Novel load flow method for networks with multipoint-grounded-neutral and phase-to-neutral connected equipment

摘要

With the steady growth in distributed generation, more and more attention is paid to low voltage distribution networks. Many of these studies neglected the fact that most of the consumers and small generating units are phase-neutral connected in a multipoint-grounded neutral system at least in low voltage (LV) distribution systems that is common in Europe. If an equipment utilizes local regulation, it also detects this phase-to-neutral voltage. The effect of neutral can be substantial considering the narrow band of regulation and/or with equipment sensitive to neutral-earth voltage. Until now, the correct modelling of these kind of networks has been scarce; some of them face accuracy or convergence problems with these networks. This article presents an example for the problem and a new alternative calculation method to enable fast, simple-to-implement and accurate load flow calculation for unbalanced networks. Therefore, studies and control algorithms can rely on a more precise model.