Improving Hosting Capacity of Unbalanced Distribution Networks via Battery Energy Storage Systems

Australia has large uptake of solar photovoltaics (PVs) and the major installations are rooftop PV systems in low voltage distribution networks (LVDNs). However, voltage rises and phase unbalance significantly limit PV hosting capacity of the LVDNs. To solve these issues and improve the hosting capacity, battery energy storage systems (BESSs) can provide ancillary services for the power systems. With a virtual synchronous generator capability, BESSs can provide voltage regulation and load balance services to alleviate the above issues, which in turn improves the hosting capacity. Thus, this paper proposes a BESS optimal allocation approach considering uncertainties from PV generation and load demand to improve the hosting capacity of the unbalanced LVDNs. The proposed approach is simulated with a real LVDN in Australia and results show that by allocating BESSs in the optimal location, the hosting capacity of the LVDN can be significantly improved and the phase unbalance can also be mitigated.