Hey, thanks for your answers. Indeed the solution is the same if the tap ratios are set to 0 or 1 (as long as the SHIFTS are all 0), it was just an error on my part.
Ah, no callback for OPF? I just assumed that there was something similar to the callback functions in the CPF. Thanks for the links. Regards, Elis 2017-09-25 18:34 GMT+02:00 Abhyankar, Shrirang G. <[email protected]>: > > > Dear Matpower users, > > I have some questions about tap ratios in Matpwer. > > What does it mean if the tap ratios TAP are set to 0? > > Tap ratio=0 is used to indicate that the branch is a non-transformer > branch, while 1 indicates a transformer branch. Even if you set the tap > ratio = 0 for a transformer, MATPOWER internally uses a unity tap ratio > meaning a 1:1 voltage transformation. > > I have previously run some power flows without caring about the tap > ratios (TAP = 0). Now I set them to 1, and got quite different results. > > I don’t think this should happen. With 0 or 1, the power flow results > should be same. > > I can't see that the admittance matrix in Figure 3.1 in the manual is well > defined for zero tap ratio, so I thought setting them to 0 was like > deactivating them. > > Also, if I want to run an OPF with active tap changers, would it be best > to include the tap ratios directly in the optimization constraints or to > change the tap ratios in a callback function? Or maybe I can run several > OPFs and change the tap ratios manually between each? > > Incorporating tap changers in OPF is a non-trivial task. Moreover, I don’t > think there is a callback function in PF or OPF. > > Here are some relevant discussions from the mailing list. > > https://www.mail-archive.com/[email protected]/msg04162.html > > https://www.mail-archive.com/[email protected]/msg03339.html > > Note that there is a pending pull request for this feature. You can try > that out if you like. > > Shri > > > Regards, > Elis Nycander >
