Emma Arfa Grunditz

Performance Analysis of Current BEVs Based on a Comprehensive Review of Specifications

This paper aims to provide an analysis of battery electric vehicle (BEV) performance based on a comprehensive collection of specifications of over 40 currently globally available BEVs. The analysis comprises dimensional, powertrain, and performance data. The collected data are provided in this paper to facilitate further academic studies. There are a wide variety of BEVs from small to large as well as high-performance sedans and sport cars. It was found that all BEVs use Li-ion batteries with a specific energy of 55-170 Wh/kg and that battery weights represent 13%-37% of the vehicle weight. Furthermore, the majority of BEVs use permanent magnet motors, where some indicate power densities of 1.5-3.1 kW/kg. The specified New European Driving Cycle (NEDC) driving range varies between 85 and 528 km, and the energy consumption between 117 and 268 Wh/km. A rough estimation indicates that the powertrains share of the net energy consumption during NEDC may be up to around 40%-54%.

Electric machine design for traction applications considering recycling aspects-review and new solution

With the expansion of the fleet of electric and hybrid electric vehicles worldwide, it is of interest to consider recycling aspects of the parts that are introduced in these new vehicles. This paper focuses on the design of electrical machines considering recycling of its components. The materials to consider are mainly copper, core materials such as lamination steel or iron, and permanent magnets. One design is suggested with a core material of soft magnetic composites which is very suitable for recycling as it is a brittle material and thus simplifies the access of the copper winding. The suggested design shows to have similar performance to a similar size and similar weight commercial permanent magnet electric machine made with steel lamination.

Switched reluctance motor in electric or hybrid vehicle applications: A status review

Drive systems based on a switched reluctance motor (SRM) are important alternatives in traction applications because of the motor simple and robust structure without using rare-earth permanent magnets. In this paper, different aspects of the SRM-based drive systems for the vehicle traction are presented and reviewed. Motor design and comparison with the permanent magnet motors, power electronics, simulation, control, and thermal design of the drive are explained and discussed.

Characterizing BEV Powertrain Energy Consumption, Efficiency, and Range During Official and Drive Cycles From Gothenburg, Sweden

In this paper, the energy consumption per distance of a battery electric vehicle (BEV) is comprehensively investigated for various official and gathered real-world drive cycles, including the powertrains cycle average efficiency. The powertrain component losses are modeled with a high level of detail, and they are functions of both speed and load. It is shown that the difference in calculated drive-cycle energy consumption may be up to 16% when using two different acceleration approximation methods and one speed sample per second, which is an interval commonly used among drive cycles. In contrast to combustion engine vehicles (CEVs), BEV energy consumption per distance generally increases with increasing cycle speed levels, and time spent at high speed levels have the largest influence on the consumption. The effect of acceleration on energy consumption is seen to be considerably reduced due to regenerative braking as it reduces the consumption by up to 49% on an acceleration intense cycle. Even when the regenerative area is limited to about half, the decrease in driving range is less than 1% for most cycles. By introducing the concept of overconsumption, it is shown that much time spent at high levels of acceleration is one of the largest contributors to excess energy consumption for BEVs. Furthermore, the found cycle average powertrain efficiencies are quite similar between the different cycles, with 82%–90% during propulsion and only slightly lower during braking, i.e., much less speed dependent than for CEVs.

Three traction motors with different magnet materials — Influence on cost, losses, vehicle performance, energy use and environmental impact

The aim of reducing both cost and environmental impact of automotive electric traction motors motivates the examination of motor performance when using magnets of varying strength and materials. Such investigations have attracted increasing interest in recent years. Given the same take-off torque capability, three motors are compared that have the same stator geometry but different magnet materials in the rotor; two PMSMs — one with Nd(Dy)FeB and one with SmCo magnets — and one PMaSynRM with strontium-ferrite magnets. To compensate the weaker magnets, their corresponding core stacks are prolonged. The resulting torque capability at high speed levels is lower for the SmCo PMSM and ferrite PMaSynRM compared to the Nd(Dy)FeB PMSM. The ferrite PMaSynRM has the poorest dynamic vehicle performance, but also the lowest energy losses over a wide range of drive cycles. In addition, the ferrite based motor option has the lowest environmental impact during manufacturing as well as the lowest material cost estimate. The SmCo motor has slightly lower losses than the Nd(Dy)FeB, but the highest material cost. Certainly, the result signals that further in-depth studies of the described PMaSynRM are of high relevance.