six engines, each with: 850kW - 770Vdc.
And another thing: some locomotive models from Romania have been upgraded with static frequency converters, but the whole theory to introduce here is very bushy and require very much time to do this.