Project Description

EPSRC Project code: EP/L001063/1
自然基金委 NSFC project code: NSFC51361130153 (智能电网与电动汽车环境友好集成与交互基础理论和关键技术研究（Intelligent Grid Interfaced Vehicle Eco‐charging (iGIVE))

The UK government is determined to address the challenges of tackling climate change and maintaining energy security in a way that minimises costs and maximises benefits to the economy. Among all sources of CO2 emissions in the UK, the energy supply accounts for about 40%, followed by the transport for over 25%, and emissions from cars and vans account for 70% in domestic transport sector. To meet the target of cutting greenhouse gas emissions by 80% by 2050, large proportion of electricity generated from low carbon sources integrated with mass adoption of electric vehicles (EV) offer a great potential. In its Energy Reform White Paper in 2011, the UK government noted the need for investment of more than £110 billion in the UK’s electricity transmission and generation by 2020 and its renewable energy roadmap highlighted that energy from wind, biomass and heat pumps are the leading contributors, including offshore wind. And the Committee on Climate Change recommended a target of 1.7 million EVs by 2020, as a step towards the UK's long term emissions reduction targets.

Likewise, the Chinese 12th National Economic and Social Development Five-Year Plan has set the target of 3.5% reduction per unit of GDP in both energy use and carbon dioxide emissions, and identified new energy and new energy vehicles among the seven priority industries in the next five years from 2012. To build a strong grid, an estimated 4 trillion RMB (about US $620 billion) will be invested, and for wind power, China National Energy Administration has proposed a target of 150 GW by 2020. In new energy vehicles, it focuses on plug-in hybrid electric vehicles (PHEV), battery electric vehicles (BEV) and fuel-cell electric vehicles, and it aims to sell 500,000 plug-in EVs by 2015 and over 5 million EVs on the road by 2020.

It is clear that both countries are fully committed to a planned ‘decarbonisation’ of their respective energy systems. However, both face the challenges of planning and building the suitable infrastructure, and of managing the resources to ensure future power systems operate more reliably, more flexibly, and more economically, by integrating and coordinating the actions of all temporally and spatially distributed actors of different natures, with due considerations to the constraints, and uncertainties imposed upon them by highly complex external environments

For power generation from renewable sources like wind and solar, the biggest challenge is their intermittent, variable and uncertain nature thus limiting their acceptance. According to the International Energy Agency, variable generation technologies such as wind and solar power will account for 37% of the net increase in generating capacity worldwide between 2009 and 2035. This however imposes significant challenges on the reliable and stable management of the electricity system based on conventional grid architecture and technologies. It has been widely researched that electric vehicles arguably could both benefit from and help to drive forward the development of smart grids where renewable resources are widely and substantially employed. This is because 1) EVs can be fully integrated into electricity load in smart grids using smart charging technology, shifting EV charging to off-peak period and thus flattening the load curve and significantly reducing generation and network investment needs. 2) They have the potential to be used as distributed large energy storage sources for the grid, thus enabling absorption of excess renewable energy production that would otherwise be wasted or curtailed during off-peak period and improving the economics of renewable energy generation. 3) Vehicle-to-grid (V2G), Vehicle-to-building (V2B) and other technologies, which feed the electricity stored in EV batteries back to the whole electric power system can provide regulation services such as frequency and voltage control, spinning reserves and peak-shaving capacity, thus reducing both the operational costs for existing plants and investment in building new electricity generation capacity.

A large number of researches have been carried out or are currently undergoing, investigating all aspects of integrating EVs to smart grid for better acceptance of intermittent renewable power. However, a number of technical challenges are still open for further exploitation. First, there is a lack of intelligent charging infrastructure which is potential a key inhibitor for the uptake of EVs. One key component is the provision of an efficient bi-directional on-board charger for rapid bi-directional power flow. Currently the on-board charging systems are single-phase and limited to slow domestic overnight charging, with no means for reverse-charging. In addition, the weight and cost of the charger are also key factors for market adoption. Secondly, there is a lack of a whole systems level intelligence on the entire fleet of EVs and their on-board batteries, making it hard to fully facilitate the fleet batteries as critical storage resources to the grid, which is operating close or exceeding the rated capacity both in the UK and in China. In general, charging patterns are uncertain, and are affected by a number of temporal and spatial factors relating to the timing, geographical location, density of the EVs demanding charging or providing ancillary services, the state of charge (SOC) and state of health (SOH) of the EV batteries. Unmanaged or improperly managed charging will significantly affect the reliable and stable operation of the grid, and lead to undesirable peak loads and the associated huge investments in peak generation. Improper design of charger (power converters) may inject large amount of harmonics and low-power factors to the grid, as well as significant electromagnetic interferences (EMI), which will not only impact adversely the electricity grid, but also exacerbate electromagnetic pollution in surrounding environment. Thus, this proposal envisions a fundamental bottom-up approach to widen the "technology bottlenecks" in on-broad charging equipment imposed by lack of understanding in traction machine drives, coupled with a top-down holistic approach to close the information gaps among all the key actors due a lack of intelligence at systems level. Our programme envisages that for successful widespread adoption of EVs to achieve the desirable decarbonisation of transport and to drive forward the development of smart grid integrating large amount of renewable power, the development of an ‘intelligent Grid Interfaced Vehicle Eco-charging (iGIVE) system’ that allows intelligent control of congestion-free bi-directional power flow and information flow is essential.
