Abstract:With the increasing penetration of renewable energy, the diversification of load types, and the advancement of power electronics technology, traditional AC distribution networks are gradually evolving into hybrid AC/DC distribution networks. To address the challenge of power flow convergence in complex hybrid networks with multiple converters-particularly the instability arising from improper initial value selection-a unified power flow calculation method for hybrid AC/DC distribution networks incorporating incomplete LU decomposition preconditioning is proposed. Initially, the voltage and power equations for both the AC and DC sides of the voltage source converter (VSC) are established. Subsequently, power balance equations are formulated, taking into account various node types and the active/reactive power control strategies of the VSC. Jacobian matrix is then preconditioned using inoomplete LU decomposition, and the power flow of the hybrid AC/DC distribution network is solved via the preconditioned biconjugate gradient stabilized (BiCGSTAB) method. Finally, the effectiveness of the proposed preconditioning approach is verified through a comparison of non-zero element fill-ins and the number of iterations required for convergence. Furthermore, the robustness of the algorithm is validated by comparing its convergence behavior against alternative numerical methods.