Hello, I have a question regarding equations (2) and (3) in the attached picture. I am not sure equation (3) is correct. But *sj* is the power injection and *f{i,j}* is the power flow. I am a littel bit confused, how should I calculate y*{j,k} and *Yjk* in Matpower? According to the attached picture y*{j,k} is line adminance vector and Yjk bus adminance matrix. How can I calculate them from Ybus? Thank you, Naime