An improved direct load flow approach for unbalanced active distribution networks with multiple voltage levels and configurations

With the increasing economic development, it is becoming more difficult for traditional distribution networks to meet new technical requirements, and as such the active distribution network has emerged. To obtain the statuses of active distribution networks accurately for reasonable planning and operation, it is necessary to address the load flow problem of three-phase unbalanced active distribution networks, with multiple voltage levels and high distributed generation (DG) penetrations. Therefore, this paper proposes an improved direct load flow approach that suits the load flow requirements of active unbalanced distribution networks of multiple voltage levels and network configurations. Through detailed numerical simulation and analyses, the computational performance of the proposed improved direct load flow approach has been tested in terms of feasibility, efficiency and robustness, with a promising application value