Improvement of Electric Vehicles Performance using Energy Storage Systems with High Specific Power

电气化动力系统已经获得了开发节能电动汽车（EV）的显著兴趣。储能系统（ESS）是实现更高续驶里程、更好爬坡或加速能力以及提高能源效率的核心。目前，电池广泛用于电动汽车，但为了获得可接受的行驶里程，具有高比能量（HSE）的电池通常是优选的，但它们的比功率通常较低（~ 1 kW/kg）。最近的趋势表明，具有潜力的新电池系统，如锂离子电容器或超级电容器（SC），已被开发为提供高比功率（HSP）（~ 12 kW/kg）。这些系统可以解决耦合在一起时主能量电池的快速退化的部分问题，并通过更有效地存储制动能量来增加行驶里程。它们的控制是一个双重挑战，因为它需要高性能转换器和智能管理。我的研究的长期愿景是开发高性能，可靠和具有成本效益的能源转换和运输ESS，以减少整体化石燃料的消耗。自2008年以来，我的研究一直集中在多ESS电动汽车（电池和SC）的真实的时间功率共享策略，以提高在驾驶循环结束时的整体性能。同时，我研究了可变电感器（VI）概念，以解决高功率传输中功率电感器的饱和问题，从而大大减少磁性材料，提高效率和功率密度。作为上述研究的加强，这项发现资助（DG）的总体目标是证明HSP-ESS通过改进的基于VI的功率转换器耦合，通过智能多目标能量管理算法正确协调，可以提高EV的整体效率和驾驶性能。为了实现这一目标，在扩展的跨学科挑战下，我将追求以下3个具体目标：1）分析HSP-ESS的能量效率，具体使用基于VI的转换器，包括它们的设计和实现; 2）研究增加HSP-ESS对ESS主要性能的影响，使用新定义的优点指标; 3）开发包含多个目标函数的算法，根据一些外生变量（交通、用户要求、天气条件等），对这些目标函数分配不同的重要程度，所提出的方法的新奇在于使用VI概念以便：1）开发更高效、更小和更轻的DC/DC转换器;以及2）定义多目标算法以更好地将HSP-ESS集成到EV中，以同时解决两个主要挑战：多ESS的能量管理和VI的控制复杂性。

Electrified powertrain systems have gained a significant interest to develop energy-efficient Electric Vehicles (EVs). Energy Storage System (ESS) is central to reach higher driving range, better climbing or acceleration capabilities, and increased energy efficiency. Currently, batteries are widely-used in EVs, but to obtain an acceptable driving range, batteries with High Specific Energy (HSE) are typically preferred but their specific power is normally low (~1kW/kg). Recent trends suggest that new battery systems with promising potential as Li-Ion capacitor or SuperCapacitors (SCs) have been developed to give High Specific Power (HSP) (~12kW/kg). These systems could address part of the fast degradation of the main energy battery when coupled together, and increase the driving range by storing the braking energy more efficiently. Their control is a double challenge because it demands a high performance converters and an intelligent management. The long-term vision of my research is to develop performant, reliable and cost-effective energy conversion and ESSs for transport that will reduce overall fossil fuel consumption. Since 2008, my research has focused on the real time power sharing strategies for a multi-ESS EVs (battery and SCs) for increasing the global performance at the end of the driving cycle. In parallel, I have studied the Variable Inductor (VI) concept to solve the saturation issues of power inductors for high power transfers showing a considerable reduction of magnetic material, with better efficiency and power density.As an enhancement of the aforementioned research, the general objective of this Discovery Grant (DG) is to demonstrate that HSP-ESSs coupled through improved VI-based power converters, correctly coordinated by an intelligent multi-objective energy management algorithm, may increase the global efficiency and the driving performance of EVs. To achieve this goal, under an extended interdisciplinary challenge, I will pursue the following 3 specific objectives: 1) to analyze the energy efficiency of HSP-ESS, with the specific usage of VI-based converters, including theirs design and implementation; 2) to study the impact on the main ESS performance with the addition of the HSP-ESSs, using a new defined indicator of merits; 3) to develop algorithms encompassing multiple objective functions to which different degrees of importance are assigned as a function of some exogenous variables (traffic, user requirements, weather conditions, etc.), to address the random nature of the power demand of the driving cycle.The novelty of the proposed approach is to use the VI concept in order: 1) to develop more efficient, smaller and lighter DC/DC converters; and 2) to define multi-objective algorithms to better integrate the HSP-ESSs into the EV to address simultaneously two main challenges: the energy management of multi-ESS and the control complexity of the VI.