Small impedance branches on convergence of the Newton power flow in rectangular form

This paper investigates the process of Newton power flow in rectangular form when it is used for systems with small impedance branches, and finds out that the divergence only occurs in the cases which both ends of the small impedance branch are connected to PQ buses. The reason why the power flow diverges under this case and converges under other cases are explained by analyzing the iterative procedure of power flow. Experimental results validate the convergence analysis.