Power Flow in PME Distribution Systems During an Open Neutral Condition

The open neutral condition, in distribution networks, can cause significant damage to customer installations. Due to this, the continuity of the neutral conductor is important to the power utilities. In this paper, a power flow algorithm for three-phase four-wire distribution networks with protective multiple earthing (PME), during an open neutral condition, is presented. This algorithm is based on a modified backwards-forwards technique. Additionally, the return current flow is explicitly modeled. Results from three different distribution feeders with different load un-balance and topology are presented and discussed. Furthermore, the effects of the grounding resistances, the load model (constant admittance or constant power), and the neutral breakage point (abruption point) on the voltage levels, are investigated.