Help in modelling a Electric Distribution System

[jkai]

I am doing my final year project on the modelling of a dc zonal electric distribution system for a navy shipboard to analyse its stability.

I am planning to use Matlab for the modelling and similation. I have a few problems on the way ... I am not able to model a simple buck converter (Ship Service Converter Module) and ac-ac converter (Ship Service Inverter Module) Is it easier for me to model the whole system in other modelling software such as pspice or saber?

I am not sure on what sort of stability issue should i be looking at the system. Please advice.

Anyone has relevant information please forward to me. Really appreaciate the help. Thanks

 

[berkeman]

You don't need to do sub-cycle SPICE simulation of the DC-DC converter circuit in order to analyze its stability characteristics. You generally do that analysis in state space, and you also look at your phase margin (or gain margin) as you adjust your compensation of the feedback loop.

A good book to check out is "DC-DC Switching Regulator Analysys" by Daniel Mitchell. Another good book is "High-Frequency Switching Power Supplies" by George Chryssis.


EDIT -- BTW, you need to be aware that your state space analysis will vary based on what region of operation you are running in. For example, the order of the feedback changes in a buck DC-DC converter when the load lightens up to the point where you enter discontinuous operation. That makes things a little tricky, unless you are willing to waste power at light loads in a ballast (so you require some moderate minimum current level). Usually you don't want to waste that power, and so you have to do the full stability analysis including both continuous and discontinuous operation.