Design and Analysis of Power and Transmission System of Downhole Pure Electric Command Vehicle

Electric vehicles use electric motors, which turn electrical energy into mechanical energy. As electric motors are conventionally used in all the industry, it is an established development site. It’s a mature technology with ideal power and torque curves for vehicular operation. Conventional vehicles use oil and gas as fuel or energy storage. Although they also have an excellent economic impact, the continuous use of oil and gas threatened the world’s reservation of total oil and gas. Also, they emit carbon dioxide and some toxic ingredients through the vehicle’s tailpipe, which causes the greenhouse effect and seriously impacts the environment. So, as an alternative, electric car refers to a green technology of decarbonization with zero emission of greenhouse gases through the tailpipe. So, they can remove the problem of greenhouse gas emissions and solve the world’s remaining non-renewable energy storage problem. Pure electric vehicles (PEV) can be applied in all spheres, but their special implementation can only be seen in downhole operations. They are used for low noise and less pollution in the downhole process. In this study, the basic structure of the pure electric command vehicle is studied, the main components of the command vehicle power system, namely the selection of the drive motor and the power battery, are analyzed, and the main parameters of the drive motor and the power battery are designed and calculated. The checking calculation results show that the power and transmission system developed in this paper meets the design requirements, and the design scheme is feasible and reasonable.

Optimum Driving System Design for Dual-Motor Pure Electric Vehicles

A pure electric vehicle driven by dual motors is taken as the research object and the driving scheme of the driving motor is improved to increase the transmission efficiency of existing electric vehicles.Based on the architecture of the transmission system,we propose vehicle performance parameters and performance indexes of a pure electric vehicle,a time-sharing driving strategy of dual motors.First,the parameters of the battery,motor,and transmission system are matched.Then,the electric vehicle transmission model is built in Amesim and the control strategy is designed in Simulink.With the optimization goal of improving the vehicle’s dynamic performance and driving range,the optimal parameters are determined through analysis.Finally,the characteristics of the motor are tested on the bench.The results show that the energy-saving potential of the timesharing driven double motor is higher,and the driving mileage of the double motor drive is increased by 4%.

Method of Electric Powertrain Matching for Battery-powered Electric Cars

The current match method of electric powertrain still makes use of longitudinal dynamics, which can’t realize maximum capacity for on-board energy storage unit and can’t reach lowest equivalent fuel consumption as well. Another match method focuses on improving available space considering reasonable layout of vehicle to enlarge rated energy capacity for on-board energy storage unit, which can keep the longitudinal dynamics performance almost unchanged but can’t reach lowest fuel consumption. Considering the characteristics of driving motor, method of electric powertrain matching utilizing conventional longitudinal dynamics for driving system and cut-and-try method for energy storage system is proposed for passenger cars converted from traditional ones. Through combining the utilization of vehicle space which contributes to the on-board energy amount, vehicle longitudinal performance requirements, vehicle equivalent fuel consumption level, passive safety requirements and maximum driving range requirement together, a comprehensive optimal match method of electric powertrain for battery-powered electric vehicle is raised. In simulation, the vehicle model and match method is built in Matlab/simulink, and the Environmental Protection Agency (EPA) Urban Dynamometer Driving Schedule (UDDS) is chosen as a test condition. The simulation results show that 2.62% of regenerative energy and 2% of energy storage efficiency are increased relative to the traditional method. The research conclusions provide theoretical and practical solutions for electric powertrain matching for modern battery-powered electric vehicles especially for those converted from traditional ones, and further enhance dynamics of electric vehicles.

Systematical Development of NVH Engineering for Vehicle Electrical Powertrain Based on an Optimized V-Model

For systematical NVH development of vehicle (especially for mass-production passenger vehicles) electric powertrain, an optimized V-Model is designed and has been implemented in the entire component-vehicle development, which integrates three individual branches: simulation, validation and optimization. Compared to the V-models in the traditional sense, this optimized V-model is not only driven by requirement and task accomplishment but also maximum optimization of NVH system performance. In this case, developing procedures are capable to be efficiently iterated and the NVH engineering can be expanded into 3D with this V-model.

OPTIMIZATION APPROACH FOR HYBRID ELECTRIC VEHICLE POWERTRAIN DESIGN

According to bench test results of fuel economy and engine emission for thereal power-train system of EQ7200HEV car. a 3-D performance map oriented quasi-linear model isdeveloped for the configuration of the powertrain components such as internal combustion engine,traction electric motor, transmission, main retarder and energy storage unit. A genetic algorithmbased on optimization procedure is proposed and applied for parametric optimization of the keycomponents by consideration of requirements of some driving cycles. Through comparison of numericalresults obtained by the genetic algorithm with those by traditional optimization methods, it isshown that the present approach is quite effective and efficient in emission reduction and fueleconomy for the design of the hybrid electric car powertrain.

Parameters matching and optimization of parallel hybrid electric vehicle powertrain

Aiming at the development of parallel hybrid electric vehicle （PHEV） powertrain, parameter matching and optimization are presented, According to the performance of PHEV, the optimization range of engine, motor, driveline gear ratio and battery parameters are determined. And then a two-level optimization problem is formulated based on analytical target cascading （ATC）. At the system level, the optimization of the whole vehicle fuel economy is carried out, while the tractive performance is defined as the constraints. The optimized parameters are cascaded to the subsystem as the optimization targets. At the subsystem level, the final drive and transmission design are optimized to make the ratios as close to the targets as possible. The optimization result shows that the fuel economy had improved significantly, while the tractive performance maintains the former level.

Implementation of Dynamic System Control Circuit Board Test System of Pure Electric Vehicles

The dynamic system control circuit board(DSCCB)is one of the most important components for dynamic system of pure electric vehicles. The current detection of the DSCCB is done manually, which is not only inefficient in the detection but also difficult to guarantee the data accuracy. In order to improve the detection efficiency and accuracy, a new testing system is designed by Labview. The total test time can be further reduced by about 75% compared with the results of the manual detection. In this paper, the three-parameter sine wave curve-fit algorithm theory is applied to the phase delay detection of the current sensor sampling circuit on the DSCCB. This method solves the problem of big error in the phase delay detection.

Toward More Electric Powertrains in Aircraft:Technical Challenges and Advancements

The main purpose of this article is to provide an instructive review of the technological challenges hindering the road toward more electric powertrains in aircraft.Hybrid,all-electric,and turboelectric powertrain architectures are discussed as possible fuel consumption and weight reduction solutions.Among these architectures,the short-term implementation of hybrid and all-electric architectures is limited,particularly for large-capacity aircraft due to the low energy/power density levels achievable by state-of-the-art electrical energy storage systems.Conversely,turboelectric architectures with advanced distributed propulsion and boundary layer ingestion are set to lead the efforts toward more electric powertrains.At the center of this transition,power converters and high-power density electric machines,i.e.,electric motors and generators,and their corresponding thermal management systems are analyzed as the key devices enabling the more electric powertrain.Moreover,to further increase the fuel efficiency and power density of the aircraft,the benefits and challenges of implementing higher voltage powertrains are described.Lastly,based on the findings collected in this article,the projected roadmap toward more electric aircraft powertrains is presented.Herein,the individual targets for each technology,i.e.,batteries,electric machines,and power converters,and how they translate to future aircraft prototypes are illustrated.

Calculation of the Losses of Series-Hybrid Powertrains

Regarding mobile machinery, particularly agricultural tractors, there is an ongoing competition for the most suitable technology to achieve optimum functionality with maximum efficiency. In this competition, the efficiency of electric series-hybrid powertrains （ESHPs） is often depicted as worse than the efficiency of mechanical-hydraulic power-split powertrains （MHPSPs）. On closer inspection of these statements, however, systematic errors, such as unequal balance limits, neglected size effects and nonlinearities, non-observance of recent technical developments and standards, or erroneous application of research results regarding MHPSPs on ESHPs are often evident. For verification （and under avoidance of the systematic errors mentioned above）, the losses of an ESHP of 150 kW power are for example calculated and compared with the losses of a typical MHPSP of the same power. The comparison of the losses shows that the ESHP clearly exceeds the efficiency of the comparative MHPSP in the main working range and that there is still potential for improvement.

Performance and Stability of Supercapacitor Modules based on Porous Carbon Electrodes in Hybrid Powertrain

Hybrid power sources have attracted much attention in the electric vehicle area. Particularly, electric-electric hybrid powertrain system consisting of supercapacitor modules and lithium-ion batteries has been widely applied because of the high power density of supercapacitors. In this study, we design a hybrid powertrain system containing two porous carbon electrode-based supercapacitor modules in parallel and one lithium ion battery pack. With the construction of the testing station, the performance and stability of the used supercapacitor modules are investigated in correlation with the structure of the supercapacitor and the nature of the electrode materials applied. It has been shown that the responding time for voltage vibration from 20 V to 48.5 V during charging or discharging process decreases from about 490 s to 94 s with the increase in applied current from 20 A to 100 A. The capacitance of the capacitor modules is nearly independent on the applied current. With the designed setup, the energy efficiency can reach as high as 0.99. The results described here provide a guidance for material selection of supercapacitors and optimized controlling strategy for hybrid power system applied in electric vehicles.

Multi-Criteria Decision Analysis for Usage Based Optimization of Powertrains

The electrification of powertrains leads to an increasing diversification of powertrain configurations. Each single configuration has its specific advantages which appear depending on the usage profile. To find the usage based optimal powertrain in consideration of a variety of evaluation criteria, the powertrains have to be optimized for the usage profile and characteristics have to be extracted from the usage profile. The carbon dioxide emissions of the optimized powertrains and usage based criteria are used in a multi-criteria decision analysis to determine the optimal powertrain for a specific usage profile. The description of characteristic maps forms the objective function of a minimization problem. The determined carbon dioxide emissions are one criterion in a multi-criteria decision process. All considered criteria are at least partly objective so that subjective ratings are eliminated as far as possible. The result is an optimized powertrain for a desired usage under the consideration of objective criteria that are extracted from the usage profile.

Parameters optimum matching of pure electric vehicle dual-mode coupling drive system

As an important development direction of pure electric vehicle drive system,the distributed drive system has the advantages of compact structure,high transmission efficiency,and flexible control,but there are some serious problems such as high performance requirements to the drive motors,complex control strategies,and poor reliability.To solve these problems,a two motors dual-mode coupling drive system has been developed at first,which not only has the capacity of two-speed gear shifting,but also can automatically switch between the distributed drive and the centralized drive by means of modes change control.So,the performance requirements to the drive motors can be reduced,the problem of abnormal running caused by the fault of unilateral distributed drive systems also can be resolved by replacing the drive mode with centralized drive.Then,the system parameters primary and the optimum matching under the principle of efficiency optimization have been carried out,which makes the drive system achieve predetermined functions and meet the actual demands of different operating statuses.At last,the economic comparison of a pure electric vehicle installation with a dual-mode coupling drive sytem,a single-motor centralized drive system or a dual-motor distributed drive system in the simulation conditions has been completed.Compared with other systems,the driving range of the electric vehicle driven by the designed system is significantly increased,which proves the better efficiency and application value of the system.

Review and Development of Electric Motor Systems and Electric Powertrains for New Energy Vehicles

This paper presents a review on the recent research and technical progress of electric motor systems and electric powertrains for new energy vehicles.Through the analysis and comparison of direct current motor,induction motor,and synchronous motor,it is found that permanent magnet synchronous motor has better overall performance;by comparison with converters with Si-based IGBTs,it is found converters with SiC MOSFETs show significantly higher efficiency and increase driving mileage per charge.In addition,the pros and cons of different control strategies and algorithms are demonstrated.Next,by comparing series,parallel,and power split hybrid powertrains,the series-parallel compound hybrid powertrains are found to provide better fuel economy.Different electric powertrains,hybrid powertrains,and range-extended electric systems are also detailed,and their advantages and disadvantages are described.Finally,the technology roadmap over the next 15 years is proposed regarding traction motor,power electronic converter and electric powertrain as well as the key materials and components at each time frame.

Robust control for electric vehicle powertrains

This paper considers the application of robust control methods(μ-and H∞-synthesis)to the speed and acceleration control problem encountered in electric vehicle powertrains.To this end,we consider a two degree of freedom control structure with a reference model.The underlying powertrain model is derived and combined into the corresponding interconnected system required forμ-and H∞-synthesis.The closed-loop performance of the resulting controllers are compared in a detailed simulation analysis that includes nonlinear effects.It is observed that theμ-controller offers performance advantages in particular for the acceleration control problem,but at the price of a high-order controller.

Route Towards Road Freight Electrification in India:Examining Battery Electric Truck Powertrain and Energy Consumption

Medium-duty/heavy-duty trucks(MD/HDTs)are yet to be included in India’s electric mobility plans.With the improvement of electric vehicle(EV)technologies,there is a growing interest in battery-electric trucks(BETs)from original equipment manufacturers(OEMs).The time is opportune to consider electrification as a future direction for road freight in India.Accordingly,this article presents the results of an energy consumption simulation study of a BET under Indian conditions.This study specifically considered an MDBET over a domestic drive cycle.These energy consumption figures can facilitate future studies that analyze the technical and practical feasibility of BETs in the country.In addition,the article provides the requisite groundwork for BET modeling for a simulation study by reviewing available EV powertrain systems and components.Appropriate powertrain considerations are thereby obtained for a typical medium-duty/heavy-duty battery-electric truck(MD/HDBET)in the Indian context.

Evaluation of Waste Heat Recovery of Electrical Powertrain with Electro-thermally Coupled Models for Electric Vehicle Applications

The mile range of an electric vehicle(EV)may be reduced significantly in cold weather owing to the energy demand for meeting thermal comfort in the vehicle cabin,as waste heat from a combustion engine is not available for this purpose.Various heat pump-based heating,ventilation,and air conditioning(HVAC)systems can be employed to absorb the heat energy from the surroundings and/or the waste heat from the electrical powertrain to facilitate cabin thermal comfort,thereby extending the EV mile range.However,there is a lack of research on the electro-thermally coupled modelling and evaluation of the thermal performance of HVAC systems.This paper proposes electro-thermally coupled models for the electrical machine and inverter by modelling the key electromagnetic quantities as functions of the torque and speed based on offline parameter extraction from two-dimensional electromagnetic finite element analysis.The proposed electro-thermally coupled models,which are computationally efficient,are integrated into HVAC thermofluid simulation.Comparative studies of three heat pump-based HVAC architectures(conventional ambient heat only,waste heat only,and dual heat source)are performed using the proposed electro-thermally coupled models.The dual heat source HVAC architecture exhibits superior thermal performance over its counterparts in cold weather conditions.

Powertrain Fuel Consumption Modeling and Benchmark Analysis of a Parallel P4 Hybrid Electric Vehicle Using Dynamic Programming

The goal of this work is to develop a hybrid electric vehicle model that is suitable for use in a dynamic programming algorithm that provides the benchmark for optimal control of the hybrid powertrain. The benchmark analysis employs dynamic programming by backward induction to determine the globally optimal solution by solving the energy management problem starting at the final timestep and proceeding backwards in time. This method requires the development of a backwards facing model that propagates the wheel speed of the vehicle for the given drive cycle through the driveline components to determine the operating points of the powertrain. Although dynamic programming only searches the solution space within the feasible regions of operation, the benchmarking model must be solved for every admissible state at every timestep leading to strict requirements for runtime and memory. The backward facing model employs the quasi-static assumption of powertrain operation to reduce the fidelity of the model to accommodate these requirements. Verification and validation testing of the dynamic programming algorithm is conducted to ensure successful operation of the algorithm and to assess the validity of the determined control policy against a high-fidelity forward-facing vehicle model with a percent difference of fuel consumption of 1.2%. The benchmark analysis is conducted over multiple drive cycles to determine the optimal control policy that provides a benchmark for real-time algorithm development and determines control trends that can be used to improve existing algorithms. The optimal combined charge sustaining fuel economy of the vehicle is determined by the dynamic programming algorithm to be 32.99 MPG, a 52.6% increase over the stock 3.6 L 2019 Chevrolet Blazer.

中国混合动力汽车动力总成技术进展

在国家政策与市场需求的双重驱动下,2021年以来,中国品牌混合动力汽车动力总成技术实现突破,围绕中国市场特点与消费者用车习惯推出一批具有中国特色、世界范围内领先的混合动力汽车产品。近期混合动力汽车市场销量呈爆发式增长,2023年中国市场混合动力乘用车销售超300万辆,同比增长83%。然而,受近年来汽车领域电动化浪潮影响,行业内尚存关于混合动力汽车仅为过渡性技术的观点,部分消费者对国产混动汽车技术产品力仍存质疑。为纠正对混合动力汽车的片面性、偏见性认识,该文围绕中国混合动力汽车动力总成技术路线展开,聚焦多样化的混动架构与专用化的核心部件,提出新的混合度定义作为动力总成电气化程度的统一评价标准,探讨国内外主流混动技术异同,剖析当下中国最前沿的混动技术特点与发展趋势,厘清中国混动汽车动力总成的发展脉络。研究表明:中国式混动汽车以大容量动力电池与插电式混合动力为技术特色,实现发动机、电机两大驱动动力源以及动力电池、增程系统两大动力能量源的灵活混合与优势互补。与纯内燃机车相比,得益于电驱动技术辅助,混合动力汽车聚焦提高发动机热效率、发动机高效区利用率以及整车燃油经济性。与纯电动车相比,混合动力汽车则基于发动机的增程发电,以高性价比和高便利度解决纯电动车的补能焦虑;并通过结合发动机直驱、变速器动力放大等机械驱动技术,以更低的硬件成本实现更稳定的强劲动力输出。混合动力汽车的独特优势使其作为长期性技术路线,将成为带动汽车产业向碳中和方向转型升级的关键,该文对当下市场的深度分析和未来趋势的理性推测将为中国混动技术的进一步发展提供有益参考。

纯电动和燃油公交车的火灾发展特性数值模拟研究

为了研究纯电动和燃油公交车火灾发展特性的异同,采用FDS数值模拟方法,考虑动力电池发生热失控喷射释放可燃气体并燃烧形成喷射火,对比电池包和燃油两类典型点火源下,公交车整车燃烧的热烟释放与火灾发展特性。结果表明:对于10.5 m长的纯电动和燃油公交车火灾,火灾增长速率均位于超快速火和快速火之间,在前500 s燃油公交车的热释放速率(Heat Release Rate,HRR)大于电动公交车,然而电动公交车HRR在500 s后大于燃油车;纯电动和燃油公交车峰值热释放速率(Peak Heat Release Rate,PHRR)分别为25.4 MW和24.2 MW,总热释放量(Total Heat Release,THR)分别为20.2 GJ和17.5 GJ,电动公交车相比燃油车具有更高的PHRR和THR,但PHRR达峰时间滞后144 s;在点火源距离后门较近和火灾前期100 s门窗均处于关闭状态最不利情况下,相比燃油公交车,电动车上部内饰的引燃时间提前、下部有所延迟,后天窗附近窗户破窗时间提前;在公交车火灾发展中,电动车窗户等开口部位处溢流火的高度大于燃油车,1 min内是人员逃生关键时间,且车厢内中后部温度均高于前部。

某纯电驱动重载车辆能耗预测模型

高精度能耗预测模型是准确预测车辆续驶里程的重要前提。针对载荷大幅度变化且非结构化道路运行的纯电驱动重载车辆,建立其组合能耗模型,该模型由能耗计算基本模型与长短时记忆(Long Short-Term Memory,LSTM)神经网络差值修正两部分组成。基于能量流动过程驱动电机和变速器效率建模,结合汽车行驶动力学建立能耗计算基本模型;采用LSTM神经网络来修正基本模型能耗预测结果与车辆典型工况功率测试值的差值,有效提高了大幅变载荷且低信噪比坡度环境下的车辆能耗预测精度,因此组合能耗模型具有参数简单和模型拟合不需解释能耗规律的优点。经试验测试分析,与VT-Micro能耗模型和径向基(Radial Basis Function,RBF)神经网络能耗模型相比,所提组合能耗模型的功率预测平均误差率分别降低了17.76%和3.35%,能够实现纯电驱动重载车辆复杂工况下能耗的准确实时预测。