电动汽车不同加速方式的电能量消耗研究

针对电动汽车在不同加速方式下电能量消耗差异大的问题,研究了电动汽车按照不同加速方式进行加速时其单位里程能耗差异。推导了电动汽车加速过程中其单位里程能耗与车速、加速度之间的关系,分析了在多加速度与单加速度方式作用下其单位里程能耗的不同。以某款电动汽车为对象,对其不同加速方式下的电能量消耗进行了实车可行性实验。结果表明:与单加速度方式相比,电动汽车上凸型多加速方式的单位里程能耗较小,下凹型多加速方式的单位里程能耗较大。     

动力锂电池已经成为电动汽车性能对比的标杆

正目前已经商业化应用的锂电池正极材料包括钴酸锂、锰酸锂、磷酸铁锂和NCM(镍钴锰)三元材料等产品。国内电动汽车发展初期,动力电池由采用磷酸铁锂正极材料的电池主导,虽然这种正极材料制作的电池的循环寿命较好,但能量密度比较低,这就导致电动汽车的续航里程相对较短。"能量     

电动汽车的电池系统及储能应用

电动汽车电池系统的容量在0~100k Wh,与小型的分布式储能系统容量相当。在满足电动汽车行驶里程的情况下,适时地将电动汽车电池通过V2G或V2H模式应用于电力储能,可实现电动汽车电池的多功能用途,提升其附加价值。电动汽车电池退役以后,虽然容量衰减至80%以下,但大部分仍然有储能应用价值。通过评估、分级、成组等工序,将退役电动汽车电池制作成分布式储能系统,从而延长电动汽车电池的循环寿命。与电力储能相结合,充分做好电动汽车电池的梯次利用,既可以降低电动汽车电池的成本,又可以降低电力储能的成本。     

Extended-range electric vehicles and their lithium-ion batteries

增程式电动汽车(E-REV,extended-range electric vehicle),是指在纯电动汽车基础上,增加一个内燃发电机增程器(RE),给电池充电或直接驱动电机以增加续航里程,从而克服纯电动汽车续驶里程短的瓶颈的新型电动汽车.是介于传统混合动力汽车与纯电动汽车之间的车辆类型,在排放,噪音,系统复杂性等方面优于传统混合动力汽车,但又比纯电动汽车在续驶里程和成本方面更具优势,因此,E-REV更具大规模商业化应用推广价值.E-REV所携带的动力电池本身的续驶里程并不大,但它要求具备更高的效率,同时具备高能量密度与高功率密度,这势必给锂离子电池的发展带来新的挑战与机遇.本文简要介绍E-REV及其发展以及对我国新能源汽车发展的重要意义,在此基础上,重点对适合于E-REV的动力电池进行分析.     

基于LTC6804平台的电池管理系统设计

锂电池作为电动汽车能量源,需要几十甚至几百节电池以串联、并联组合来满足电动汽车爬坡、加速及续驶里程的需要,因此设计开发电池管理系统(BMS)至关重要。本文以STM32F103芯片为主控制器,以LTC6804芯片为单体电池电压采集芯片,以Labview平台为上位机设计了电动车用BMS,实现了对单体电池的电压,电流和温度的精准监测,实验结果表明本设计可靠性高,成本低,具有较高的实用价值。     

V2G or VEG?An investigation into the business model for future electric vehicles based on technological developments

基于目前电动汽车产业发展的困境认识,提出未来电动汽车技术发展与商业实现的VEG模式(Vehicle-Energy station-Grid).在VEG模式中,电动汽车充电方式由用户自己选择,可以在能量站快充,也可以在停车场或家庭车库进行慢充.能量站安装有低成本,长寿命的MW级储能电池,能够从电网充电储存电量后给电动汽车快速充电;同时,能量站能够与电网互动,用于电力调峰或调频.作者认为,开发低成本长寿命的新型储能电池和可以安全快速充电的新型动力电池是实现VEG模式的两大技术关键.只有这两大技术关键突破后,纯电动汽车产业发展的春天才能够真正到来.     

电动车底盘测功机续驶里程试验影响因素分析

介绍了依据GB/T 18386—2017《电动汽车能量消耗率和续驶里程试验方法》进行电动车续驶里程试验的流程,并对给各流程中续驶里程结果带来误差的因素进行分析,通过合理的试验方法确保试验结果的准确性。     

电动汽车的辅助动力及其显示系统

由于能源紧缺和环境污染严重，电动汽车是未来汽车的发展方向。我们研究的辅助动力电动汽车是通过辅助动力给电池充电，从而延长续驶里程。由于现在技术要求的限制和公共充电设施的缺乏，使辅助动力电动汽车的研究具有实际意义。     

电动汽车用光伏充电系统投资效益分析

介绍了光伏发电系统在电动汽车充电上的应用。根据最新的光伏补贴标准,针对家用电动汽车不同的日均行驶里程,对光伏充电系统和普通充电模式的成本及使用效益进行了分析。     

基于驾驶员驾驶习惯的增程式电动汽车参数匹配研究

纯电动汽车由于电池低能量密度导致续驶里程短,高价格导致用户购买力低,增程式电动汽车(EREV)通过增加增程器(发动机-发电机组)克服了这一缺陷,基于驾驶员的驾驶习惯分析了增程式电动汽车的性能,并对动力传动系统参数进行匹配,基于Cruise仿真软件对增程式电动汽车进行仿真分析,仿真表明,匹配的动力系统参数完全满足要求。     

Three dimensional energy profile:: A conceptual framework for assessing household energy use

The provision of adequate, reliable, and affordable energy has been considered as a cornerstone of development. More than one-third of the world's population has a very limited access to modern energy services and suffers from its various negative consequences. Researchers have been exploring various dimensions of household energy use in order to design strategies to provide secure access to modern energy services. However, despite more than three decades of effort, our understanding of household energy use patterns is very limited, particularly in the context of rural regions of the developing world. Through this paper, the past and the current trends in the field of energy analysis are investigated. The literature on rural energy and energy transition in developing world has been explored and the factors affecting households' decisions on energy use are listed. The and the factors affecting households' decisions on energy use are listed. The gaps identified in the literature on rural household energy analysis provide a basis for developing an alternative model that can create a more realistic view of household energy use. The three dimensional energy profile is presented as a new conceptual model for assessment of household energy use. This framework acts as a basis for building new theoretical and empirical models of rural household energy use.     

Are green hopes too rosy? Employment and welfare impacts of renewable energy promotion

In view of pressing unemployment problems, policy makers across all parties jump on the prospects of renewable energy promotion as a job creation engine which can boost economic well-being. Our analytical model shows that initial labor market rigidities in theory provide some scope for such a double dividend. However, the practical outcome of renewable energy promotion might be sobering. Our computable general equilibrium analysis of subsidized electricity production from renewable energy sources (RES-E) in Germany suggests that the prospects for employment and welfare gains are quite limited and hinge crucially on the level of the subsidy rate and the financing mechanism. If RES-E subsidies are financed by labor taxes, welfare and employment effects are strictly negative for a broad range of subsidy rates. The use of an electricity tax to fund RES-E subsidies generates minor benefits for small subsidy rates but these benefits quickly turn into significant losses as the subsidy rate exceeds some threshold value.     

Electric vehicle energy consumption modelling and estimation—A case study

Electric vehicles (EVs) have a limited driving range compared to conventional vehicles. Accurate estimation of EV's range is therefore a significant need to eliminate “range anxiety” that refers to drivers' fear of running out of energy while driving. However, the range estimators used in the currently available EVs are not sufficiently accurate. To overcome this issue, more accurate range estimation techniques are investigated. Nonetheless, an accurate power‐based EV energy consumption model is crucial to obtain a precise range estimation. This paper describes a study on EV energy consumption modelling. For this purpose, EV modelling is carried out using MATLAB/Simulink software based on a real EV in the market, the BMW i3. The EV model includes vehicle powertrain system and longitudinal vehicle dynamics. The powertrain is modelled using efficiency maps of the electric motor and the power electronics' data available for BMW i3. It also includes a transmission and a battery model (ie, Thevenin equivalent circuit model). A driver model is developed as well to control the vehicle's speed and to represent human driver's behaviour. In addition, a regenerative braking strategy, based on a series brake system, is developed to model the behaviour of a real braking controller. Auxiliary devices are also included in the EV model to improve energy consumption estimation accuracy as they can have a significant impact on that. The vehicle model is validated against published energy consumption values that demonstrates a satisfactory level of accuracy with 2% to 6% error between simulation and experimental results for Environmental Protection Agency and NEDC tests.     

Advanced photon-harvesting concepts for low-energy gap organic solar cells

Organic semiconductors usually show high absorption coefficients only over a limited spectral range. This has to be taken into account when designing organic solar cells with low-energy gap absorbers, as it is likely that these cells will have reduced harvesting abilities for photons of higher energy. We will present two routes to tackle this problem via luminescence and energy transfer and outline three novel concepts of how to integrate these mechanisms. We use an efficient low-energy gap organic solar cell based on zinc-phthalocyanine and fullerene C₆₀ as a model system.     

The potential for renewable energy in industrial applications

To date, insufficient attention has been paid to the potential of renewable energy resources in industrial applications. Our analysis suggests that up to 21% of final energy demand and feedstock-use in the manufacturing industry sector could be of renewable origin by 2050, a five-fold increase over current levels in absolute terms. This estimate is considerably higher than other recent global scenario studies. In addition, if a 50% share of renewables in power generation is assumed, the share of direct and indirect renewable energy use rises to 31% in 2050. Our analysis further suggests that bioenergy and biofeedstocks can constitute three-quarters of the direct renewables use in this sector by 2050. The remainder is roughly evenly divided between solar heating and heat pumps. The potential for solar cooling is considered to be limited.While low-temperature solar process heat can reach cost-effectiveness today in locations with good insolation, some bioenergy applications will require a CO₂ price even on the longer term. Biomass feedstock for synthetic organic materials will require a CO₂ price up to USD 100/t CO₂, or even more if embodied carbon is not considered properly in CO₂ accounts. Future fossil fuel prices and bioenergy prices in addition to the development of feedstock commodity markets for biomass will be critical. Decision makers are recommended to pay more attention to the potential for renewables in industry. Finally, we propose the development of a detailed technology roadmap to explore this potential further and discuss key issues that need to be elaborated in such a framework.     

Comparison of neural network,conditional demand analysis,and engineering approaches for modeling end-use energy consumption in the residential sector

This paper investigates the use of conditional demand analysis (CDA) method to model the residential end-use energy consumption at the national level. There are several studies where CDA was used to model energy consumption at the regional level; however the CDA method had not been used to model residential energy consumption at the national level. The prediction performance and the ability to characterize the residential end-use energy consumption of the CDA model are compared with those of a neural network (NN) and an engineering based model developed earlier. The comparison of the predictions of the models indicates that CDA is capable of accurately predicting the energy consumption in the residential sector as well as the other two models. The effects of socio-economic factors are estimated using the NN and the CDA models, where possible. Due to the limited number of variables the CDA model can accommodate, its capability to evaluate these effects is found to be lower than the NN model.     

Effects of climate and energy policy related measures and targets on the future structure of the European energy system in 2020 and beyond

Stabilising the concentration of CO₂ in the atmosphere at a level of 450 ppm in order to keep global temperature increase below 2 °C requires an ambitious climate policy. This study analyses the role of different technologies in the EU-27 with regard to efficiency improvements, fuel switching and energy saving measures under such a climate policy target. The analysis is carried out using the regionalised Pan-European TIMES energy system model, a technology oriented, linear optimisation model. Thereby limited resources and import potentials of various energy carriers, competition among different sectors and the country-specific differences in energy demand are taken into account. As a result, it turns out that the structure of energy use inside the EU-27 is much stronger, influenced by political targets and positions regarding climate protection, energy security and the use of nuclear energy than by available technologies. In the case of climate protection polices and limited use of nuclear energy, the most important measures for the reduction of greenhouse gases are an increased use of renewables, carbon capture and storage, fuel switching and the intensified application of electricity in the end use sectors. Efficiency improvements play an additional role when security of supply is taken into account.     

State-level benefits of energy efficiency

This paper describes benefits attributable to state-level energy efficiency programs. Nationwide, state-level energy efficiency programs have targeted all sectors of the economy and have employed a wide range of methods to promote energy efficiency. Standard residential and industrial programs typically identify between 20% and 30% energy savings in homes and plants, respectively. Over a 20-year period of time, an average state that aggressively pursues even a limited array of energy efficiency programs can potentially reduce total state energy use by as much as 20%. Well-designed energy efficiency programs can be expected to help overcome numerous barriers to the market penetration of energy efficient technologies and accelerate the market penetration of the technologies. Energy efficiency programs are cost-effective; typical benefit–cost ratios exceed 3:1 and are much higher when non-energy and macroeconomic benefits are included. Indeed, energy efficiency and associated programs and investments can create significant numbers of new jobs and enhance state tax revenues. Several states have incorporated energy efficiency into their economic development programs. It should also be noted that increasing amounts of venture capital are being invested in the energy sector in general and in specific technologies like solar power in particular.     

Innovation,low energy buildings and intermediaries in Europe: systematic case study review

As buildings throughout their life cycle account for circa 40% of total energy use in Europe, reducing energy use of the building stock is a key task. This task is, however, complicated by a range of factors, including slow renewal and renovation rates of buildings, multiple non-coordinated actors, conservative building practices and limited competence to innovate. Drawing from academic literature published during 2005–2015, this article carries out a systematic review of case studies on low energy innovations in the European residential building sector, analysing their drivers. Specific attention is paid to intermediary actors in facilitating innovation processes and creating new opportunities. The study finds that qualitative case study literature on low energy building innovation has been limited, particularly regarding the existing building stock. Environmental concerns, EU and national and local policies have been the key drivers; financial, knowledge and social sustainability and equity drivers have been of modest importance; while design, health and comfort and market drivers have played a minor role. Intermediary organisations and individuals have been important through five processes: (1) facilitating individual building projects, (2) creating niche markets, (3) implementing new practices in social housing stock, (4) supporting new business model creation and (5) facilitating building use post-construction. The intermediaries have included both public and private actors, while local authority agents have acted as intermediaries in several cases.     

The effect of completion strategy on fracture propagation from multiple cluster perforations in fossil hydrogen energy development

The hydraulic fracturing is extensively used to stimulate the production of fossil hydrogen energy. Perforation parameters have a great influence on the performance of hydraulically fractured horizontal wells in fossil hydrogen energy development. In this work, a practical model to study the effect of a completion scheme on simultaneous fracture propagation is proposed, in which the coupling fluid flow and stress interaction is considered, and a fracture propagation uniform index model is used to optimize the completion strategy. Moreover, this model is well validated by Wu's model and Zhang's model. The numerical study results indicate that a uniform completion scheme causes a non-uniform fracture development; an optimal completion method is proposed by reducing the cluster number, non-uniform spacing, and practical limited entry technique in a fracturing stage. Furthermore, the combined use of unequal cluster spacing and a limited entry strategy can significantly reduce the suppression effects between multiple clusters, improve the fluid flow into each cluster, and enhance the uniform propagation to achieve the maximum production. Our present work illustrates a better understanding of the effect of the completion strategy on the multiple fracture propagation, and paves a path for a more optimal completion design for fossil hydrogen energy development.