Method for determining a PV generation limit on low voltage feeders for evenly distributed PV and Load

摘要

This paper presents a novel method for assessing the maximum allowable PV generation on low voltage feeders. It identifies a relationship between load, total feeder impedance, terminal count and PV generation at which the upper voltage limit for the line is breached. Identifying such a relationship alleviates the need for Distribution Network Service Providers (DNSPs) to perform load flow calculations on a case by case basis. It also increases a DNSP's understanding of power flow in low voltage feeders and potentially enables them to develop improved strategies for managing PV on their networks. Using feeder models provided by a DNSP servicing the Australian city of Sydney's Greater West region, a substantial number of load flow calculations were performed for wide variations in feeder impedance, load and PV generation. The PV generation range is chosen such that a breach of the upper voltage limit occurs on the line. The feeder voltage profile from these simulations are analysed in Matlab to determine PV generation limits. For evenly distributed PV and load, results show a linear relationship between this PV generation limit and load for a given terminal count and a second relationship between the PV generation limit and terminal count. It is then demonstrated that through the combination of these two relationships the PV generation limit can be determined for a given load, terminal count and total feeder impedance.