An improved DC power flow model with virtual transmission channel for restoring energy internet power flow solvability

摘要

Large scale power grid is the most important foundation of energy internet. Due to the scale of energy internet increasingly expands with high complexity, using conventional power flow model cannot achieve reliable convergence in all cases. In order to avoid energy internet power flow insolvability, a new improved DC power flow model with virtual transmission channel is proposed in this paper. This model takes into account the active power loss of power grid to reduce the calculation error of standard DC power flow algorithm. The active power loss of each branch is simulated with equivalent loads located at both ends of the branch. An iterative algorithm is adopted to calculate the equivalent loads. In order to overcome power transmission congestion which is one of the main reasons leading to power flow insolvability, a virtual transmission channel model is presented. Virtual transmission channel is parallel to the related transmission line or transformer where the active power flow exceeds rated value. Some virtual transmission channels may be added to the original network during iteration process. Plenty of actual calculation examples show that the proposed improved DC power flow model is practical and effective. Using virtual transmission channel can significantly enhance the power transmission capacity, and helps to restore energy internet power flow solvability.