It all depends on how accurate and for what application you would like to model a distribution systems. I think for most of the applications, a simple RL  feeder would suffice. However, you should remember that it all depends on what kinds of studies you are going to perform. 

For more information you can find some examples in Matlab Simulunk Demos 

Kindly, check the Simpower Syetem toolbox examples. you will find alot and different kinds of simulations.

Thanks Dr Mohammadpour for your nice answer..

Thank u Mr Elgenedy.. I am searching the best model which it can simulate the distribution system with regard to it's specific challenges. As you know most of the simulink models (for lines or networks) are suitable for simulating the transmission lines not Distribution lines...

In that case I guess Simulink will not be a good choice. My friends in power system field usually use ETAP. you can give it a look.

Dear Ms Bagheri Tolabi,

I think there is no problem in analyzing a radial distribution network (e.g. Load Flow Analysis) using Simulink. You just need to draw its schematic and determine the input parameters (e.g. R and X of feeders, DGs, Substations, etc.) the same as what we do for transmission networks.

As far as I know, the Simulink is useful for academic case studies and thus for practical purposes, DigSILENT can be helpful.

Regards,

Morteza Shabanzadeh

http://mortezash.blogfa.com/

Matlab Simulink just only provide you the base about how to do your job apart from that best choice is ETAP.

I think ETAP is more easy and practical than MATLAB/Simulink. ETAP will help you to do this with high accuracy. I used both them and find that ETAP results were more accurate.

Thank u Mr Shabanzade, Mr Khalaf, and Mr Baig..I think your answers are helpful.. After reading all comments by now, I think Matlab Simulink environment should be upgraded in  electrical distribution network's simulation aspect.. I look forward to upgrade the software in the future so that the  distribution system's researchers and engineers can achieve a more accurate simulations & results in this area ..

Also I hope other researchers  to express their experiences in this field..

Please note that I mean a simulink model for "radial" distribution systems..

Thanks Mr Hedayatpor, So which software is more suitable for distribution system simulation in your opinion?

Hello,

Usually cable are used in the power distribution systems. Unlike overhead lines, cables have high capacitance, and their X/R ratios are lower. In addition, the lengths of the cables are significantly short in comparison with transmission, and subtransmission circuits. Therefore, the pi-model is suitable for representing power distribution cables, while the lumped series impedance model is adequate for representing overhead distribution lines.

You may read the following article for relevant knowledge about the differences between cables, and overhead lines as well as differences between HVAC, and HVDC lines.

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