A modified holomorphic embedding method based hybrid AC-DC microgrid load flow

Abstract

Load flow study is a steady state analytical tool for power system network analysis where mostly iterative numerical methods are used to solve the load flow equations. But with the rise in complexity of the power networks due to amalgamation of both AC and DC power system within a network, the convergence time of these iterative load flow algorithms has been increased quite high. To resolve this problem a recursive load flow method has been developed called Holomorphic Embedding Load Flow Method (HELM) which reduces time complexity and also increase the probability of existence of the load flow solution. Here a new holomorphic embedding load flow problem formulation for a hybrid AC-DC microgrid system using line impedance values has been proposed. By using Padẽ approximant, we solve this holomorphic embedding load flow functions which guarantees the solution of load flow problem. Comparative study with well-known load flow methods over different test cases and a practical Indian distribution grid shows the efficiency and applicability of this method over the hybrid power networks.