Steady-state voltage stability / collapse Simulation

[countrytoad]

I am trying to understand how to do a steady-state voltage stability / collapse study using a simulation (in digsilent powerfactory, psse, pslf, psat, etc.). I understand that loads can be increased (or gens/lines out) until the system does not converge, indicating instability. Is there a basic standard process for this, or other steps to include?

 

[dpc]

I don't think the tweaking the model so that it fails to converge really tells you much about the physical system. I have had a lot of convergence issues trying to model systems that were doing just fine in the real world.

First step is to verify that your model is accurately representing real world data over all the conditions you have data for.

Then you can try step-load changes to see how the system responds.

 

[tlrols]

You can increase loads, or more likely increase transfers until the point of collapse is reached. The later is typically done on a regular basis to find voltage stability limits. When you are near the point of collapse you should monitor dv/dp and dv/dq to see how brittle the system is. Divergence may indicate a voltage stability problem, or it may be a data issue. If you are performing a proper PV study divergence should be an indicator of voltage collapse. You should also perform a QV analysis with any PV study...the two are needed to understand what is happening. If you are looking for a reference go here:

http://www.wecc.biz/committees/Stan...uments/WECC Voltage Stability Methodology.pdf