I don’t understand approach (1). I don’t know why you say that DC power flow
implies you don’t have to keep track of islanding. How does the AC or DC power
flow make a difference here?
Ray
> On Mar 20, 2015, at 6:08 AM, Bijay Hughes <[email protected]> wrote:
>
> Hej all,
>
> I am modeling blackout in the US transmission lines system, and have two
> approaches to do so. I do it with DC power flow, which means I don't need to
> take care of islanding if I don't want to (although I am aware that I need to
> take care of isolated buses for convergence reasons). I have two approaches
> to do so: (1) do cascading failure simulation on whole system each iteration,
> whereby one doesn't keep track of islands; (2) do cascading failure
> simulation on the whole system to begin, see if islands are formed, and run
> the same simulation on each of these islands, and repeat the process
> exhaustively. In both cases, the powerflow converges as it is DC flow.
> However, the results are not matching, and I am wondering why. Could it be
> because of the difference in the number of slack buses? Because in my
> approach (1) the system will only have one slack bus in each iteration,
> however in my approach (2) the system will have multiple slack buses as the
> matpower chooses slack buses for each island automatically, thereby my system
> as a whole will have multiple slack buses. Is this the only reason? Which
> approach is better, (1) or (2)?
>
> Best,
>
> BH
