Hosting Capacity of an Australian Low-Voltage Distribution Network for Electric Vehicle Adoption

Electric vehicle charging applies a notable strain on the electricity network due to the large load produced. This paper will examine these charging loads and their effect on the traditional electricity network using hosting capacity as a method to evaluate this impact. Two indices are proposed to quantitatively describe the hosting capacity. The voltage sag index describes the drop in voltage in the network due to normal loading and loading with electric vehicle charging. The substation power delivery index analyses the power flow through a substation as a ratio of its rated capacity to determine its utilisation and if it is overloaded. A case study of a distribution network in New South Wales, Australia was be performed to examine the current network capacities and peak loads. A futuristic prediction is made to evaluate how the network will cope with an increase in loads due to electric vehicle charging. Simulations were performed in a series of scenarios including no electric vehicle adoption, adopting electric vehicles as a second vehicles, one electric vehicle per household, and electric vehicle charging with rooftop solar panels. The results showed the network operating as expected and within acceptable limits when electric vehicle charging was not present. The introduction of charging increased voltage sag and power delivery to the point, as indicated by the indices, with some substations experiencing overloading and excessive voltage sag. These issues were mitigated by distributing electric vehicle charging throughout the day and introducing rooftop solar panels. The results of this study can be used to estimate the increase in network capacity required to accommodate for the increase in charging loads.