In order to solve the applicability problems of the back/forward sweep complex affine arithmetic based power flow(CAA-PF)algorithm to the weak-mesh distribution with multi-type of distributed generators(DGs)

based on the detailed calculation characteristics analysis of the back/forward sweep CAA-PF algorithm

the loop analysis based on path matrix is adopted. In terms of the limits of the affine arithmetic in describing the reactive power uncertainty characteristics of DG

an improved CAA-PF algorithm using two-step correction of the reactive power and voltage sensitivity matrices is developed. Tests on the modified distribution networks with different scales based on the IEEE 33-node system

PG&E 69-node system and a real 113-node system with multi-type DG interconnections validate the effectiveness and applicability of the proposed algorithm.