Abstract
The UK government has set a target to achieve net-zero carbon emissions by 2050. Major countries in the world have set similar targets to achieve net-zero carbon emissions. The electrification of transport is essential for achieving this target. According to a report published by the EU, transforming petrol or diesel vehicle into electric vehicles (EVs) will account for 80% of the carbon emission reductions until 2050. However, the increase of EVs bring about several challenges: 1) increasing EVs causes grid problems such as network overloads and low voltages. Uncoordinated EV charging, in particular, causes those acute problems, resulting in potentially significant network reinforcement costs for distribution network operators (DNOs) and the need for urgent solutions. 2) the handling of retired batteries from EVs will eventually become a mass-scale problem, which requires environmentally friendly, low-cost solutions. At present, retired batteries are directly broken down, with valuable materials recycled. However, considering the remaining potential of the retired batteries, direct recycling of retired EV batteries compromises the batteries’ life-cycle economy and is not environmentally friendly.This thesis aims to tackle the above two problems: network congestions caused by EVs and the handling of retired EV batteries. In light of this, this thesis makes the following original contributions:
1) For the use case of airport service electric vehicles (ASEVs), a new dynamic ASEV behaviour model is developed, alongside an optimal control method based on a customised rollout approach to optimally control the ASEVs, with the aim to minimise energy costs whilst meeting airport business needs (luggage transport).
2) A novel business model is developed that controls second-life batteries (SLBs) retired from EVs to both perform energy arbitrage and provide flexibility services, where any profit is shared among the battery processer and EV customers who sent in the SLBs.
The profit sharing is performed through monthly payments from the battery processer to the EV customers, thus circumventing the difficulty in forecasting SLB remaining life and performance at the beginning of their second life.
3) A novel electric bus charging station model with the SLB energy storage system is proposed. The SLB energy storage system can reduce the charge demand during the peak time, which reduces the energy purchased cost for EB charging station and help support the network during peak time. Furthermore, the SLB energy storage system will provide flexibility services for DNOs. It will significantly reduce the network congestions and the reinforcement investments of the network.
The above work facilitates the EV connections to the grid by making the EV charging behaviour friendly to the grid, improves the application of SLBs by proposing a potential beneficial business model, and increases both the energy and economic efficiency by adopting SLBs to support EV charging and the grid. Ultimately, these innovations will contribute to achieving the net zero carbon emissions target by 2050.
| Date of Award | 22 Jun 2022 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Kang Ma (Supervisor) & Chenghong Gu (Supervisor) |