Quantifying and managing the impact of electric vehicles on power distribution assets
Date of Award
Edith Cowan University
Doctor of Philosophy
School of Engineering
Concern over the transportation sector’s greenhouse gas (GHG) emissions, which make up around 23% of all energy-related CO2 emissions, has grown in recent years. The widespread use of electric vehicles will be the primary strategy for tackling this issue. About 30% of the world’s passenger vehicle fleet is anticipated to be electrified by the year 2040. Moreover, the existing power distribution assets are already operating near their nominal capacities, and most of them have been in service for more than 25 years. Replacement of these assets will be very costly and disruptive to the power distribution network. Ergo, the main challenge with high penetration levels of electric vehicles (EVs) will be the ability of the existing power grid to support the extra unpredictable charging load from EVs without jeopardising the power supply and quality of power. The main bottleneck in integrating EVs into the grid is due to the limitation of the maximum operating temperature of the transformer. Hence, this research proposes a new Time of Use (ToU) pricing mechanism based on the transformers’ thermal loading is proposed. Battery energy storage systems (BESS), which serve as a buffer between supply and demand, present an opportunity to find a solution to this problem. Therefore, the purpose of this research is also to provide a novel technique for optimally sizing BESS systems based on the thermal loading of transformers. This research also explores challenges related to high penetration levels of rooftop photovoltaics (PVs), assessing the synergy between electric vehicle charging load and battery energy storage systems (BESS). Finally, this study investigates and proposes a solution to harmonic distortions. It is proposed that the demand-side control processes as a whole also take into account the impact of harmonics produced by nonlinear loads. Extensive simulation findings demonstrate that, even under harmonics injection by EVs, with the suggested demand response technique with a new ToU price signal based on the thermal loading of transformers, the accelerated ageing of distribution transformers may be significantly decreased without the need for additional grid infrastructure. Overall, in this research, the impacts of high penetration levels of EVs on power distribution assets have been investigated and a solution is proposed to minimise their negative impact.
Access to this thesis is embargoed until 28th July, 2024
Pradhan, P. (2023). Quantifying and managing the impact of electric vehicles on power distribution assets. Edith Cowan University. http://dx.doi.org/10.25958/r73q-rn05