This paper presents a Newton's based method for the power flow on islanded microgrids including the effect of the primary control. The proposed method considers the variation of the frequency in the YBUS as well as the droop controls in the converters. Analytical and numerical considerations are presented in relation to the convergence of the algorithm. In particular, a numerical estimation of the Lipschitz constant is presented which is the main step in the demonstration of convergence by using the Kantorovitchs theorem. Although super-convergence is not completely demonstrated, numerical results performed in Matlab shown the efficiency of the method.