Electric and Hybrid Vehicles Collection
Share This Topical Collection
Editor
Prof. Dr. Kwok Tong Chau
Prof. Dr. Kwok Tong Chau
E-Mail
Website
Collection Editor
Department of Electrical and Electronic Engineering, The Hong Kong Polytechnic University, Hong Kong, China
Interests: electric vehicle technologies; renewable energy systems; machines and drives; power electronics
Special Issues, Collections and Topics in MDPI journals
Topical Collection Information
Dear Colleagues,
In a world where energy conservation, environmental protection and sustainable development are growing concerns, the development of electric vehicle (EV) and hybrid EV (HEV) technologies has taken on an accelerated pace. This collection entitled “Electric and Hybrid Vehicles” invites articles that address the state-of-the-art technologies and new developments for EVs and HEVs, including but not limited to energy sources, electric powertrains, hybrid powertrains, energy management systems, energy refueling systems, regenerative braking systems, system integration, system optimization and infrastructure. Articles which deal with the latest hot topics for EVs and HEVs are particularly encouraged such as advanced lithium-ion batteries, ultracapacitors, energy-efficient motor drives, bidirectional power converters, integrated-starter-generator systems, electric variable transmission systems, on-board renewable energy, inductive or wireless charging technology, and vehicle-to-grid technology. As the impact of the use of EVs and HEVs on our daily lives is utmost important, articles which deal with the relationships between the use of EVs or HEVs and the energy, environment and economy would be of particular interest.
Prof. Dr. K.T. Chau
Collection Editor
Manuscript Submission Information
Manuscripts for the topical collection can be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on this website. The topical collection considers regular research articles, short communications and review articles. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page.
Please visit the Instructions for Authors page before submitting a manuscript. The article processing charge (APC) for publication in this open access journal is 2600 CHF (Swiss francs).
Related Special Issues
Published Papers (168 papers)
Open AccessArticle
A Stochastic Methodology for EV Fast-Charging Load Curve Estimation Considering the Highway Traffic and User Behavior
by
Leonardo Nogueira Fontoura da Silva, Marcelo Bruno Capeletti, Alzenira da Rosa Abaide and Luciano Lopes Pfitscher
Cited by 6 | Viewed by 1312
Abstract
The theoretical impact of the electric vehicle (EV) market share growth has been widely discussed with regards to technical and socioeconomic aspects in recent years. However, the prospection of EV scenarios is a challenge, and the difficulty increases with the granularity of the
[...] Read more.
The theoretical impact of the electric vehicle (EV) market share growth has been widely discussed with regards to technical and socioeconomic aspects in recent years. However, the prospection of EV scenarios is a challenge, and the difficulty increases with the granularity of the study and the set of variables affected by user behavior and regional aspects. Moreover, the lack of a robust database to estimate fast-charging stations’ load curves, for example, affects the quality of planning, allocation, or grid impact studies. When this problem is evaluated on highways, the challenge increases due to the reduced number of trips related to the reduced number of charger units installed and the limited EVs range, which influence user anxiety. This paper presents a methodology to estimate the highway fast-charging station operation condition, considering regional and EV user aspects. The process is based in a block of traffic simulation, considering the traffic information and highway patterns composing the matrix solution model. Also, the output block estimates charging stations’ operational conditions, considering infrastructure scenarios and simulated traffic. A Monte Carlo simulation is presented to model entrance rates and charging times, considering the PDF of stochastic inputs. The results are shown for the aspects of load curve and queue length for one case study, and a sensibility study was conducted to evaluate the impact of model inputs.
Full article
►▼
Show Figures
Open AccessArticle
Substation Placement for Electric Road Systems
by
Niklas Jakobsson, Elias Hartvigsson, Maria Taljegard and Filip Johnsson
Cited by 3 | Viewed by 1769
Abstract
One option to avoid range issues for electrified heavy vehicles, and the large individual batteries for each such vehicle, is to construct electric road systems (ERS), where vehicles are supplied with electricity while driving. In this article, a model has been developed that
[...] Read more.
One option to avoid range issues for electrified heavy vehicles, and the large individual batteries for each such vehicle, is to construct electric road systems (ERS), where vehicles are supplied with electricity while driving. In this article, a model has been developed that calculates the cost for supplying an ERS with electricity from a regional grid to a road in the form of cables and substations, considering the power demand profile for heavy transport. The modeling accounts for electric losses and voltage drop in cables and transformers. We have used the model to exhaustively compute and compared the cost of different combinations of substation sizes and locations along the road, using a European highway in West Sweden as a case study. Our results show that the costs for building an electricity distribution system for an ERS vary only to a minor extent with the location of substations (10% difference between the cheapest cost and the average cost of all configurations). Furthermore, we have varied the peak and average power demand profile for the investigated highway to investigate the impact of a specific demand profile on the results. The results from this variation show that the sum of the peak power demand is the most important factor in system cost. Specifically, a 30% change in the peak power demand for the road has a significant impact on the electricity supply system cost. A reduction in the geographical variation of power demand along the road has no significant impact on the electricity distribution system cost as long as the aggregated peak power demand for all road segments is held constant. The results of the work are relevant as input to future work on comparing the cost–benefit of ERS with other alternatives when reducing CO
2 from road traffic—in particular from heavy road traffic.
Full article
►▼
Show Figures
Open AccessReview
Research on Oil Mist Leakage of Bearing in Hydropower Station: A Review
by
Jie Sun, Yuquan Zhang, Bin Liu, Xinfeng Ge, Yuan Zheng and Emmanuel Fernandez-Rodriguez
Cited by 4 | Viewed by 5592
Abstract
Hydropower is a clean and renewable energy, fundamental to the attainment of a sustainable society. Despite its efficacy and success, there is a need to address the hydroelectric stations’ oil throwing and mist leakage, resulting in the deterioration of the generating units, water,
[...] Read more.
Hydropower is a clean and renewable energy, fundamental to the attainment of a sustainable society. Despite its efficacy and success, there is a need to address the hydroelectric stations’ oil throwing and mist leakage, resulting in the deterioration of the generating units, water, and biodiversity. The conventional engineering measures to deal with oil mist leakage include: the reduction in the operating pad and oil temperature, optimization of the oil circulation loop in the oil tank, improvement of the sealing performance, and design of the oil mist emission device. However, the problem of oil mist leakage of bearings is complex, intractable, and cannot be solved by only one method. Numerical simulation can help to solve the oil mist problem and make up for the shortage of engineering measures. Yet, the mass transfer, involving multi-component and multi-phase flow, becomes a limitation for many numerical studies. As a result, this paper seeks to integrate the solutions by reviewing two influences: the global measures of oil mist leakage proof in the oil tank of bearings in the past 40 years, and the views and experiences of engineering practices. These findings offer some relevant insights into the effectiveness of the applied methods and solving of the oil mist leakage problem.
Full article
►▼
Show Figures
Open AccessArticle
A Real-Time Optimal Car-Following Power Management Strategy for Hybrid Electric Vehicles with ACC Systems
by
Xiaobo Sun, Weirong Liu, Mengfei Wen, Yue Wu, Heng Li, Jiahao Huang, Chao Hu and Zhiwu Huang
Cited by 2 | Viewed by 2746
Abstract
This paper develops a model predictive multi-objective control framework based on an adaptive cruise control (ACC) system to solve the energy allocation and battery state of charge (SOC) maintenance problems of hybrid electric vehicles in the car-following scenario. The proposed control framework is
[...] Read more.
This paper develops a model predictive multi-objective control framework based on an adaptive cruise control (ACC) system to solve the energy allocation and battery state of charge (SOC) maintenance problems of hybrid electric vehicles in the car-following scenario. The proposed control framework is composed of a car-following layer and an energy allocation layer. In the car-following layer, a multi-objective problem is solved to maintain safety and comfort, and the generated speed sequence in the prediction time domain is put forward to the energy allocation layer. In the energy allocation layer, an adaptive equivalent-factor-based consumption minimization strategy with the predicted velocity sequences is adopted to improve the engine efficiency and fuel economy. The equivalent factor reflects the extent of SOC variation, which is used to maintain the battery SOC level when optimizing the energy. The proposed controller is evaluated in the New York City Cycle (NYCC) driving cycle and the Urban Dynamometer Driving Schedule (UDDS) driving cycle, and the comparison results demonstrate the effectiveness of the proposed controller.
Full article
►▼
Show Figures
Open AccessArticle
Research on Starting Control Method of New-Energy Vehicle Based on State Machine
by
Yezhen Wu, Yuliang Xu, Jianwei Zhou, Zhen Wang and Haopeng Wang
Cited by 3 | Viewed by 2196
Abstract
In order to improve the starting smoothness of new-energy vehicles under multiple working conditions and meet the driving intention better, and to make the control strategy have high portability and integration, a starting control method for vehicle based on state machine is designed.
[...] Read more.
In order to improve the starting smoothness of new-energy vehicles under multiple working conditions and meet the driving intention better, and to make the control strategy have high portability and integration, a starting control method for vehicle based on state machine is designed. Based on inclination, starting of vehicle is divided into three working conditions: flat road, slight slope and steep slope. The method of vehicle starting control is designed, which includes five control states: default state control, torque pre-loading control, anti-rollback control, pedal control and PI (Proportion-Intergral) creep control. The simulation is carried out under the conditions of flat road, slight slope and steep slope. In terms of flat road and light slope, the vehicle travels below 3 km/h according to the driver’s intention, the speed is stable at 8 km/h during the creeping control phase and the jerk is lower than 5 m/s
3. In terms of steep slope, the speed is controlled at 0 km/h basically and the 10 s-rollback distance is less than 0.04 m. The results show that the strategy can fully meet the driver’s intention with lower jerk, better dynamic and stability, and the method can achieve the demand of new-energy vehicle starting control.
Full article
►▼
Show Figures
Open AccessArticle
Analysis of a Parallel Hybrid Electric Tractor for Agricultural Applications
by
Francesco Mocera and Aurelio Somà
Cited by 58 | Viewed by 6836
Abstract
The field of Non-Road Mobile Machineries (NRMM) is now more than ever considering the adoption of electric systems to reduce the amount of pollutant emissions per unit of work. However, the intensity and complexity of the tasks performed by a working machine during
[...] Read more.
The field of Non-Road Mobile Machineries (NRMM) is now more than ever considering the adoption of electric systems to reduce the amount of pollutant emissions per unit of work. However, the intensity and complexity of the tasks performed by a working machine during its life is an obstacle to the widespread adoption of electric systems. Specific design solutions are required to properly split the power output of the hybrid powertrain among the different loads (wheel, power take off, hydraulic tools, etc.). In this work, a performance analysis between a traditional agricultural tractor and a proposed hybrid electric architecture of the same vehicle is shown. The comparison was performed on a set of tasks characterized on a real orchard tractor which were used to build the input signals of two different numerical models: one for the traditional diesel architecture and the other for the hybrid electric solution. The two models were tested with the same operating tasks to have a one to one comparison of the two architectures. Peak power capabilities of the hybrid solution and performance of the Load Observer energy management strategy were investigated to validate the feasibility of the proposed solution.
Full article
►▼
Show Figures
Open AccessArticle
Operational Aspects of Electric Vehicles from Car-Sharing Systems
by
Katarzyna Turoń, Andrzej Kubik and Feng Chen
Cited by 24 | Viewed by 5352
Abstract
The article was dedicated to the topic of energy consumption of driving cars equipped with an electric motor. Due to the emerging demands for the excessive use of energy by vehicles (including car-sharing system vehicles), the authors carried out research to determine factors
[...] Read more.
The article was dedicated to the topic of energy consumption of driving cars equipped with an electric motor. Due to the emerging demands for the excessive use of energy by vehicles (including car-sharing system vehicles), the authors carried out research to determine factors that affect the energy consumption. Due to the occurrence of a research gap related to the lack of reliable scientific information regarding real electricity consumption by vehicles used in car-sharing systems, the authors attempted to determine these values based on the proposed research experiment. The purpose of the research was to identify factors that increase energy consumption while driving in the case of car-sharing systems and developing recommendations for users of car-sharing systems and system operators in relation to energy consumption. Based on data received from car-sharing system operators and to their demands that users move cars uneconomically and use too much energy, the authors performed a scientific experiment based on Hartley’s plan. The authors made journeys with electric cars from car-sharing (measurements) in order to compare real consumption with data obtained from operators. As a result, the authors developed a list of factors that negatively affect the energy consumption of electric vehicles from car-sharing systems. As conclusion, a number of recommendations were developed for car-sharing system operators on how to manage their systems to reduce excessive energy consumption in electric vehicles.
Full article
►▼
Show Figures
Open AccessArticle
Adaptive Rule-Based Energy Management Strategy for a Parallel HEV
by
Rishikesh Mahesh Bagwe, Andy Byerly, Euzeli Cipriano dos Santos, Jr. and Zina Ben-Miled
Cited by 34 | Viewed by 4014
Abstract
This paper proposes an Adaptive Rule-Based Energy Management Strategy (ARBS EMS) for a parallel hybrid electric vehicle (HEV). The aim of the strategy is to facilitate the aftermarket hybridization of medium- and heavy-duty vehicles. ARBS can be deployed online to optimize fuel consumption
[...] Read more.
This paper proposes an Adaptive Rule-Based Energy Management Strategy (ARBS EMS) for a parallel hybrid electric vehicle (HEV). The aim of the strategy is to facilitate the aftermarket hybridization of medium- and heavy-duty vehicles. ARBS can be deployed online to optimize fuel consumption without any detailed knowledge of the engine efficiency map of the vehicle or the entire duty cycle. The proposed strategy improves upon the established Preliminary Rule-Based Strategy (PRBS), which has been adopted in commercial vehicles, by dynamically adjusting the regions of operations of the engine and the motor. It prevents the engine from operating in highly inefficient regions while reducing the total equivalent fuel consumption of the vehicle. Using an HEV model developed in Simulink
®, both the proposed ARBS and the established PRBS strategies are compared over an extended duty cycle consisting of both urban and highway segments. The results show that ARBS can achieve high MPGe with different thresholds for the boundary between the motor region and the engine region. In contrast, PRBS can achieve high MPGe only if this boundary is carefully established from the engine efficiency map. This difference between the two strategies makes the ARBS particularly suitable for aftermarket hybridization where full knowledge of the engine efficiency map may not be available.
Full article
►▼
Show Figures
Open AccessArticle
Segmental Track Analysis in Dynamic Wireless Power Transfer
by
Shi-Chun Yang, Hong He, Xiao-Yu Yan, Yu-Hang Chen, Yang Hua, Yao-Guang Cao, Jun Li, Hong-Hai Li and Sheng Yin
Cited by 4 | Viewed by 2869
Abstract
Electric vehicles have gained more and more attention because of the serious oil crisis and environmental problems. However, the disadvantages of the electric vehicle, such as short driving range, high battery cost, and inconvenient charging, are hindering its market development and expansion. The
[...] Read more.
Electric vehicles have gained more and more attention because of the serious oil crisis and environmental problems. However, the disadvantages of the electric vehicle, such as short driving range, high battery cost, and inconvenient charging, are hindering its market development and expansion. The realization of on-road wireless power transfer technology can effectively solve the problems of short driving range, prevent the battery from being completely discharged to prolong its service life, and reduce requirement of on-board battery. In this paper, the charging mode and the compensation topology of wireless power transfer technology are discussed and then the equivalent circuit model of segmental wireless power transfer system is built. We carried out some magnetic field simulation to analyze how the track shape and length influence coupling coefficient, which is later verified by experiments.
Full article
►▼
Show Figures
Open AccessReview
Prediction of Electric Vehicle Range: A Comprehensive Review of Current Issues and Challenges
by
Bogdan Ovidiu Varga, Arsen Sagoian and Florin Mariasiu
Cited by 142 | Viewed by 18190
Abstract
Electric vehicles (EV) are the immediate solution to drastically reducing pollutant emissions from the transport sector. There is a continuing increase in the number of EVs in use, but their widespread and massive acceptance by automotive consumers is related to the performance they
[...] Read more.
Electric vehicles (EV) are the immediate solution to drastically reducing pollutant emissions from the transport sector. There is a continuing increase in the number of EVs in use, but their widespread and massive acceptance by automotive consumers is related to the performance they can deliver. The most important feature here (a hot topic at present in EV research) is related to the possibility of providing a more accurate prediction of range. Range prediction is a complex problem because it depends on a lot of influence factors (internal, external, constant, variables) and the present paper aims to investigate the effect of these factors on the range of EVs. The results and aspects of current worldwide research on this theme are presented through the analysis of the main classes of influence factors: Vehicle design, the driver and the environment. Further, the weight and effect of each potential factor which influences EV range was analyzed by presenting current issues. An exhaustive and comprehensive analysis has made it possible to identify future research and development directions in the EV research field, resulting in massive future and immediate EV penetration in the automotive market.
Full article
►▼
Show Figures
Open AccessArticle
Direct Driven Hydraulic Drive: Effect of Oil on Efficiency in Sub-Zero Conditions
by
Tatiana Minav, Jani Heikkinen, Thomas Schimmel and Matti Pietola
Cited by 14 | Viewed by 4813
Abstract
Direct driven hydraulic drives (DDH) have the advantages of compact high power density in hydraulic systems and flexible control of electric motors. These advantages can benefit non-road mobile machinery (NRMM) applications. However, maintaining high efficiency while working in sub-zero conditions with NRMM is
[...] Read more.
Direct driven hydraulic drives (DDH) have the advantages of compact high power density in hydraulic systems and flexible control of electric motors. These advantages can benefit non-road mobile machinery (NRMM) applications. However, maintaining high efficiency while working in sub-zero conditions with NRMM is challenging. Therefore, this paper investigates the effect of hydraulic oil on the efficiency of a DDH in a cold environment for an NRMM application. In the DDH setup, the speed and position control of a double-acting cylinder was implemented directly with an electric motor drive in a closed-loop system without the conventional control valves. Efficiency measurements of the DDH setup with two oils (conventional multi-grade and high-performance) were conducted under different operating conditions (speed and payload) and environmental conditions (temperature in °C). The paper provides an evaluation of the electro-hydraulic system and a discussion on the usage of hydraulic oil by non-road mobile working machines in sub-zero conditions. An experimental investigation demonstrated an improvement in efficiency of 5%-unit at 22 °C, from 2%-unit to 5%-unit at 3 °C, and of almost a 10%-unit at temperatures below zero (−10 °C) by changing oil.
Full article
►▼
Show Figures
Open AccessArticle
Research into an Efficient Energy Equalizer for Lithium-Ion Battery Packs
by
Hongrui Liu, Bo Li, Yixuan Guo, Chunfeng Du, Shilong Chen and Sizhao Lu
Cited by 1 | Viewed by 3123
Abstract
An efficient multi-mode energy equalizer for lithium-ion battery packs is proposed and energy balance strategies are studied in this paper. The energy balance strategies include the selection of the controlled object in the battery’s different working states and the current form of the
[...] Read more.
An efficient multi-mode energy equalizer for lithium-ion battery packs is proposed and energy balance strategies are studied in this paper. The energy balance strategies include the selection of the controlled object in the battery’s different working states and the current form of the controlled object. During the energy balancing process, the strongest single cell or the weakest single cell is selected as the controlled object according to the different working states of the battery, and the balanced current of the controlled object is continuous. Therefore, the energy equalizer proposed in this paper has a fast balancing speed, an improved balancing effect, and an excellent balancing reliability. According to the energy equalizer, the relevant experimental platform was built, and balance experiments in the battery’s different working states using a battery pack composed of four serially-connected lithium iron phosphate batteries were completed. Finally, the experimental results proved the effectiveness of the energy equalizer.
Full article
►▼
Show Figures
Open AccessArticle
Advanced Methodology for the Optimal Sizing of the Energy Storage System in a Hybrid Electric Refuse Collector Vehicle Using Real Routes
by
Ernest Cortez, Manuel Moreno-Eguilaz and Francisco Soriano
Cited by 7 | Viewed by 4145
Abstract
This paper presents a new methodology for optimal sizing of the energy storage system (
), with the aim of being used in the design process of a hybrid electric (HE) refuse collector vehicle (
). This
[...] Read more.
This paper presents a new methodology for optimal sizing of the energy storage system (
), with the aim of being used in the design process of a hybrid electric (HE) refuse collector vehicle (
). This methodology has, as the main element, to model a multi-objective optimisation problem that considers the specific energy of a basic cell of lithium polymer (
–
) battery and the cost of manufacture. Furthermore, optimal space solutions are determined from a multi-objective genetic algorithm that considers linear inequalities and limits in the decision variables. Subsequently, it is proposed to employ optimal space solutions for sizing the energy storage system, based on the energy required by the drive cycle of a conventional refuse collector vehicle. In addition, it is proposed to discard elements of optimal space solutions for sizing the energy storage system so as to achieve the highest fuel economy in the hybrid electric refuse collector vehicle design phase.
Full article
►▼
Show Figures
Open AccessArticle
Quantitative Comparison of Vernier Permanent-Magnet Motors with Interior Permanent-Magnet Motor for Hybrid Electric Vehicles
by
Christopher H. T. Lee, Matthew Angle, Krishan Kant Bhalla, Mohammad Qasim, Jie Mei, Sajjad Mohammadi, K. Lakshmi Varaha Iyer, Jasmin Jijina Sinkular and James L. Kirtley
Cited by 9 | Viewed by 5361
Abstract
In this paper, three Vernier permanent-magnet (VPM) motor, namely the inner-rotor VPM (IR-VPM) motor, the outer-rotor VPM (OR-VPM) motor and the OR consequent-pole VPM (OR-CP-VPM) motor are proposed for the hybrid electric vehicle (HEV) applications. Owing to employment of toroidal-winding arrangement, the OR-VPM
[...] Read more.
In this paper, three Vernier permanent-magnet (VPM) motor, namely the inner-rotor VPM (IR-VPM) motor, the outer-rotor VPM (OR-VPM) motor and the OR consequent-pole VPM (OR-CP-VPM) motor are proposed for the hybrid electric vehicle (HEV) applications. Owing to employment of toroidal-winding arrangement, the OR-VPM and the OR-CP-VPM motors can enjoy better material utilization and easier manufacturing process than its IR-VPM counterpart. Meanwhile the OR-CP-VPM motor can utilize the consequent-pole topology to minimize flux leakage that exists in conventional design. With the support of finite element method (FEM), the motor performances among the VPM motors and the profound interior permanent-magnet (IPM) motor can be compared quantitatively.
Full article
►▼
Show Figures
Open AccessArticle
Simulation of the Oxygen Reduction Reaction (ORR) Inside the Cathode Catalyst Layer (CCL) of Proton Exchange Membrane Fuel Cells Using the Kinetic Monte Carlo Method
by
Baosheng Bai and Yi-Tung Chen
Cited by 8 | Viewed by 5097
Abstract
In this paper, a numerical model of the kinetic Monte Carlo (KMC) method has been developed to study the oxygen reduction reaction (ORR) that occurs inside the cathode catalyst layer (CCL). Firstly, a 3-D model of the CCL that consists of Pt and
[...] Read more.
In this paper, a numerical model of the kinetic Monte Carlo (KMC) method has been developed to study the oxygen reduction reaction (ORR) that occurs inside the cathode catalyst layer (CCL). Firstly, a 3-D model of the CCL that consists of Pt and carbon spheres is built using the sphere packing method; secondly, an efficient procedure of the proton-oxygen reaction process is developed and simulated. In the proton-oxygen reaction process, all of the continuous movements of protons and oxygen are considered. The maximum reaction distance is determined to be 8 Å. The input pressures of protons and oxygen are represented by the number of spheres of the species. The value of the current density is calculated based on the amount of reaction during the interval time. Indications are that the results of the present model match reasonably well with the published results. A new way to apply the KMC method in the proton exchange membrane fuel cell (PEMFC) research field is developed in this paper.
Full article
►▼
Show Figures
Open AccessArticle
Steering Stability Control for a Four Hub-Motor Independent-Drive Electric Vehicle with Varying Adhesion Coefficient
by
Rufei Hou, Li Zhai and Tianmin Sun
Cited by 13 | Viewed by 4477
Abstract
In order to enhance the steering stability of a four hub-motor independent-drive electric vehicle (4MIDEV) on a road with varying adhesion coefficient, for example on a joint road, this paper proposes a hierarchical steering stability control strategy adapted to the road adhesion. The
[...] Read more.
In order to enhance the steering stability of a four hub-motor independent-drive electric vehicle (4MIDEV) on a road with varying adhesion coefficient, for example on a joint road, this paper proposes a hierarchical steering stability control strategy adapted to the road adhesion. The upper control level of the proposed strategy realizes the integrated control of the sideslip angle and yaw rate in the direct yaw moment control (DYC), where the influences of the road adhesion and sideslip angle are both studied by the fuzzy control. The lower control level employs a weight-based optimal torque distribution algorithm in which weight factors for each motor torque are designed to accommodate different adhesion of each wheel. The proposed stability control strategy was validated in a co-simulation of the Carsim and Matlab/Simulink platforms. The results of double-lane-change maneuver simulations under different conditions indicate that the proposed strategy can effectively achieve robustness to changes in the adhesion coefficient and improve the steering stability of the 4MIDEV.
Full article
►▼
Show Figures
Open AccessArticle
Analytical Calculation of Armature Reaction Field of the Interior Permanent Magnet Motor
by
Fangwu Ma, Hongbin Yin, Lulu Wei, Liang Wu and Cansong Gu
Cited by 19 | Viewed by 4209
Abstract
The energy crisis and environmental concerns worldwide have helped usher in the age of electric vehicles (EVs) and hybrid EVs (HEVs). The interior permanent magnet motors (IPMMs) are widely used in these vehicles. The analysis of the armature reaction field is the most
[...] Read more.
The energy crisis and environmental concerns worldwide have helped usher in the age of electric vehicles (EVs) and hybrid EVs (HEVs). The interior permanent magnet motors (IPMMs) are widely used in these vehicles. The analysis of the armature reaction field is the most critical issue in the study of IPMMs since it determines the characters of torque, efficiency, vibration, and the radiated acoustic noise. This paper provides a calculation method of the armature reaction magnetic field (ARMF) of an IPMM. First, the formulas of ARMF without magnetic barrier are derived. Second, the relative permeance function of an IPMM is calculated. Third, the analytical solution of the ARMF of an IPMM is derived by applying the armature reaction magnetic field with unsaturated rotor multiplied by relative permeance function. Finally, several results of comparisons between the calculation method proposed in this paper and the finite element method are presented. Based on the calculation method proposed in this paper, the magnetic barrier’s influence on the ARMF is studied. The spatial harmonic orders and time harmonic orders of the ARMF of IPMM are revealed respectively.
Full article
►▼
Show Figures
Open AccessArticle
Digital Control of an Interleaving Operated Buck-Boost Synchronous Converter Used in a Low-Cost Testing System for an Automotive Powertrain
by
Miran Rodič, Miro Milanovič and Mitja Truntič
Cited by 4 | Viewed by 4194
Abstract
Based on the standardization in the automotive industry, systems require extensive testing, which represents significant costs regarding personnel and equipment. The testing systems must be built in such a way that a bidirectional power flow is possible between the power source and the
[...] Read more.
Based on the standardization in the automotive industry, systems require extensive testing, which represents significant costs regarding personnel and equipment. The testing systems must be built in such a way that a bidirectional power flow is possible between the power source and the tested system. Additionally, applied testing systems have to possess high disturbance immunity. Classical current programmed control performed using an analogue approach suffers from low disturbance rejection during switching operation. The digital control of DC–DC converter can solve this problem with the use of digital integration in a measurement chain. The integrals of values are obtained by using a Voltage Control Oscillator (VCO) and appropriate counters. Digital control of an interleaving operated bidirectional buck-boost synchronous converter can be applied in the testing system for automotive powertrains. The voltage and current measurements with the application of an integral-measurement principle act as low-pass filters, which remove the disturbances from the measured values. The digital implementation of a compensation ramp (current mode control) and method for choice of control parameters are described. All the tasks for measurements, as well as current and voltage control, were implemented within the FPGA (Field Programmable Gate Array). The presented converter can operate as a close to ideal voltage or current source, and satisfies the requirements of testing electric motor drive-trains with bidirectional DC–AC converters that are applied in automotive applications. The proposed system was verified by simulation and experiments.
Full article
►▼
Show Figures
Open AccessFeature PaperArticle
In Operando Neutron Radiography Analysis of a High-Temperature Polymer Electrolyte Fuel Cell Based on a Phosphoric Acid-Doped Polybenzimidazole Membrane Using the Hydrogen-Deuterium Contrast Method
by
Yu Lin, Tobias Arlt, Nikolay Kardjilov, Ingo Manke and Werner Lehnert
Cited by 4 | Viewed by 4286
Abstract
In order to characterize high temperature polymer electrolyte fuel cells (HT-PEFCs) in operando, neutron radiography imaging, in combination with the deuterium contrast method, was used to analyze the hydrogen distribution and proton exchange processes in operando. These measurements were then combined with the
[...] Read more.
In order to characterize high temperature polymer electrolyte fuel cells (HT-PEFCs) in operando, neutron radiography imaging, in combination with the deuterium contrast method, was used to analyze the hydrogen distribution and proton exchange processes in operando. These measurements were then combined with the electrochemical impedance spectroscopy measurements. The cell was operated under different current densities and stoichiometries. Neutron images of the active area of the cell were captured in order to study the changeover times when the fuel supply was switched between hydrogen and deuterium, as well as to analyze the cell during steady state conditions. This work demonstrates that the changeover from proton to deuteron (and vice versa) leads to local varying media distributions in the electrolyte, independent of the overall exchange dynamics. A faster proton-to-deuteron exchange was re-discovered when switching the gas supply from H
2 to D
2 than that from D
2 to H
2. Furthermore, the D
2 uptake and discharge were faster at a higher current density. Specifically, the changeover from H to D takes 5–6 min at 200 mA cm
−2, 2–3 min at 400 mA cm
−2 and 1–2 min at 600 mA cm
−2. An effect on the transmittance changes is apparent when the stoichiometry changes.
Full article
►▼
Show Figures
Open AccessArticle
Integrated Sizing and Energy Management for Four-Wheel-Independently-Actuated Electric Vehicles Considering Realistic Constructed Driving Cycles
by
Zhenpo Wang, Changhui Qu, Lei Zhang, Jin Zhang and Wen Yu
Cited by 16 | Viewed by 4213
Abstract
This paper presents an integrated optimization framework of sizing and energy management for four-wheel-independently-actuated electric vehicles. The optimization framework consists of an inner and an outer layer that are responsible for energy management, i.e., torque allocation, and powertrain parameter optimizations. The optimal torque
[...] Read more.
This paper presents an integrated optimization framework of sizing and energy management for four-wheel-independently-actuated electric vehicles. The optimization framework consists of an inner and an outer layer that are responsible for energy management, i.e., torque allocation, and powertrain parameter optimizations. The optimal torque allocation in the inner layer is achieved via the dynamic programming (DP) method while the desirable powertrain parameters in the outer layer are pursued based on the exhaustive method. In order to verify the proposed optimization framework, two driving cycles are constructed to represent the comprehensive and realistic driving conditions. One cycle is built by combining six typical driving cycles, which cover urban, high-way and rural driving styles to enhance representativeness. The other one is synthesized using the Markov chain method based on a vast quantity of real-time operating data of electric vehicles in Beijing. Simulation results demonstrate that the proposed strategy decreases the power consumption by 15.1% and 13.3%, respectively, in the two driving cycles, compared to the non-optimal, even-torque-allocation strategy.
Full article
►▼
Show Figures
Open AccessArticle
Performance Analysis of Permanent Magnet Motors for Electric Vehicles (EV) Traction Considering Driving Cycles
by
Thanh Anh Huynh and Min-Fu Hsieh
Cited by 97 | Viewed by 16414
Abstract
This paper evaluates the electromagnetic and thermal performance of several traction motors for electric vehicles (EVs). Two different driving cycles are employed for the evaluation of the motors, one for urban and the other for highway driving. The electromagnetic performance to be assessed
[...] Read more.
This paper evaluates the electromagnetic and thermal performance of several traction motors for electric vehicles (EVs). Two different driving cycles are employed for the evaluation of the motors, one for urban and the other for highway driving. The electromagnetic performance to be assessed includes maximum motor torque output for vehicle acceleration and the flux weakening capability for wide operating range under current and voltage limits. Thermal analysis is performed to evaluate the health status of the magnets and windings for the prescribed driving cycles. Two types of traction motors are investigated: two interior permanent magnet motors and one permanent magnet-assisted synchronous reluctance motor. The analysis results demonstrate the benefits and disadvantages of these motors for EV traction and provide suggestions for traction motor design. Finally, experiments are conducted to validate the analysis.
Full article
►▼
Show Figures
Open AccessArticle
Gear Ratio Optimization of a Multi-Speed Transmission for Electric Dump Truck Operating on the Structure Route
by
Senqi Tan, Jue Yang, Xinxin Zhao, Tingting Hai and Wenming Zhang
Cited by 31 | Viewed by 8069
Abstract
Research demonstrated that the application of a multi-speed transmission could improve the dynamic and economic performance of electric vehicles. This paper deals with a novel multi-speed transmission for the electric dump truck (EDT) operating on the structure route (SR), which has a definite
[...] Read more.
Research demonstrated that the application of a multi-speed transmission could improve the dynamic and economic performance of electric vehicles. This paper deals with a novel multi-speed transmission for the electric dump truck (EDT) operating on the structure route (SR), which has a definite starting point and end point without complex traffic conditions. To optimize the gear ratio and shift schedule to reduce energy consumption in such conditions, the mathematical model of the transmission and the dynamic model of the EDT are initially required. Following this, the shift schedule is presented according to the motor efficiency map. After that, the gear ratio optimization is carried out by a particle swarm optimization (PSO) algorithm. Moreover, the proposed EDT is compared with an EDT with a single-speed transmission. The simulation results show that the energy consumption is reduced by 6.1%.
Full article
►▼
Show Figures
Open AccessArticle
Experimental Data-Driven Parameter Identification and State of Charge Estimation for a Li-Ion Battery Equivalent Circuit Model
by
Hui Pang and Fengqi Zhang
Cited by 15 | Viewed by 6665
Abstract
It is well known that accurate identification of the key state parameters and State of Charge (SOC) estimation method for a Li-ion battery cell is of great significance for advanced battery management system (BMS) of electric vehicles (EVs), which further facilitates the commercialization
[...] Read more.
It is well known that accurate identification of the key state parameters and State of Charge (SOC) estimation method for a Li-ion battery cell is of great significance for advanced battery management system (BMS) of electric vehicles (EVs), which further facilitates the commercialization of EVs. This study proposed a systematic experimental data-driven parameter identification scheme and an adaptive extended Kalman Filter (AEKF)-based SOC estimation algorithm for a Li-Ion battery equivalent circuit model in EV applications. The key state parameters of Li-ion battery cell were identified based on the second-order resistor capacitor (RC) equivalent circuit model and the experimental battery test data using genetic algorithm (GA). Meanwhile, the proposed parameter identification procedure was validated by carrying out a comparative study of the simulated and experimental output voltage under the same input current profile. Then, SOC estimation was performed based on the AEKF algorithm. Finally, the effectiveness and feasibility of the proposed SOC estimator was verified by loading different operating profiles.
Full article
►▼
Show Figures
Open AccessArticle
An Enhanced Hybrid Switching-Frequency Modulation Strategy for Fuel Cell Vehicle Three-Level DC-DC Converters with Quasi-Z Source
by
Yun Zhang, Jilong Shi, Chuanzhi Fu, Wei Zhang, Ping Wang, Jing Li and Mark Sumner
Cited by 6 | Viewed by 4490
Abstract
For fuel cell vehicles, the fuel cell stack has a soft output characteristic whereby the output voltage drops quickly with the increasing output current. In order to interface the dynamic low voltage of the fuel cell stack with the required constant high voltage
[...] Read more.
For fuel cell vehicles, the fuel cell stack has a soft output characteristic whereby the output voltage drops quickly with the increasing output current. In order to interface the dynamic low voltage of the fuel cell stack with the required constant high voltage (400 V) of the inverter DC link bus for fuel cell vehicles, an enhanced hybrid switching-frequency modulation strategy that can improve the voltage-gain range is proposed in this paper for the boost three-level DC-DC converter with a quasi-Z source (BTL-qZ) employed in fuel-cell vehicles. The proposed modulation strategy retains the same advantages of the original modulation strategy with more suitable duty cycles [1/3, 2/3) which avoids extreme duty cycles. Finally, the experimental results validate the feasibility of the proposed modulation strategy and the correctness of its operating principles. Therefore, the BTL-qZ converter is beneficial to interface the fuel cell stack and the DC bus for fuel cell vehicles by using the proposed modulation strategy.
Full article
►▼
Show Figures
Open AccessArticle
Exploring the Potential of Camber Control to Improve Vehicles’ Energy Efficiency during Cornering
by
Peikun Sun, Annika Stensson Trigell, Lars Drugge, Jenny Jerrelind and Mats Jonasson
Cited by 15 | Viewed by 5421
Abstract
Actively controlling the camber angle to improve energy efficiency has recently gained interest due to the importance of reducing energy consumption and the driveline electrification trend that makes cost-efficient implementation of actuators possible. To analyse how much energy that can be saved with
[...] Read more.
Actively controlling the camber angle to improve energy efficiency has recently gained interest due to the importance of reducing energy consumption and the driveline electrification trend that makes cost-efficient implementation of actuators possible. To analyse how much energy that can be saved with camber control, the effect of changing the camber angles on the forces and moments of the tyre under different driving conditions should be considered. In this paper, Magic Formula tyre models for combined slip and camber are used for simulation of energy analysis. The components of power loss during cornering are formulated and used to explain the influence that camber angles have on the power loss. For the studied driving paths and the assumed driver model, the simulation results show that active camber control can have considerable influence on power loss during cornering. Different combinations of camber angles are simulated, and a camber control algorithm is proposed and verified in simulation. The results show that the camber controller has very promising application prospects for energy-efficient cornering.
Full article
►▼
Show Figures
Open AccessArticle
Thermal Characteristics of an Oscillating Heat Pipe Cooling System for Electric Vehicle Li-Ion Batteries
by
Ri-Guang Chi, Won-Sik Chung and Seok-Ho Rhi
Cited by 50 | Viewed by 9932
Abstract
The heat generation of lithium ion batteries in electric vehicles (EVs) leads to a degradation of energy capacity and lifetime. To solve this problem, a new cooling concept using an oscillating heat pipe (OHP) is proposed. In the present study, an OHP has
[...] Read more.
The heat generation of lithium ion batteries in electric vehicles (EVs) leads to a degradation of energy capacity and lifetime. To solve this problem, a new cooling concept using an oscillating heat pipe (OHP) is proposed. In the present study, an OHP has been adopted for Li-ion battery cooling. Due to the limited space in EVs, the cooling channel is installed on the bottom of the battery module. In the bottom cooling method with an OHP, generated heat can be dissipated easily and conveniently. However, most studies on heat pipes have used bottom heating and top or side cooling methods, so we investigate the various effects of parameters with a top heating/bottom cooling mode with the OHP, i.e., the inclination angle of the system, amount of working fluid charged, the heating amount, and the cold plate temperature with ethanol as a working fluid. The experimental results show that the thermal resistance (0.6 °C/W) and uneven pulsating features influence the heat transfer performance. A heater used as a simulated battery was sustained under 60 °C under 10 W and 14 W heating conditions. This indicates that the proposed cooling system with the bottom cooling is feasible for use as an EV’s battery cooling system.
Full article
►▼
Show Figures
Open AccessFeature PaperReview
Towards Optimal Power Management of Hybrid Electric Vehicles in Real-Time: A Review on Methods, Challenges, and State-Of-The-Art Solutions
by
Ahmed M. Ali and Dirk Söffker
Cited by 110 | Viewed by 11157
Abstract
In light of increasing alerts about limited energy sources and environment degradation, it has become essential to search for alternatives to thermal engine-based vehicles which are a major source of air pollution and fossil fuel depletion. Hybrid electric vehicles (HEVs), encompassing multiple energy
[...] Read more.
In light of increasing alerts about limited energy sources and environment degradation, it has become essential to search for alternatives to thermal engine-based vehicles which are a major source of air pollution and fossil fuel depletion. Hybrid electric vehicles (HEVs), encompassing multiple energy sources, are a short-term solution that meets the performance requirements and contributes to fuel saving and emission reduction aims. Power management methods such as regulating efficient energy flow to the vehicle propulsion, are core technologies of HEVs. Intelligent power management methods, capable of acquiring optimal power handling, accommodating system inaccuracies, and suiting real-time applications can significantly improve the powertrain efficiency at different operating conditions. Rule-based methods are simply structured and easily implementable in real-time; however, a limited optimality in power handling decisions can be achieved. Optimization-based methods are more capable of achieving this optimality at the price of augmented computational load. In the last few years, these optimization-based methods have been under development to suit real-time application using more predictive, recognitive, and artificial intelligence tools. This paper presents a review-based discussion about these new trends in real-time optimal power management methods. More focus is given to the adaptation tools used to boost methods optimality in real-time. The contribution of this work can be identified in two points: First, to provide researchers and scholars with an overview of different power management methods. Second, to point out the state-of-the-art trends in real-time optimal methods and to highlight promising approaches for future development.
Full article
►▼
Show Figures
Open AccessArticle
Continuous Steering Stability Control Based on an Energy-Saving Torque Distribution Algorithm for a Four in-Wheel-Motor Independent-Drive Electric Vehicle
by
Li Zhai, Rufei Hou, Tianmin Sun and Steven Kavuma
Cited by 52 | Viewed by 7026
Abstract
In this paper, a continuous steering stability controller based on an energy-saving torque distribution algorithm is proposed for a four in-wheel-motor independent-drive electric vehicle (4MIDEV) to improve the energy consumption efficiency while maintaining the stability in steering maneuvers. The controller is designed as
[...] Read more.
In this paper, a continuous steering stability controller based on an energy-saving torque distribution algorithm is proposed for a four in-wheel-motor independent-drive electric vehicle (4MIDEV) to improve the energy consumption efficiency while maintaining the stability in steering maneuvers. The controller is designed as a hierarchical structure, including the reference model level, the upper-level controller, and the lower-level controller. The upper-level controller adopts the direct yaw moment control (DYC), which is designed to work continuously during the steering maneuver to better ensure steering stability in extreme situations, rather than working only after the vehicle is judged to be unstable. An adaptive two-hierarchy energy-saving torque distribution algorithm is developed in the lower-level controller with the friction ellipse constraint as a basis for judging whether the algorithm needs to be switched, so as to achieve a more stable and energy-efficient steering operation. The proposed stability controller was validated in a co-simulation of CarSim and Matlab/Simulink. The simulation results under different steering maneuvers indicate that the proposed controller, compared with the conventional servo controller and the ordinary continuous controller, can reduce energy consumption up to 23.68% and improve the vehicle steering stability.
Full article
►▼
Show Figures
Open AccessArticle
Study of the Energy Conversion Process in the Electro-Hydrostatic Drive of a Vehicle
by
Wiesław Grzesikiewicz, Lech Knap, Michał Makowski and Janusz Pokorski
Cited by 3 | Viewed by 4678
Abstract
In the paper, we describe a study of an electro-hydrostatic hybrid drive of a utility van intended for city traffic. In this hybrid drive, the electric drive is periodically accompanied by hydrostatic drive, especially during acceleration and regenerative braking of the vehicle. We
[...] Read more.
In the paper, we describe a study of an electro-hydrostatic hybrid drive of a utility van intended for city traffic. In this hybrid drive, the electric drive is periodically accompanied by hydrostatic drive, especially during acceleration and regenerative braking of the vehicle. We present a mathematical model of the hybrid drive as a set of dynamics and regulation equations of the van traveling at a given speed. On this basis, we construct a computer program which we use to simulate the processes of energy conversion in the electro-hydrostatic drive. The main goal of the numerical simulation is to assess the possibility of reducing energy intensity of the electric drive through such a support of the hydrostatic drive. The obtained results indicate that it is possible to reduce the load on elements of the electric system and, therefore, improve energy conversion.
Full article
►▼
Show Figures
Open AccessArticle
Magnet Shape Optimization of Two-Layer Spoke-Type Axial Flux Interior Permanent Magnet Machines
by
Feng Chai, Yunlong Bi and Yulong Pei
Cited by 3 | Viewed by 6796
Abstract
In this paper, the two-layer spoke-type (TLST) axial flux interior permanent magnet (AFIPM) machine is proposed. Simple flux barriers are added to optimize the air gap flux density, in which way there is no need to change the surface of the rotor. The
[...] Read more.
In this paper, the two-layer spoke-type (TLST) axial flux interior permanent magnet (AFIPM) machine is proposed. Simple flux barriers are added to optimize the air gap flux density, in which way there is no need to change the surface of the rotor. The optimization principle is revealed and the advantages of the TLST AFIPM machine compared with the spoke-type (ST) AFIPM machine are clarified. An optimization design process based on magnetic equivalent circuit combined with idealized and improved air gap flux density waveform is proposed, in which way the calculation time is saved by avoiding an excess of finite element method (FEM) simulations. Finally, 3D FEM simulation is adopted to verify the optimization results.
Full article
►▼
Show Figures
Open AccessArticle
Impact of Different Driving Cycles and Operating Conditions on CO2 Emissions and Energy Management Strategies of a Euro-6 Hybrid Electric Vehicle
by
Claudio Cubito, Federico Millo, Giulio Boccardo, Giuseppe Di Pierro, Biagio Ciuffo, Georgios Fontaras, Simone Serra, Marcos Otura Garcia and Germana Trentadue
Cited by 55 | Viewed by 7980
Abstract
Although Hybrid Electric Vehicles (HEVs) represent one of the key technologies to reduce CO
2 emissions, their effective potential in real world driving conditions strongly depends on the performance of their Energy Management System (EMS) and on its capability to maximize the efficiency
[...] Read more.
Although Hybrid Electric Vehicles (HEVs) represent one of the key technologies to reduce CO
2 emissions, their effective potential in real world driving conditions strongly depends on the performance of their Energy Management System (EMS) and on its capability to maximize the efficiency of the powertrain in real life as well as during Type Approval (TA) tests. Attempting to close the gap between TA and real world CO
2 emissions, the European Commission has decided to introduce from September 2017 the Worldwide Harmonized Light duty Test Procedure (WLTP), replacing the previous procedure based on the New European Driving Cycle (NEDC). The aim of this work is the analysis of the impact of different driving cycles and operating conditions on CO
2 emissions and on energy management strategies of a Euro-6 HEV through the limited number of information available from the chassis dyno tests. The vehicle was tested considering different initial battery State of Charge (SOC), ranging from 40% to 65%, and engine coolant temperatures, from −7 °C to 70 °C. The change of test conditions from NEDC to WLTP was shown to lead to a significant reduction of the electric drive and to about a 30% increase of CO
2 emissions. However, since the specific energy demand of WLTP is about 50% higher than that of NEDC, these results demonstrate that the EMS strategies of the tested vehicle can achieve, in test conditions closer to real life, even higher efficiency levels than those that are currently evaluated on the NEDC, and prove the effectiveness of HEV technology to reduce CO
2 emissions.
Full article
►▼
Show Figures
Open AccessArticle
A High-Frequency Isolation (HFI) Charging DC Port Combining a Front-End Three-Level Converter with a Back-End LLC Resonant Converter
by
Guowei Cai, Duolun Liu, Chuang Liu, Wei Li and Jiajun Sun
Cited by 7 | Viewed by 10025
Abstract
The high-frequency isolation (HFI) charging DC port can serve as the interface between unipolar/bipolar DC buses and electric vehicles (EVs) through the two-power-stage system structure that combines the front-end three-level converter with the back-end logical link control (LLC) resonant converter. The DC output
[...] Read more.
The high-frequency isolation (HFI) charging DC port can serve as the interface between unipolar/bipolar DC buses and electric vehicles (EVs) through the two-power-stage system structure that combines the front-end three-level converter with the back-end logical link control (LLC) resonant converter. The DC output voltage can be maintained within the desired voltage range by the front-end converter. The electrical isolation can be realized by the back-end LLC converter, which has the bus converter function. According to the three-level topology, the low-voltage rating power devices can be adapted for half-voltage stress of the total DC grid, and the PWM phase-shift control can double the equivalent switching frequency to greatly reduce the filter volume. LLC resonant converters have advance characteristics of inverter-side zero-voltage-switching (ZVS) and rectifier-side zero-current switching (ZCS). In particular, it can achieve better performance under quasi-resonant frequency mode. Additionally, the magnetizing current can be modified following different DC output voltages, which have the self-adaptation ZVS condition for decreasing the circulating current. Here, the principles of the proposed topology are analyzed in detail, and the design conditions of the three-level output filter and high-frequency isolation transformer are explored. Finally, a 20 kW prototype with the 760 V input and 200–500 V output are designed and tested. The experimental results are demonstrated to verify the validity and performance of this charging DC port system structure.
Full article
►▼
Show Figures
Open AccessArticle
An Adaptive Square Root Unscented Kalman Filter Approach for State of Charge Estimation of Lithium-Ion Batteries
by
Shulin Liu, Naxin Cui and Chenghui Zhang
Cited by 41 | Viewed by 6324
Abstract
An accurate state of charge (SOC) estimation is of great importance for the battery management systems of electric vehicles. To improve the accuracy and robustness of SOC estimation, lithium-ion battery SOC is estimated using an adaptive square root unscented Kalman filter (ASRUKF) method.
[...] Read more.
An accurate state of charge (SOC) estimation is of great importance for the battery management systems of electric vehicles. To improve the accuracy and robustness of SOC estimation, lithium-ion battery SOC is estimated using an adaptive square root unscented Kalman filter (ASRUKF) method. The square roots of the variance matrices of the SOC and noise can be calculated directly by the ASRUKF algorithm, which ensures the symmetry and nonnegative definiteness of the matrices. The process values and measurement noise covariance can be adaptively adjusted, which greatly improves the accuracy, stability, and self-adaptability of the filter. The effectiveness of the proposed method has been verified through experiments under different operating conditions. The obtained results were compared with those of extended Kalman filter (EKF) and unscented Kalman filter (UKF) , which indicates that the ASRUKF method provides better accuracy, robustness and convergence in the estimation of battery SOC for electric vehicles. The proposed method has a mean SOC estimation error of 0.5% and a maximum SOC estimation error of 0.8%. These errors are lower than those of other methods.
Full article
►▼
Show Figures
Open AccessArticle
Online Lithium-Ion Battery Internal Resistance Measurement Application in State-of-Charge Estimation Using the Extended Kalman Filter
by
Dian Wang, Yun Bao and Jianjun Shi
Cited by 95 | Viewed by 15388
Abstract
The lithium-ion battery is a viable power source for hybrid electric vehicles (HEVs) and, more recently, electric vehicles (EVs). Its performance, especially in terms of state of charge (SOC), plays a significant role in the energy management of these vehicles. The extended Kalman
[...] Read more.
The lithium-ion battery is a viable power source for hybrid electric vehicles (HEVs) and, more recently, electric vehicles (EVs). Its performance, especially in terms of state of charge (SOC), plays a significant role in the energy management of these vehicles. The extended Kalman filter (EKF) is widely used to estimate online SOC as an efficient estimation algorithm. However, conventional EKF algorithms cannot accurately estimate the difference between individual batteries, which should not be ignored. However, the internal resistance of a battery can represent this difference. Therefore, this work proposes using an EKF with internal resistance measurement based on the conventional algorithm. Lithium-ion battery real-time resistances can help the Kalman filter overcome defects from simplistic battery models. In addition, experimental results show that it is useful to introduce online internal resistance to the estimation of SOC.
Full article
►▼
Show Figures
Open AccessArticle
Analysis of Vibrations in Interior Permanent Magnet Synchronous Motors Considering Air-Gap Deformation
by
Yi Li, Feng Chai, Zaixin Song and Zongyang Li
Cited by 27 | Viewed by 6696
Abstract
This paper studies the non-uniform air-gap caused by stator and rotor deformations, together with its effects on the spatial and temporal spectrum of the radial magnetic force density in an interior permanent magnet synchronous motor (IPMSM). According to the mathematical model of the
[...] Read more.
This paper studies the non-uniform air-gap caused by stator and rotor deformations, together with its effects on the spatial and temporal spectrum of the radial magnetic force density in an interior permanent magnet synchronous motor (IPMSM). According to the mathematical model of the deformed air-gap length, the superposition method is adopted to derive the air-gap permeance. Then, the formulas of the magnetic flux field and radial force density of the IPMSM considering air-gap deformation are obtained. Considering the stator oval deformation and the rotor centrifugal distortion in the electromagnetic finite element models (FEMs), the finite element analysis (FEA) and experiments of the investigated IPMSM are carried out to verify the results obtained by the theoretical analysis at different operations. Finally, the mathematical correlation between air-gap deformation and electromagnetic vibration is obtained. The result is helpful in solving problems of mutual influence between electromagnetic and mechanical characteristics during the optimization design of IPMSM.
Full article
►▼
Show Figures
Open AccessArticle
Analysis of Cooling Effectiveness and Temperature Uniformity in a Battery Pack for Cylindrical Batteries
by
Seham Shahid and Martin Agelin-Chaab
Cited by 80 | Viewed by 7829
Abstract
In this paper, techniques to improve cooling and temperature uniformity in a simple battery pack are examined. Four battery pack configurations are developed. In the first configuration, an inlet plenum is added to a simple battery pack. In the second configuration, jet inlets
[...] Read more.
In this paper, techniques to improve cooling and temperature uniformity in a simple battery pack are examined. Four battery pack configurations are developed. In the first configuration, an inlet plenum is added to a simple battery pack. In the second configuration, jet inlets are incorporated along with the inlet plenum, and in the third configuration, multiple vortex generators are added in addition to the inlet plenum. Finally, in the fourth configuration, an inlet plenum, jet inlets, and multiple vortex generators are incorporated into the battery pack. The results conclude that by adding inlet plenum, multiple vortex generators, and jet inlets in the same configuration, significant improvements are observed. The results also show that the maximum temperature of the battery pack is reduced by ~5%, and the temperature difference between the maximum temperature and the minimum temperature exhibited by the battery pack is reduced by 21.5%. Moreover, there is a ~16% improvement in the temperature uniformity of a single cell.
Full article
►▼
Show Figures
Open AccessArticle
Analysis of On-Board Photovoltaics for a Battery Electric Bus and Their Impact on Battery Lifespan
by
Kevin R. Mallon, Francis Assadian and Bo Fu
Cited by 72 | Viewed by 8787
Abstract
Heavy-duty electric powertrains provide a potential solution to the high emissions and low fuel economy of trucks, buses, and other heavy-duty vehicles. However, the cost, weight, and lifespan of electric vehicle batteries limit the implementation of such vehicles. This paper proposes supplementing the
[...] Read more.
Heavy-duty electric powertrains provide a potential solution to the high emissions and low fuel economy of trucks, buses, and other heavy-duty vehicles. However, the cost, weight, and lifespan of electric vehicle batteries limit the implementation of such vehicles. This paper proposes supplementing the battery with on-board photovoltaic modules. In this paper, a bus model is created to analyze the impact of on-board photovoltaics on electric bus range and battery lifespan. Photovoltaic systems that cover the bus roof and bus sides are considered. The bus model is simulated on a suburban bus drive cycle on a bus route in Davis, CA, USA for a representative sample of yearly weather conditions. Roof-mounted panels increased vehicle driving range by 4.7% on average annually, while roof and side modules together increased driving range by 8.9%. However, variations in weather conditions meant that this additional range was not reliably available. For constant vehicle range, rooftop photovoltaic modules extended battery cycle life by up to 10% while modules on both the roof and sides extended battery cycle life by up to 19%. Although side-mounted photovoltaics increased cycle life and range, they were less weight- and cost-effective compared to the roof-mounted panels.
Full article
►▼
Show Figures
Open AccessArticle
Research on the Optimal Charging Strategy for Li-Ion Batteries Based on Multi-Objective Optimization
by
Haitao Min, Weiyi Sun, Xinyong Li, Dongni Guo, Yuanbin Yu, Tao Zhu and Zhongmin Zhao
Cited by 42 | Viewed by 7005
Abstract
Charging performance affects the commercial application of electric vehicles (EVs) significantly. This paper presents an optimal charging strategy for Li-ion batteries based on the voltage-based multistage constant current (VMCC) charging strategy. In order to satisfy the different charging demands of the EV users
[...] Read more.
Charging performance affects the commercial application of electric vehicles (EVs) significantly. This paper presents an optimal charging strategy for Li-ion batteries based on the voltage-based multistage constant current (VMCC) charging strategy. In order to satisfy the different charging demands of the EV users for charging time, charged capacity and energy loss, the multi-objective particle swarm optimization (MOPSO) algorithm is employed and the influences of charging stage number, charging cut-off voltage and weight factors of different charging goals are analyzed. Comparison experiments of the proposed charging strategy and the traditional normal and fast charging strategies are carried out. The experimental results demonstrate that the traditional normal and fast charging strategies can only satisfy a small range of EV users’ charging demand well while the proposed charging strategy can satisfy the whole range of the charging demand well. The relative increase in charging performance of the proposed charging strategy can reach more than 80% when compared to the normal and fast charging dependently.
Full article
►▼
Show Figures
Open AccessArticle
A Fast-Acting Diagnostic Algorithm of Insulated Gate Bipolar Transistor Open Circuit Faults for Power Inverters in Electric Vehicles
by
Lei Yu, Youtong Zhang, Wenqing Huang and Khaled Teffah
Cited by 12 | Viewed by 6787
Abstract
To improve the diagnostic detection speed in electric vehicles, a novel diagnostic algorithm of insulated gate bipolar transistor (IGBT) open circuit faults for power inverters is proposed in this paper. The average of the difference between the actual three-phase current and referential three-phase
[...] Read more.
To improve the diagnostic detection speed in electric vehicles, a novel diagnostic algorithm of insulated gate bipolar transistor (IGBT) open circuit faults for power inverters is proposed in this paper. The average of the difference between the actual three-phase current and referential three-phase current values over one electrical period is used as the diagnostic variable. The normalization method based on the amplitude of the
d-q axis referential current is applied to the diagnostic variables to improve the response speed of diagnosis, and to avoid the noise and the delay caused by signal acquisition. In the parameter discretization process, the variable parameter moving average method (VPMAM) is adopted to solve the variation of the average value over a period with the speed of the motor; hence, the diagnostic reliability of the system is improved. This algorithm is robust, independent of load variations, and has a high resistivity against false alarms. Since only the three-phase current of the motor is utilized for calculations in the time domain, a fast diagnostic detection speed can be achieved, which is significantly essential for real-time control in electric vehicles. The effectiveness of the proposed algorithm is verified by both simulation and experimental results.
Full article
►▼
Show Figures
Open AccessArticle
Analytical Calculation of Magnetic Field Distribution and Stator Iron Losses for Surface-Mounted Permanent Magnet Synchronous Machines
by
Zhen Tian, Chengning Zhang and Shuo Zhang
Cited by 27 | Viewed by 7409
Abstract
Permanent-magnet synchronous machines (PMSMs) are widely used in electric vehicles owing to many advantages, such as high power density, high efficiency, etc. Iron losses can account for a significant component of the total loss in permanent-magnet (PM) machines. Consequently, these losses should be
[...] Read more.
Permanent-magnet synchronous machines (PMSMs) are widely used in electric vehicles owing to many advantages, such as high power density, high efficiency, etc. Iron losses can account for a significant component of the total loss in permanent-magnet (PM) machines. Consequently, these losses should be carefully considered during the PMSM design. In this paper, an analytical calculation method has been proposed to predict the magnetic field distribution and stator iron losses in the surface-mounted permanent magnet (SPM) synchronous machines. The method introduces the notion of complex relative air-gap permeance to take into account the effect of slotting. The imaginary part of the relative air-gap permeance is neglected to simplify the calculation of the magnetic field distribution in the slotted air gap for the surface-mounted permanent-magnet (SPM) machine. Based on the armature reaction magnetic field analysis, the stator iron losses can be estimated by the modified Steinmetz equation. The stator iron losses under load conditions are calculated according to the varying d-q-axis currents of different control methods. In order to verify the analysis method, finite element simulation results are compared with analytical calculations. The comparisons show good performance of the proposed analytical method.
Full article
►▼
Show Figures
Open AccessArticle
Comparison Study of Two Semi-Active Hybrid Energy Storage Systems for Hybrid Electric Vehicle Applications and Their Experimental Validation
by
Haitao Min, Changlu Lai, Yuanbin Yu, Tao Zhu and Cong Zhang
Cited by 28 | Viewed by 8889
Abstract
Both the battery/supercapacitor (SC) and SC/battery are two common semi-active configurations of hybrid energy storage systems (HESSs) in hybrid electric vehicles, which can take advantage of the battery’s and supercapacitor’s respective characteristics, including the energy ability, power ability and the long lifetime. To
[...] Read more.
Both the battery/supercapacitor (SC) and SC/battery are two common semi-active configurations of hybrid energy storage systems (HESSs) in hybrid electric vehicles, which can take advantage of the battery’s and supercapacitor’s respective characteristics, including the energy ability, power ability and the long lifetime. To explore in depth the characteristics and applicability of the two kinds of HESS, an analysis and comparison study is proposed in this paper. Based on the data collected from public transit hybrid electric bus (PTHEB) with battery-only on-board energy storage, the range and distribution probability of electric power/energy demand is comprehensively statistically analyzed with the decomposing and normalizing methods. Accordingly, the performance of each topology under different parameter matching conditions but same mass, volume and cost values with battery-only energy storage, are presented and compared quantitatively. The results show that both HESS configurations can meet the electric power demand of the hybrid electric vehicle (HEV) through reasonable design. In particular, the SC/battery can make better use of the SC features resulting in high efficiency and long life cycles compared with the battery/SC. Equally, it proves that the SC/battery topology is a better choice for the HEV. Finally, an experimental validation of a real HEV is carried out, which indicated that a 7% fuel economy improvement can be achieved by a SC/battery system compared with battery-only topology.
Full article
►▼
Show Figures