World Electric Vehicle Journal

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13 pages, 315 KiB

Open AccessArticle

Cycling Infrastructure for All EPACs Included?

by Nikolaas Van den Steen, Bas de Geus, Jan Cappelle and Lieselot Vanhaverbeke

World Electr. Veh. J. 2022, 13(5), 74; https://doi.org/10.3390/wevj13050074 - 22 Apr 2022

Cited by 3 | Viewed by 2658

Abstract

A modal shift to electric pedal-assisted cycles (EPACs) can help with reaching the transport emission goals of the European Green Deal. With the rising sales of EPACs in Europe, a lack of appropriate (electric) cycling infrastructure remains a major barrier for many potential [...] Read more.

A modal shift to electric pedal-assisted cycles (EPACs) can help with reaching the transport emission goals of the European Green Deal. With the rising sales of EPACs in Europe, a lack of appropriate (electric) cycling infrastructure remains a major barrier for many potential users. This paper discusses the results of a survey about the requirements of (potential) cyclists to design a better cycling infrastructure. The differences in requirements for non-cyclists vs. cyclists and electric cyclists vs. conventional cyclists are discussed using statistical analysis. The key findings are that cyclists and non-cyclists both require wide quality cycling infrastructure with safe crossing points, secure bicycle parking and smart traffic lights. Non-cyclists’ requirements significantly differ from cyclists’ on 12 items, of which rain cover while cycling and parking spots for the car are the most noteworthy. There is (but) one significant difference between the requirements of EPAC users and conventional cyclists: the need for charging points for EPACs along the cycle route. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

11 pages, 3058 KiB

Open AccessArticle

A State-of-Charge Estimation Method Based on Multi-Algorithm Fusion

by Aihua Tang, Peng Gong, Jiajie Li, Kaiqing Zhang, Yapeng Zhou and Zhigang Zhang

World Electr. Veh. J. 2022, 13(4), 70; https://doi.org/10.3390/wevj13040070 - 18 Apr 2022

Cited by 7 | Viewed by 2692

Abstract

Lithium-ion power batteries are widely used in the electric vehicle (EV) industry due to their high working voltage, high energy density, long cycle life, low self-discharge rate, and environmental protection. A multi-algorithm fusion method is proposed in this paper to estimate the battery [...] Read more.

Lithium-ion power batteries are widely used in the electric vehicle (EV) industry due to their high working voltage, high energy density, long cycle life, low self-discharge rate, and environmental protection. A multi-algorithm fusion method is proposed in this paper to estimate the battery state of charge (SOC), establishing the Thevenin model and collecting the terminal voltage residuals when the extended Kalman filter (EKF), adaptive extended Kalman filter (AEKF), and H infinite filter (HIF) estimate the SOC separately. The residuals are fused by Bayesian probability and the weight is obtained, and then the SOC estimated value of the fusion algorithm is obtained from the weight. A comparative analysis of the estimation accuracy of a single algorithm and a fusion algorithm under two different working conditions is made. Experimental results show that the fusion algorithm is more robust in the whole process of SOC estimation, and its estimation accuracy is better than the EKF algorithm. The estimation result for the fusion algorithm under a Dynamic Stress Test (DST) is better than that under a Hybrid Pulse Power Characterization (HPPC) test. With the emergence of cloud batteries, the fusion algorithm is expected to realize real vehicle online application. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 4772 KiB

Open AccessArticle

IPTVisual: Visualisation of the Spatial Energy Flows in Inductive Power Transfer Systems with Arbitrary Winding Shapes

by Cheng Zhang, Xiaoyun Chen, Kunyu Chen and Deyan Lin

World Electr. Veh. J. 2022, 13(4), 63; https://doi.org/10.3390/wevj13040063 - 2 Apr 2022

Cited by 2 | Viewed by 2238

Abstract

Mid-ranged wireless power transfer by induction or inductive power transfer (IPT), including the strong magnetic resonance method, has been widely adopted, in numerous applications where wires are restricted. The energy flow in space, of course, is invisible to engineers. The windings are often [...] Read more.

Mid-ranged wireless power transfer by induction or inductive power transfer (IPT), including the strong magnetic resonance method, has been widely adopted, in numerous applications where wires are restricted. The energy flow in space, of course, is invisible to engineers. The windings are often required to be irregular shapes to accommodate the industrial designs of the products, thus, a visualisation method for energy transfer paths could greatly help the design and optimization of such systems. A time-efficient methodology, including the model, analysis and plot of the three-dimensional energy flow for IPT systems, is proposed in this paper. Algorithms of fast describing arbitrarily shaped windings are proposed and the time complexities are evaluated. A software tool, IPTVisual, is developed. It takes the inputs of key coordinates of the windings, the assignments of voltage and/or current sources, any compensation capacitors and auxiliary circuits, and the required observation points to generate the 3D models of the windings and the Poynting vectors, rendered in web browsers for the most extendable compatibility. Several example scenarios have been tested and the results match with the expected operations. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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17 pages, 2639 KiB

Open AccessArticle

Prediction for the Remaining Useful Life of Lithium–Ion Battery Based on RVM-GM with Dynamic Size of Moving Window

by Jinrui Nan, Bo Deng, Wanke Cao and Zihao Tan

World Electr. Veh. J. 2022, 13(2), 25; https://doi.org/10.3390/wevj13020025 - 19 Jan 2022

Cited by 10 | Viewed by 2431

Abstract

Accurate prediction of the remaining useful life of a lithium–ion battery (LiB) is of paramount importance for ensuring its durable operation. To achieve more accurate prediction with limited data, this paper proposes an RVM-GM algorithm based on dynamic window size. The method combines [...] Read more.

Accurate prediction of the remaining useful life of a lithium–ion battery (LiB) is of paramount importance for ensuring its durable operation. To achieve more accurate prediction with limited data, this paper proposes an RVM-GM algorithm based on dynamic window size. The method combines the advantages of the relevance vector machine (RVM) algorithm and grey predictive model (GM). The RVM is applied to provide the relevance vectors of fitting function and output probability prediction, and the GM is used to obtain the trend prediction with limited data information. The algorithm is further verified by the NASA PCoE lithium–ion battery data repository. The experimental prediction results of different batteries data show that the proposed algorithm has less error while applying a dynamic window size compared with a fixed window size, while it has higher prediction accuracy than particle filter algorithm (PF) and convolutional neural network (CNN), which has verified the effectiveness of the proposed algorithm. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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13 pages, 2287 KiB

Open AccessArticle

Research on Path Planning and Tracking Control of Automatic Parking System

by Bingzhan Zhang, Zhiyuan Li, Yaoyao Ni and Yujie Li

World Electr. Veh. J. 2022, 13(1), 14; https://doi.org/10.3390/wevj13010014 - 1 Jan 2022

Cited by 11 | Viewed by 4063

Abstract

In this paper, we focus on the parking path planning and path tracking control under parallel parking conditions with automatic parking system as the research object. In order to solve the problem of discontinuity of curvature in the path planning of traditional arc-straight [...] Read more.

In this paper, we focus on the parking path planning and path tracking control under parallel parking conditions with automatic parking system as the research object. In order to solve the problem of discontinuity of curvature in the path planning of traditional arc-straight combined curve, a quintic polynomial is used to smooth the path. we design a path tracking controller based on the incremental model predictive control (MPC). The preview control based on pure tracking algorithm is used as the comparison algorithm for path tracking. The feasibility of the controller is verified by building a Simulink/CarSim co-simulation platform. In addition, the practicality of the parking controller is further verified by using the ROS intelligent car in the laboratory environment. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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17 pages, 8387 KiB

Open AccessArticle

Constant-Current and Constant-Voltage Output for Single-Switch WPT System with Composite Shielding Structure

by Quanlei Zhang, Chunfang Wang, Lingyun Yang and Zhihao Guo

World Electr. Veh. J. 2022, 13(1), 13; https://doi.org/10.3390/wevj13010013 - 31 Dec 2021

Cited by 5 | Viewed by 2903

Abstract

With the development of wireless power transfer (WPT), the wireless charging has become a research hotspot. This paper proposes a novel single-switch hybrid compensation topology, which can change the compensation network to realize the constant-current (CC) and constant-voltage (CV) output. The zero voltage [...] Read more.

With the development of wireless power transfer (WPT), the wireless charging has become a research hotspot. This paper proposes a novel single-switch hybrid compensation topology, which can change the compensation network to realize the constant-current (CC) and constant-voltage (CV) output. The zero voltage switching (ZVS) margin can be designed to increase the stability of the system. In addition, the magnetic coupler adopts a composite shielding structure composed of ferrite, nanocrystalline, and aluminium foil. The composite shielding structure has a better shielding effect on magnetic flux leakage, and its weight is lighter. The composite shielding structure is expected to be used in the wireless charging system of electric vehicles (EVs). Finally, an experimental prototype is built to verify the theoretical analysis, and the maximum efficiency can reach 91.4%. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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13 pages, 5333 KiB

Open AccessArticle

Suppression of Cross-Coupling Effect of Hybrid Permanent Magnet Synchronous Motor with Parallel Magnetic Circuit

by Xiao He and Guangqing Bao

World Electr. Veh. J. 2022, 13(1), 11; https://doi.org/10.3390/wevj13010011 - 30 Dec 2021

Cited by 3 | Viewed by 2891

Abstract

Hybrid permanent magnet synchronous motor (HPMSM) has attracted increased attention in recent years due to its adjustable air gap flux. However, as a result of the cross-coupling effect of high- and low-coercive permanent magnets, the precise magnetic adjustment of HPMSM has become increasingly [...] Read more.

Hybrid permanent magnet synchronous motor (HPMSM) has attracted increased attention in recent years due to its adjustable air gap flux. However, as a result of the cross-coupling effect of high- and low-coercive permanent magnets, the precise magnetic adjustment of HPMSM has become increasingly difficult. In order to weaken the cross-coupling effect, two methods of adding magnetic barrier and exciting coil are adopted in this paper. First, the equivalent magnetic circuit model is established, and the theoretical rationality of the weakening method is analyzed. Second, the electromagnetic performance of two weakening methods are analyzed based on the finite element analysis. Finally, the rationality of the theoretical analysis is verified, which provides the structure basis for the precise magnetic adjustment of the hybrid permanent magnet motor. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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11 pages, 4998 KiB

Open AccessArticle

The Integrated Kinetic Energy Recoup Drive (i-KERD): An Optimized Powertrain for EVs, HEVs and FCEVs

by Min Yang, Tao Wang, Chunji Guo, Chris Ellis and Yuefeng Liao

World Electr. Veh. J. 2022, 13(1), 8; https://doi.org/10.3390/wevj13010008 - 28 Dec 2021

Cited by 1 | Viewed by 2484

Abstract

In this paper, a particular form of flywheel hybrid powertrain, namely, the Integrated Kinetic Energy Recoup Drive (i-KERD) is fully explored and its applications for EVs, HEVs and FCEVs in recent years to show the energy-savings and performance enhancement potential of this innovative [...] Read more.

In this paper, a particular form of flywheel hybrid powertrain, namely, the Integrated Kinetic Energy Recoup Drive (i-KERD) is fully explored and its applications for EVs, HEVs and FCEVs in recent years to show the energy-savings and performance enhancement potential of this innovative powertrain technology. It is shown that the i-KERD is a small highspeed flywheel integrated into an e-CVT, or power-split hybrid drive. Under NEDC or WLTC, typically it can achieve some 40% energy savings and >50% gain in 0–100 kph acceleration due to effective regenerative braking mechanism of the integrated flywheel power system. In addition to its “peak-shaving” capability, the highly-efficient, long-life flywheel power on-board, is able to keep the kinetic energy of the vehicle fully recycled, rather than dissipated during braking. The i-KERD technology has also been applied to urban railway transportation (i.e., underground railway) and off-road heavy construction equipment, where regenerative braking plays a great role on energy efficiency. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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10 pages, 3601 KiB

Open AccessArticle

Dual-Side Phase-Shift Control for Strongly Coupled Series–Series Compensated Electric Vehicle Wireless Charging Systems

by Yiming Zhang, Zhiwei Shen, Yuanchao Wu, Hui Wang and Wenbin Pan

World Electr. Veh. J. 2022, 13(1), 6; https://doi.org/10.3390/wevj13010006 - 26 Dec 2021

Cited by 3 | Viewed by 2359

Abstract

Wireless power transfer (WPT) for electric vehicles is an emerging technology and a future trend. To increase power density, the coupling coefficient of coils can be designed to be large, forming a strongly coupled WPT system, different from the conventional loosely coupled WPT [...] Read more.

Wireless power transfer (WPT) for electric vehicles is an emerging technology and a future trend. To increase power density, the coupling coefficient of coils can be designed to be large, forming a strongly coupled WPT system, different from the conventional loosely coupled WPT system. In this way, the power density and efficiency of the WPT system can be improved. This paper investigates the dual-side phase-shift control of the strongly coupled series–series compensated WPT systems. The mathematical models based on the conventional first harmonic approximation and differential equations for the dual-side phase-shift control are built and compared. The dual-side phase-shift angle and its impact on the power transfer direction and soft switching are investigated. It is found that synchronous rectification at strong couplings can lead to hard switching because the dual-side phase shift in this case is over 90°. In comparison, a relatively high efficiency and soft switching can be realized when the dual-side phase shift is below 90°. The experimental results have validated the analysis. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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10 pages, 5392 KiB

Open AccessArticle

Optimization of TSPWM for Common-Mode Voltage Reduction in Vehicular Electric Drive System

by Shang Jiang and Yuan Wang

World Electr. Veh. J. 2022, 13(1), 5; https://doi.org/10.3390/wevj13010005 - 24 Dec 2021

Cited by 1 | Viewed by 2387

Abstract

Common-mode voltage can be reduced effectively by optimized modulation methods without increasing additional costs. However, the existing methods cannot satisfy the requirements of the vehicular electric-drive application. This paper optimizes the tri-state voltage modulation method to reduce the common-mode voltage for vehicular electric [...] Read more.

Common-mode voltage can be reduced effectively by optimized modulation methods without increasing additional costs. However, the existing methods cannot satisfy the requirements of the vehicular electric-drive application. This paper optimizes the tri-state voltage modulation method to reduce the common-mode voltage for vehicular electric drive system applications. Firstly, the discontinuous switching issue during sector transition is analyzed. Under the limit of two switching times in one period, multiple alignments combination is proposed to address that issue. Secondly, the zero-voltage time intervals in different modulation ranges are explored. This paper proposes an unsymmetric translation method to reconstruct the voltage vector, and then the minimum zero-voltage time interval is controlled to enough value for safe switching. Finally, the proposed methods have been validated through experiments on a vehicular electric drive system. The results show that the common-mode voltage can be reduced effectively in the whole range with the optimized tri-state voltage modulation method. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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15 pages, 8416 KiB

Open AccessArticle

A Design Technique of Traction Motor for Efficiency Improvement Based on Multiobjective Optimization

by Shoulun Guo, Huichao Zhao, Yu Wang, Xiangrui Yin, Hongyang Qi, Pei Li and Zhanxi Lin

World Electr. Veh. J. 2021, 12(4), 260; https://doi.org/10.3390/wevj12040260 - 11 Dec 2021

Cited by 9 | Viewed by 3108

Abstract

With the increasing demand of driving range of new energy vehicle (NEV), design optimization for energy efficiency of traction motors became more important. However, traction motor design is complex since multiple objectives should be satisfied, such as the required torque-speed operating range and [...] Read more.

With the increasing demand of driving range of new energy vehicle (NEV), design optimization for energy efficiency of traction motors became more important. However, traction motor design is complex since multiple objectives should be satisfied, such as the required torque-speed operating range and package and thermal constraints. This dramatically increases the computation time of the design optimization process, while the additional energy efficiency objective of the whole driving cycle. This paper proposes an equivalent driving cycle points extraction method, based on energy consumption equivalence to facilitate the design optimization of traction motors. This paper presents necessary rules of multiobjective optimization methods, and then gives an optimization process and proves the effectiveness. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 27974 KiB

Open AccessArticle

A Numerical Simulation on the Leakage Event of a High-Pressure Hydrogen Dispenser

by Benjin Wang, Yahao Shen, Hong Lv and Pengfei He

World Electr. Veh. J. 2021, 12(4), 259; https://doi.org/10.3390/wevj12040259 - 10 Dec 2021

Cited by 6 | Viewed by 2915

Abstract

For the sake of the increasing demand of hydrogen fuel cell vehicles, there are more concerns on the safety of hydrogen refueling stations. As one of the key pieces of equipment, the hydrogen dispenser has drawn attention on this aspect since it involves [...] Read more.

For the sake of the increasing demand of hydrogen fuel cell vehicles, there are more concerns on the safety of hydrogen refueling stations. As one of the key pieces of equipment, the hydrogen dispenser has drawn attention on this aspect since it involves massive manual operations and may be bothered by a high probability of failure. In this paper, a numerical study is conducted to simulate the possible leakage events of the hydrogen dispenser based on a prototype in China whose working pressure is 70 MPa. The leakage accident is analyzed with respect to leakage sizes, leak directions, and the time to stop the leakage. It is found that, due to the large mass flow rate under such high pressure, the leak direction and the layout of the components inside the dispenser become insignificant, and the ignitable clouds will form inside the dispenser in less than 1 s if there is a leakage of 1% size of the main tube. The ignitable clouds will form near the vent holes outside the dispenser, which may dissipate quickly if the leakage is stopped. On the other hand, the gas inside the dispenser will remain ignitable for a long time, which asks for a design with no possible ignition source inside. The results can be useful in optimizing the design of the dispenser, regarding the reaction time and sensitivity requirements of the leakage detector, the size and amount of vent holes, etc. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 4193 KiB

Open AccessArticle

Online Capacity Estimation for Lithium-Ion Batteries Based on Semi-Supervised Convolutional Neural Network

by Yi Wu and Wei Li

World Electr. Veh. J. 2021, 12(4), 256; https://doi.org/10.3390/wevj12040256 - 6 Dec 2021

Cited by 3 | Viewed by 2506

Abstract

Accurate capacity estimation can ensure the safe and reliable operation of lithium-ion batteries in practical applications. Recently, deep learning-based capacity estimation methods have demonstrated impressive advances. However, such methods suffer from limited labeled data for training, i.e., the capacity ground-truth of lithium-ion batteries. [...] Read more.

Accurate capacity estimation can ensure the safe and reliable operation of lithium-ion batteries in practical applications. Recently, deep learning-based capacity estimation methods have demonstrated impressive advances. However, such methods suffer from limited labeled data for training, i.e., the capacity ground-truth of lithium-ion batteries. A capacity estimation method is proposed based on a semi-supervised convolutional neural network (SS-CNN). This method can automatically extract features from battery partial-charge information for capacity estimation. Furthermore, a semi-supervised training strategy is developed to take advantage of the extra unlabeled sample, which can improve the generalization of the model and the accuracy of capacity estimation even in the presence of limited labeled data. Compared with artificial neural networks and convolutional neural networks, the proposed method is demonstrated to improve capacity estimation accuracy. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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14 pages, 4700 KiB

Open AccessArticle

Fault Diagnosis for PEMFC Water Management Subsystem Based on Learning Vector Quantization Neural Network and Kernel Principal Component Analysis

by Shuna Jiang, Qi Li, Rui Gan and Weirong Chen

World Electr. Veh. J. 2021, 12(4), 255; https://doi.org/10.3390/wevj12040255 - 4 Dec 2021

Cited by 6 | Viewed by 2595

Abstract

To solve the problem of water management subsystem fault diagnosis in a proton exchange membrane fuel cell (PEMFC) system, a novel approach based on learning vector quantization neural network (LVQNN) and kernel principal component analysis (KPCA) is proposed. In the proposed approach, the [...] Read more.

To solve the problem of water management subsystem fault diagnosis in a proton exchange membrane fuel cell (PEMFC) system, a novel approach based on learning vector quantization neural network (LVQNN) and kernel principal component analysis (KPCA) is proposed. In the proposed approach, the KPCA method is used for processing strongly coupled fault data with a high dimension to reduce the data dimension and to extract new low-dimensional fault feature data. The LVQNN method is used to carry out fault recognition using the fault feature data. The effectiveness of the proposed fault detection method is validated using the experimental data of the PEMFC power system. Results show that the proposed method can quickly and accurately diagnose the three health states: normal state, water flooding failure and membrane dry failure, and the recognition accuracy can reach 96.93%. Therefore, the method proposed in this paper is suitable for processing the fault data with a high dimension and abundant quantities, and provides a reference for the application of water management subsystem fault diagnosis of PEMFC. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 5118 KiB

Open AccessArticle

Nonlinear Varying-Network Magnetic Circuit Analysis of Consequent-Pole Permanent-Magnet Motor for Electric Vehicles

by Hui Wang, Kwok Tong Chau, Christopher H. T. Lee, C. C. Chan and Tengbo Yang

World Electr. Veh. J. 2021, 12(4), 254; https://doi.org/10.3390/wevj12040254 - 1 Dec 2021

Cited by 3 | Viewed by 2571

Abstract

To conserve rare earth resources, consequent-pole permanent-magnet (CPPM) machine has been studied, which employs iron-pole to replace half PM poles. Meanwhile, to increase flux-weakening ability, hybrid excitation CPPM machine with three-dimensional (3-D) flux flow has been proposed. Considering finite element method (FEM) is [...] Read more.

To conserve rare earth resources, consequent-pole permanent-magnet (CPPM) machine has been studied, which employs iron-pole to replace half PM poles. Meanwhile, to increase flux-weakening ability, hybrid excitation CPPM machine with three-dimensional (3-D) flux flow has been proposed. Considering finite element method (FEM) is time-consuming, for the analysis of the CPPM machine, this paper presents a nonlinear varying-network magnetic circuit (NVNMC), which can analytically calculate the corresponding electromagnetic performances. The key is to separate the model of CPPM machine into different elements reasonably; thus, the reluctances and magnetomotive force (MMF) sources in each element can be deduced. While taking into account magnetic saturation in the iron region, the proposed NVNMC method can accurately predict the 3-D magnetic field distribution, hence determining the corresponding back-electromotive force and electromagnetic power. Apart from providing fast calculation, this analytical method can provide physical insight on how to optimize the design parameters of this CPPM machine. Finally, the accuracy of the proposed model is verified by comparing the analytical results with the results obtained by using FEM. As a result, with so many desired attributes, this method can be employed for machine initial optimization to achieve higher power density. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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11 pages, 1210 KiB

Open AccessArticle

Parameter Matching Method of a Battery-Supercapacitor Hybrid Energy Storage System for Electric Vehicles

by Fengchen Liu, Chun Wang and Yunrong Luo

World Electr. Veh. J. 2021, 12(4), 253; https://doi.org/10.3390/wevj12040253 - 1 Dec 2021

Cited by 19 | Viewed by 3499

Abstract

To satisfy the high-rate power demand fluctuations in the complicated driving cycle, electric vehicle (EV) energy storage systems should have both high power density and high energy density. In order to obtain better energy and power performances, a combination of battery and supercapacitor [...] Read more.

To satisfy the high-rate power demand fluctuations in the complicated driving cycle, electric vehicle (EV) energy storage systems should have both high power density and high energy density. In order to obtain better energy and power performances, a combination of battery and supercapacitor are utilized in this work to form a semi-active hybrid energy storage system (HESS). A parameter matching method of battery-supercapacitor HESS for electric vehicles (EVs) is proposed. This method can meet the performance indicators of EVs in terms of power and energy for parameter matching. The result shows that optimized parameter matching is obtained by reducing the weight and cost. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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13 pages, 2759 KiB

Open AccessArticle

Research on New Energy Vehicle Market Penetration Rate Based on Nested Multinominal Logit Model

by Kexin Liu, Hong Shi, Bin Liu and Xiaorong Jian

World Electr. Veh. J. 2021, 12(4), 249; https://doi.org/10.3390/wevj12040249 - 21 Nov 2021

Cited by 1 | Viewed by 3545

Abstract

This article uses the NMNL (nested multinominal logit) model to analyze the impact of different policies on the cost of owning a vehicle by a consumer and discusses the changes in the share of various fuel-driven types of passenger vehicles that may be [...] Read more.

This article uses the NMNL (nested multinominal logit) model to analyze the impact of different policies on the cost of owning a vehicle by a consumer and discusses the changes in the share of various fuel-driven types of passenger vehicles that may be brought by different policy portfolios. This article also considers the differences in the development of various technical routes, conducts the nested classification calculation of different models, divides the differences in product preferences and obtains the market share results that are more in line with the market development status, providing a basis for the formulation of policies related to new energy vehicles. The study found that the popularization of NEVs requires more cost-reducing measures. As policies that consumers can perceive, consumers are more sensitive to fiscal and taxation policies than other types of policies. Based on the calculation of policy effects, this article recommends a policy plan to gradually impose vehicle purchase tax on NEVs after 2024, increase the fuel tax rate in stages after 2025, and impose an excise tax on BEVs and FCEVs after 2030. The plan can guarantee the stability of support for NEVs and the gradual reduction of financial investment. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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11 pages, 3037 KiB

Open AccessArticle

A Stator Fault Diagnosis Method Based on the Offline Motor Parameter Measurement for PMSM

by Jing Tang, Chao Liang, Yuanhang Wang, Shuhan Lu and Jian Zhou

World Electr. Veh. J. 2021, 12(4), 248; https://doi.org/10.3390/wevj12040248 - 20 Nov 2021

Cited by 8 | Viewed by 2374

Abstract

The permanent magnet synchronous motor (PMSM) is used widely in electric vehicle application due to its high-power density and efficiency. Stator fault is a frequently fault in the motor as it usually works in a harsh environment. Therefore, a stator fault diagnosis method [...] Read more.

The permanent magnet synchronous motor (PMSM) is used widely in electric vehicle application due to its high-power density and efficiency. Stator fault is a frequently fault in the motor as it usually works in a harsh environment. Therefore, a stator fault diagnosis method based on the offline motor parameter measurement is proposed to detect and evaluate the stator fault in this paper. Firstly, the line-to-line resistance and inductance of a healthy motor are analyzed when a DC voltage and a high-frequency voltage are excited to the motor respectively, where the DC and AC equivalent circuits at a standstill are introduced. Then, to analyze the resistance and inductance of the stator fault, an extra branch is added to the fault part to obtain the fault equivalent circuits. Accordingly, the stator fault resistance and inductance are derived, and then the resistance and inductance differences between healthy and fault motors are analyzed to provide the basis for the stator fault detection. Furthermore, the fault indicators are defined based on the resistance and inductance differences when a motor has a stator fault. Hence the stator fault severity and location can be evaluated by using these fault indicators. Finally, the experimental results from a 400 W permanent magnet synchronous motor are demonstrated to validate the proposed method. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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14 pages, 6683 KiB

Open AccessArticle

Electrical Interoperability Evaluating of Wireless Electric Vehicle Charging Systems Based on Impedance Space

by Bingkun Shi, Fuyuan Yang, Bin Wei and Minggao Ouyang

World Electr. Veh. J. 2021, 12(4), 245; https://doi.org/10.3390/wevj12040245 - 16 Nov 2021

Cited by 4 | Viewed by 2532

Abstract

In the commercialization process of wireless electric vehicle charging (WEVC), it is essential to ensure the interoperability between diverse WEVC systems due to the wide application of various coil configurations and compensation topologies. This paper proposes a novel electrical interoperability evaluation method based [...] Read more.

In the commercialization process of wireless electric vehicle charging (WEVC), it is essential to ensure the interoperability between diverse WEVC systems due to the wide application of various coil configurations and compensation topologies. This paper proposes a novel electrical interoperability evaluation method based on impedance indices and corresponding feasible space in the complex plane. Firstly, the electromagnetic description of the coil system is introduced to reveal the energy flow process of WEVC system. Further, two key impedance indices and their feasible space are derived and verified. Interoperability evaluation results show that the reference devices in Chinese WEVC standard GB/T 38775.6 and GB/T 38775.7 are able to achieve the requirements of power capability. Moreover, it is necessary to reduce the duty cycle of rectifier when the battery voltage rises so as to narrow down the variation of load resistance and avoid dangerous working conditions. The proposed method can effectively evaluate the electrical interoperability of WEVC systems from different manufacturers under different power or distance levels before conducting experiments. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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10 pages, 2282 KiB

Open AccessArticle

Optimal Planning of Electric Vehicle Charging Station Considering Mutual Benefit of Users and Power Grid

by Hui Hou, Junyi Tang, Bo Zhao, Leiqi Zhang, Yifan Wang and Changjun Xie

World Electr. Veh. J. 2021, 12(4), 244; https://doi.org/10.3390/wevj12040244 - 15 Nov 2021

Cited by 16 | Viewed by 4637

Abstract

A reasonable plan for charging stations is critical to the widespread use of electric vehicles. In this paper, we propose an optimal planning method for electric vehicle charging stations. First of all, we put forward a forecasting method for the distribution of electric [...] Read more.

A reasonable plan for charging stations is critical to the widespread use of electric vehicles. In this paper, we propose an optimal planning method for electric vehicle charging stations. First of all, we put forward a forecasting method for the distribution of electric vehicle fast charging demand in urban areas. Next, a new mathematical model that considers the mutual benefit of electric vehicle users and the power grid is set up, aiming to minimize the social cost of charging stations. Then, the model is solved by the Voronoi diagram combined with improved particle swarm optimization. In the end, the proposed method is applied to an urban area, simulation results demonstrate that the proposed method can yield optimal location and capacity of each charging station. A contrasting case is carried out to verify that improved particle swarm optimization is more effective in finding the global optimal solution than particle swarm optimization. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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18 pages, 4157 KiB

Open AccessArticle

Multistage and Dynamic Layout Optimization for Electric Vehicle Charging Stations Based on the Behavior Analysis of Travelers

by Feng Chen, Minling Feng, Bing Han and Shaofeng Lu

World Electr. Veh. J. 2021, 12(4), 243; https://doi.org/10.3390/wevj12040243 - 15 Nov 2021

Cited by 5 | Viewed by 3327

Abstract

Electric vehicles (EV) are growing fast in recent years with the widespread concern about carbon neutrality. The development of charging infrastructures needs to be in phase with EV both in terms of quantity and charging time to decrease the range anxiety of EV [...] Read more.

Electric vehicles (EV) are growing fast in recent years with the widespread concern about carbon neutrality. The development of charging infrastructures needs to be in phase with EV both in terms of quantity and charging time to decrease the range anxiety of EV users and resource waste. This paper proposed a multistage and dynamic layout optimization model based on mixed integer linear programming (MILP) for EV charging stations (CSs) to minimize the total social costs (TSC) consisting of the detour cost of EV users and the construction, relocation, and operating cost of CSs. The charging satisfaction coefficient and M/M/S/K model of queuing theory has been introduced to determine the desirable charging supply. The spatial-temporal distribution of charging demand was modeled based on the behavior analysis of travelers and over the discrete-time intervals for a day. Comparison studies based on the Sioux Falls network reveal that TSC with a multistage optimization strategy will drop 8.79% from that with a one-time optimization strategy. Charging service quality, relocation cost, and road network scales have a significant impact on the optimization results according to the sensitivity analysis. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 1365 KiB

Open AccessArticle

Aggregate Electric Vehicles in Demand Side for Ancillary Service

by Xianglu Liu, Xianglong Li, Haiyang Chen, Wenbin Zhou, Zhou Sun and Hao Xu

World Electr. Veh. J. 2021, 12(4), 242; https://doi.org/10.3390/wevj12040242 - 15 Nov 2021

Viewed by 2467

Abstract

This paper investigates the win-win commercialization mode of aggregating electric vehicles (EVs) in demand side for ancillary service. We have conducted a half-year-long incentive verification experiment covering 10,066 electric vehicle owners in Beijing. Based on the experimental results, we develop an incentive-based mechanism [...] Read more.

This paper investigates the win-win commercialization mode of aggregating electric vehicles (EVs) in demand side for ancillary service. We have conducted a half-year-long incentive verification experiment covering 10,066 electric vehicle owners in Beijing. Based on the experimental results, we develop an incentive-based mechanism that enables electric vehicles to participate the wholesale capacity market through an aggregator. The aggregator, which is held by charging service operators can make a profit by designing a smart pricing policy. In this process, not only the electric vehicle owners but also the utility can gain benefits. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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15 pages, 6166 KiB

Open AccessArticle

Analysis and Improvement Measures of Driving Range Attenuation of Electric Vehicles in Winter

by Shuoyuan Mao, Meilin Han, Xuebing Han, Jie Shao, Yong Lu, Languang Lu and Minggao Ouyang

World Electr. Veh. J. 2021, 12(4), 239; https://doi.org/10.3390/wevj12040239 - 12 Nov 2021

Cited by 12 | Viewed by 3481

Abstract

A great many EVs in cold areas suffer from range attenuation in winter, which causes driver anxiety concerning the driving range, representing a hot topic. Many researchers have analyzed the reasons for range attenuation but the coupling mechanism of the battery as well [...] Read more.

A great many EVs in cold areas suffer from range attenuation in winter, which causes driver anxiety concerning the driving range, representing a hot topic. Many researchers have analyzed the reasons for range attenuation but the coupling mechanism of the battery as well as the vehicle and driving conditions have not been clearly estimated. To quantitatively investigate the driving range attenuation of electric vehicles (EVs) during winter, an EV model mainly integrated with a passenger-cabin thermal model, battery model, and vehicle dynamic model was constructed and simulated based on the mass-produced Wuling HongGuang Mini EV. Real vehicle dynamic driving data was used to validate the model. Based on NEDC driving conditions, the driving range calculation formula and energy flow diagram analysis method were used. The reason for attenuation was evaluated quantitatively. Results show that battery energy loss and breaking recovery energy loss contribute nearly half of the range attenuation, which may be alleviated by battery preheating. Suggestions for extending driving range are proposed based on the research. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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7 pages, 21697 KiB

Open AccessArticle

Intelligent Power Unit Parameters Design and the Influence Analyses

by Zhanshan Zhu, Huichao Zhao, Xiaolu Liu, Hongbao Wang and Zhiqiang Liu

World Electr. Veh. J. 2021, 12(4), 238; https://doi.org/10.3390/wevj12040238 - 11 Nov 2021

Viewed by 2081

Abstract

The power unit is mainly responsible for the power converter’s function of the electric vehicle, which converts the DC power from the battery to the AC power to drive the motor. Therefore, the parasitic parameters of the power unit will directly affect the [...] Read more.

The power unit is mainly responsible for the power converter’s function of the electric vehicle, which converts the DC power from the battery to the AC power to drive the motor. Therefore, the parasitic parameters of the power unit will directly affect the output performance of the vehicle. In this paper, the parasitic parameters of the power unit are analyzed. By using an asymmetric design, the capacitor cost and performance are balanced. Moreover, the structure of the busbar is optimized according to the reasonable theoretical analysis. The simulation comparison before and after the optimization, and the comparison results of the measurement results by the double pulse test, are given to verify the optimization. Additionally, the ESL of the busbar is reduced by 10 nH. The results will offer some references to the power unit design. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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20 pages, 3156 KiB

Open AccessArticle

Study on a New Static Sealing Method and Sealing Performance Evaluation Model for PEMFC

by Xiaoyu Huang, Jinghui Zhao, Yichun Wang, Yuchao Ke and Zixi Wang

World Electr. Veh. J. 2021, 12(4), 237; https://doi.org/10.3390/wevj12040237 - 11 Nov 2021

Cited by 1 | Viewed by 2788

Abstract

The long-term stability and durability of seals are critical for various instruments and types of equipment. For static sealing, an important sealing state, there are currently two representative sealing methods, namely, pre-compressing static sealing and adhesive static sealing. In this paper, the characteristics [...] Read more.

The long-term stability and durability of seals are critical for various instruments and types of equipment. For static sealing, an important sealing state, there are currently two representative sealing methods, namely, pre-compressing static sealing and adhesive static sealing. In this paper, the characteristics and shortcomings of these sealing methods are summarized. At present, some static sealing requirements are urgent and difficult. For example, the deterioration of the sealing performance is an important factor which limits the service life of proton exchange membrane fuel cells and redox flow batteries. Therefore, a new method of static sealing whose sealing materials are rubber elastomers is proposed, named alterable static sealing. Then, its sealing processes are proposed. Furthermore, the actual contact area ratio r is used as the standard for sealability. Based on the mathematical model of pre-compressing static sealing, the influence of interface bonding was considered, and the mathematical model of alterable static sealing was established. Moreover, the compensatory effect of alterable static sealing on the static sealing capacity of rubber elastomers was proved. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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39 pages, 2037 KiB

Open AccessArticle

Vehicle to Grid Impacts on the Total Cost of Ownership for Electric Vehicle Drivers

by Dominik Huber, Quentin De Clerck, Cedric De Cauwer, Nikolaos Sapountzoglou, Thierry Coosemans and Maarten Messagie

World Electr. Veh. J. 2021, 12(4), 236; https://doi.org/10.3390/wevj12040236 - 11 Nov 2021

Cited by 13 | Viewed by 5071

Abstract

Electric vehicles (EV) are foreseen as one major technology toward decarbonizing the mobility sector. At the same time, Vehicle to Grid (V2G) technology opens a new market for EV owners. This article identifies the impacts of providing V2G services on the Total Cost [...] Read more.

Electric vehicles (EV) are foreseen as one major technology toward decarbonizing the mobility sector. At the same time, Vehicle to Grid (V2G) technology opens a new market for EV owners. This article identifies the impacts of providing V2G services on the Total Cost of Ownership (TCO) of EVs. Thus, we studied EVs in private, semi-public and public charging cases, considering two different V2G revenue streams. The included V2G services were: (i) local load balancing to balance the peaks and valleys of the electricity demands of buildings and (ii) an imbalance service to enhance grid stability. In this paper, the impact of these two V2G services is quantified and considered in the TCO calculations. To the authors’ knowledge, no comparable study incorporating the same V2G services exists in the literature. The TCO is calculated with real-life data for four different EVs currently available in the market. As a result, the V2G TCO ranges from €33.167 to €61.436 over an average of nine years for the Flanders region (Belgium). Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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18 pages, 4652 KiB

Open AccessArticle

Energy Management Method for Fast-Charging Stations with the Energy Storage System to Alleviate the Voltage Problem of the Observation Node

by Rui Ye, Xueliang Huang and Zexin Yang

World Electr. Veh. J. 2021, 12(4), 234; https://doi.org/10.3390/wevj12040234 - 11 Nov 2021

Viewed by 1498

Abstract

Large-scale fast charging of electric vehicles (EVs) probably causes voltage deviation problems in the distribution network. Installing energy storage systems (ESSs) in the fast-charging stations (FCSs) and formulating appropriate active power plans for ESSs is an effective way to reduce the local voltage [...] Read more.

Large-scale fast charging of electric vehicles (EVs) probably causes voltage deviation problems in the distribution network. Installing energy storage systems (ESSs) in the fast-charging stations (FCSs) and formulating appropriate active power plans for ESSs is an effective way to reduce the local voltage deviation problem. Some deterministic centralized strategies used for ESSs at FCSs are proposed to solve the voltage deviation problem mentioned above. However, the randomness of the EV load is very large, which can probably reduce the effects of deterministic centralized strategies. A fast and reliable centralized strategy considering the randomness of the EV load for ESSs is a key requirement. Therefore, we propose in this paper a day-ahead scheduling strategy with the aim of maximizing the probability of the nodal voltage change being smaller than a preset limit at the observation node. In the proposed strategy, the uncertainty of EV load is taken into account and the probability of the voltage change of an observation node is quantified by a proposed analytic assessment model (AMM). Furthermore, a voltage change optimization model (VCOM) based on a novel control parameter β is proposed, where β can be used as a constraint to suppress the nodal voltage change at the observation node. Finally, the IEEE 33-bus test system is used to verify the effectiveness of the proposed day-ahead ESS strategy. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 2253 KiB

Open AccessArticle

A New On-board Charging-Driving Integrated Topology for V2G Technology

by Fangxu Zhang, Daohan Wang, Chen Peng, Zhenkang Feng, Junchen Li, Wentao Feng, Yang Li and Xiuhe Wang

World Electr. Veh. J. 2021, 12(4), 231; https://doi.org/10.3390/wevj12040231 - 10 Nov 2021

Cited by 1 | Viewed by 1948

Abstract

The performance of batteries and on-board chargers (such as the volume in the car, energy storage capacity and charging speed) needs to be improved, which has become one of the main factors restricting the development of electric vehicles. The development of Vehicles to [...] Read more.

The performance of batteries and on-board chargers (such as the volume in the car, energy storage capacity and charging speed) needs to be improved, which has become one of the main factors restricting the development of electric vehicles. The development of Vehicles to Grid technology puts forward higher requirements for chargers. With the development of Vehicles to Grid (V2G) technology, more realizable functions put forward higher requirements for chargers. To solve the problem of charging system in electric vehicle, a charging-driving integrated topology was designed, which makes full use of two-stator motor and inverters to be transformed to a charging system. The supercapacitor and the battery are used to form the hybrid power system. In the driving mode, the startup and acceleration performance of the vehicle are improved. In the charging mode, the various functions of Vehicles to Grid technology can be satisfied, and the electrical isolation is realized. This topology not only improves the power, but also greatly reduces the charging/discharging times of the battery, and improves the overall performance of the system. The feasibility is verified by simulation. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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10 pages, 5861 KiB

Open AccessArticle

Research on Multiphysics Coupling Relationship for the IPT System in Seawater Environment

by Kehan Zhang and Yue An

World Electr. Veh. J. 2021, 12(4), 230; https://doi.org/10.3390/wevj12040230 - 10 Nov 2021

Viewed by 1319

Abstract

Wireless charging in the marine environment has problems such as high loss and low efficiency. In order to solve these problems, based on the wireless power transmission technology in the seawater environment, this paper studies the multi-physical field coupling relationship of the underwater [...] Read more.

Wireless charging in the marine environment has problems such as high loss and low efficiency. In order to solve these problems, based on the wireless power transmission technology in the seawater environment, this paper studies the multi-physical field coupling relationship of the underwater IPT system. Through researching on the law of mutual influence and interaction between the fields, the relationship between the physical fields is established. The software is used to establish a system simulation model, the dataset is solved and analyzed to get the distribution of electric field, magnetic field, thermal field, and flow field, which provides a theoretical basis for the model and optimization of the IPT system in the seawater. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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18 pages, 1106 KiB

Open AccessArticle

Business Model Quantification Framework for the Core Participants of the EV Charging Market

by Andrei Goncearuc, Nikolaos Sapountzoglou, Cedric De Cauwer, Thierry Coosemans, Maarten Messagie and Thomas Crispeels

World Electr. Veh. J. 2021, 12(4), 229; https://doi.org/10.3390/wevj12040229 - 10 Nov 2021

Cited by 5 | Viewed by 3071

Abstract

The rapid growth of the electrical vehicle (EV) market over the last decade has rendered the existence and accuracy of the business models of the EV charging market a critical factor for a company’s success. To address this issue, this paper presents a [...] Read more.

The rapid growth of the electrical vehicle (EV) market over the last decade has rendered the existence and accuracy of the business models of the EV charging market a critical factor for a company’s success. To address this issue, this paper presents a quantification framework for the business models of the core participants of the EV charging market, defining the factors that directly influence their revenues and costs and providing two sets of earnings before interest and taxes (EBIT) formulas: explicit and implicit. The explicit formulas would be useful for business analytics of the current participants of the EV charging market, while the implicit could be applied by the new entrants, to make reliable predictions based on the benchmark data. These formulas include factors that have not been previously addressed in the literature such as different prices per type of charger, the annual consumed amount of energy per charger and their utilization rate among others. Finally, this research applies the defined framework on an EBIT scenario of an archetypical charge point operator, based on real-life data. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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15 pages, 2394 KiB

Open AccessArticle

State-of-Health Estimate for the Lithium-Ion Battery Using Chi-Square and ELM-LSTM

by Jianfeng Jiang, Shaishai Zhao and Chaolong Zhang

World Electr. Veh. J. 2021, 12(4), 228; https://doi.org/10.3390/wevj12040228 - 10 Nov 2021

Cited by 6 | Viewed by 2038

Abstract

The state-of-health (SOH) estimation is of extreme importance for the performance maximization and upgrading of lithium-ion battery. This paper is concerned with neural-network-enabled battery SOH indication and estimation. The insight that motivates this work is that the chi-square of battery voltages of each [...] Read more.

The state-of-health (SOH) estimation is of extreme importance for the performance maximization and upgrading of lithium-ion battery. This paper is concerned with neural-network-enabled battery SOH indication and estimation. The insight that motivates this work is that the chi-square of battery voltages of each constant current-constant voltage phrase and mean temperature could reflect the battery capacity loss effectively. An ensemble algorithm composed of extreme learning machine (ELM) and long short-term memory (LSTM) neural network is utilized to capture the underlying correspondence between the SOH, mean temperature and chi-square of battery voltages. NASA battery data and battery pack data are used to demonstrate the estimation procedures and performance of the proposed approach. The results show that the proposed approach can estimate the battery SOH accurately. Meanwhile, comparative experiments are designed to compare the proposed approach with the separate used method, and the proposed approach shows better estimation performance in the comparisons. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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11 pages, 1832 KiB

Open AccessArticle

Parity–Time Symmetric Model and Analysis for Stable Multi-Load Wireless Power Transfer

by Zhenghao Zhu, Huan Yuan, Renjie Zhang, Aijun Yang, Xiaohua Wang and Mingzhe Rong

World Electr. Veh. J. 2021, 12(4), 226; https://doi.org/10.3390/wevj12040226 - 9 Nov 2021

Cited by 2 | Viewed by 1848

Abstract

A noticeable challenge for a multi-load wireless power transfer system is to achieve stable power transfer under a dynamic change in coupling conditions. It was proposed that the parity–time symmetric wireless power transfer (PT-WPT) system can achieve stable output efficiency for a single [...] Read more.

A noticeable challenge for a multi-load wireless power transfer system is to achieve stable power transfer under a dynamic change in coupling conditions. It was proposed that the parity–time symmetric wireless power transfer (PT-WPT) system can achieve stable output efficiency for a single receiver when tuned at the purely real eigenfrequency. However, in the case of higher order, PT symmetric systems usually cannot maintain the real eigenfrequency. To address the issue, a high-order PT-WPT model was established using coupled mode theory (CMT) theory in this paper, and the eigenfrequency of the multi-load PT-WPT system was analyzed. Here, we propose that, theoretically, the system can work at the purely real eigenfrequency by impedance matching. The transfer efficiency of the multi-load PT-WPT system when the system works at the real eigenfrequency was analyzed. The results of the numerical simulation show that the multi load PT-WPT system can maintain stable output efficiency under a dynamic change in coupling conditions. In the long run, our work provides a new possibility for the stable transmission of the multi-load wireless power transfer system. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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10 pages, 4719 KiB

Open AccessArticle

Magnetic Coupling Common Mode Conducted EMI Analysis and Improvement in a Boost Converter

by Junping He, Yujin Liu, Cong Wang and Lingling Cao

World Electr. Veh. J. 2021, 12(4), 225; https://doi.org/10.3390/wevj12040225 - 9 Nov 2021

Cited by 3 | Viewed by 1999

Abstract

Common mode (CM) electromagnetic interference (EMI) has been a difficult subject in electromagnetic compatibility (EMC) analysis and design of power converters for electric vehicles (EV) because of its complex formation mechanism and hidden propagation path. This paper studies a new mechanism of CM [...] Read more.

Common mode (CM) electromagnetic interference (EMI) has been a difficult subject in electromagnetic compatibility (EMC) analysis and design of power converters for electric vehicles (EV) because of its complex formation mechanism and hidden propagation path. This paper studies a new mechanism of CM conducted emission caused by the leakage flux of a toroidal inductor in the main circuit of a boost DC/DC converter. The stray magnetic source and the CM inducted loops are firstly identified out by simulation analysis and experiments. Then a comprehensive conducted emission circuit model including magnetic coupling parameters is built to explain this CM EMI formation mechanism. Finally, several effective magnetic coupling suppression methods are proposed and verified, such as changing the installation angle of the inductor and the shape of the magnetic core. The research results are helpful to the EMC understanding and design of power electronic converters. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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13 pages, 3477 KiB

Open AccessArticle

Battery Capacity Estimation Based on Incremental Capacity Analysis Considering Charging Current Rate

by Yiran Lin, Bo Jiang and Haifeng Dai

World Electr. Veh. J. 2021, 12(4), 224; https://doi.org/10.3390/wevj12040224 - 9 Nov 2021

Cited by 10 | Viewed by 2651

Abstract

Incremental capacity analysis (ICA) is widely used in the battery decay mechanism analysis since the features of battery incremental capacity (IC) curves are closely related to battery aging and maximum available capacity. However, the traditional ICA method to estimate battery capacity mainly focuses [...] Read more.

Incremental capacity analysis (ICA) is widely used in the battery decay mechanism analysis since the features of battery incremental capacity (IC) curves are closely related to battery aging and maximum available capacity. However, the traditional ICA method to estimate battery capacity mainly focuses on a single charging condition, and the influence of charging current on IC curves is ignored. In this paper, an adaptive capacity estimation method based on ICA considering the charging current is established. First, the charging experiments using different charging current rates under different battery aging statuses are designed and conducted. Then, the relationship between battery maximum available capacity, IC curve features, and charging current is investigated. Furthermore, the fitting method and data-driven method considering charging current are proposed and compared. Finally, the capacity estimation results prove the accuracy and adaptability of the proposed method. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 6755 KiB

Open AccessArticle

Investigation and Experimental Validation of Sideband Harmonic Vibration of IPMSM with and without Skewed Slots for EVs

by Zhenkang Feng, Daohan Wang, Chen Peng, Wentao Feng, Bingdong Wang, Junchen Li and Xiuhe Wang

World Electr. Veh. J. 2021, 12(4), 223; https://doi.org/10.3390/wevj12040223 - 9 Nov 2021

Cited by 1 | Viewed by 1735

Abstract

Due to their advantages of high power density and high efficiency, permanent magnet synchronous machines (PMSMs) are widely used in the field of electric vehicles (EVs). Vibration and noise are important indicators for evaluating the performance of PMSMs, and the skewed slot method [...] Read more.

Due to their advantages of high power density and high efficiency, permanent magnet synchronous machines (PMSMs) are widely used in the field of electric vehicles (EVs). Vibration and noise are important indicators for evaluating the performance of PMSMs, and the skewed slot method is now widely used to mitigate the torque ripple and noise of motors. In the vector control strategy, the space vector pulse width modulation (SVPWM) method produces sideband voltage harmonics with a frequency near the switching frequency. These harmonics act on the magnetic field to generate an excitation force with a frequency near the switching frequency. This paper compares and analyzes the sideband harmonic current and the exciting force of a skewed slot motor and a straight slot motor during steady-state operation. The research results show that the skewed slot method can effectively mitigate the vibration and noise caused by sideband harmonics. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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17 pages, 4275 KiB

Open AccessArticle

An Anti-Interference Control Method for an AGV-WPT System Based on UIO-SMC

by Jun Hou, Weidong Huang and Dongxiao Huang

World Electr. Veh. J. 2021, 12(4), 220; https://doi.org/10.3390/wevj12040220 - 4 Nov 2021

Cited by 1 | Viewed by 1847

Abstract

During the wireless charging of an automated guided vehicle (AGV), the output voltage is unstable due to changes in parameters such as coil mutual inductance and load resistance caused by external interferences and internal mismatches of the system. In this paper, an integral [...] Read more.

During the wireless charging of an automated guided vehicle (AGV), the output voltage is unstable due to changes in parameters such as coil mutual inductance and load resistance caused by external interferences and internal mismatches of the system. In this paper, an integral sliding mode control method based on an unknown input observer (UIO) containing predictive equations is designed to build an inductor–capacitor–capacitor-series (LCC-S) topology model for wireless power transfer (WPT). The observer designed by this method can perceive changes in the secondary resistance parameter and the mutual inductance of the primary and secondary coils. The design with the prediction equation speeds up the convergence of the observer to the true value. The observer’s compensation of the control system avoids the occurrence of integral oversaturation. The experimental results show that, based on the UIO-SMC system output, voltage can be accurately controlled to meet the requirement for a given voltage. The effect of suppressing disturbance is better than with SMC and PI control. When the system parameter changes, it has better voltage anti-interference performance and stronger ripple suppression. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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16 pages, 5071 KiB

Open AccessArticle

Finite Element Analysis-Aided Optimization of Rectangular Coil Assemblies Applied in Electric Vehicle Inductive Chargers

by Guodong Zhu and Dawei Gao

World Electr. Veh. J. 2021, 12(4), 219; https://doi.org/10.3390/wevj12040219 - 4 Nov 2021

Cited by 1 | Viewed by 1737

Abstract

Energy efficiency and leakage magnetic field (LMF) are two important issues in electric vehicle inductive chargers. In this work, the maximum achievable coil efficiency and the corresponding LMF strength are formulated as functions of system parameters, and figures of merits (FOM) are proposed [...] Read more.

Energy efficiency and leakage magnetic field (LMF) are two important issues in electric vehicle inductive chargers. In this work, the maximum achievable coil efficiency and the corresponding LMF strength are formulated as functions of system parameters, and figures of merits (FOM) are proposed for assessing the efficiency and LMF performance of the coil assembly pair. The impacts of the coil assemblies’ geometric parameters on both FOMs are examined with the aid of finite element analysis (FEA), and measures to improve the FOMs are suggested based on FEA results. A manual optimization process is conducted on a coil assembly pair. Compared with the initial design, the optimized one results in a higher DC-to-DC efficiency and lower LMF strength while consuming less copper. The performance improvement is verified by FEA results and experimental data measured on an 85 kHz electric vehicle inductive charger prototype. The key measures for coil assembly optimization are summarized. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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18 pages, 5357 KiB

Open AccessArticle

A Medium- and Long-Term Orderly Charging Load Planning Method for Electric Vehicles in Residential Areas

by Zhaoxia Xiao, Yi Zhou, Jianing Cao and Rui Xu

World Electr. Veh. J. 2021, 12(4), 216; https://doi.org/10.3390/wevj12040216 - 3 Nov 2021

Cited by 5 | Viewed by 1818

Abstract

Due to the large number of electric vehicles (EVs) connected to the distribution network of residential areas (RAs), community charging has become a major constraint. The planning of the distribution network in RAs needs to consider the orderly charging load of EVs. In [...] Read more.

Due to the large number of electric vehicles (EVs) connected to the distribution network of residential areas (RAs), community charging has become a major constraint. The planning of the distribution network in RAs needs to consider the orderly charging load of EVs. In the current study, an orderly charging planning method for the charging posts and distribution network of RAs was proposed. First, a charging load forecasting model based on the travel characteristics, charging time, and ownership of EVs in RAs was established. Then, a hierarchical orderly charging optimization method, including a distribution network layer and EV access node layer, was devised. The upper layer optimizes the distribution network. The objective function is the minimum variance of the overall load in the RA and the constraint conditions satisfy the overall charging load demand and the capacity of the distributed network. The lower layer optimizes the EV access nodes. The objective function is the minimum variance of the node access load, and the constraint conditions are to meet the regional charging load demand and the optimal power balance demand transmitted from the upper layer to the lower layer. A nonlinear optimization algorithm is employed to solve these objective functions. An IEEE 33 node example was used to obtain the orderly charging power load curves for weekdays and weekends in RAs, and the simulation results prove the effectiveness of the proposed method. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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10 pages, 8412 KiB

Open AccessArticle

Multi-System Coupling DMi Hybrid Vehicle Modeling and Its Performance Analysis Based on Simulation

by Song Li, Puxi Wang, Dong Zeng, Wenjie Peng and Liu Yang

World Electr. Veh. J. 2021, 12(4), 215; https://doi.org/10.3390/wevj12040215 - 1 Nov 2021

Cited by 3 | Viewed by 5546

Abstract

Key subsystems, such as driving resistance, component performance, and energy management strategy, determine the power performance and energy consumption of hybrid electric vehicles. Qin Plus performs excellently in fuel consumption due to its low driving resistance, high thermal efficiency of the engine, and [...] Read more.

Key subsystems, such as driving resistance, component performance, and energy management strategy, determine the power performance and energy consumption of hybrid electric vehicles. Qin Plus performs excellently in fuel consumption due to its low driving resistance, high thermal efficiency of the engine, and multi-factor multi-mode energy management strategy. This article aims to explain the outstanding energy consumption of DMi vehicles by analyzing the driving resistance, component parameters of Qin Plus and introducing the drive modes selection and vehicle energy management strategy through multi-system modeling and simulation. The ultra-low fuel consumption of 3.8 L is obtained under the NEDC driving cycle and evaluated by the corresponding experiment. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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18 pages, 10751 KiB

Open AccessArticle

Research on High Power Factor Single Tube Variable Structure Wireless Power Transmission

by Yi Yang, Xuejian Zhang, Lei Luo, Shiyun Xie and Qingshan Zhou

World Electr. Veh. J. 2021, 12(4), 214; https://doi.org/10.3390/wevj12040214 - 1 Nov 2021

Cited by 3 | Viewed by 1656

Abstract

Aiming at the problems existing in the current radio energy transmission system, we propose a wireless power transmission (WPT) system with the parallel–parallel (PP)-compensated structure. The transmitter of the transmission system adopts a separate topological structure to suppress the current shock and noise. [...] Read more.

Aiming at the problems existing in the current radio energy transmission system, we propose a wireless power transmission (WPT) system with the parallel–parallel (PP)-compensated structure. The transmitter of the transmission system adopts a separate topological structure to suppress the current shock and noise. In order to improve the efficiency of the WPT, reduce the static loss, and reduce the current oscillation loss on the power side, the input current ripple can be improved by two parallel phase-shifting methods. In this paper, two topological theories are analyzed, and the simulation and experiment results verify the correctness of these theories under both static and on-load conditions. After the final two-way phase-shift, 61.99% of the ripple is reduced. It provides a new approach for the design of WPT systems with PP structure. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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14 pages, 4298 KiB

Open AccessArticle

Research on Establishment of Vehicle Energy Distribution Model and Energy Consumption Optimization Based on Electric Hybrid System

by Peng Liang, Huatuo He, Huafang Cui and Minglang Zhang

World Electr. Veh. J. 2021, 12(4), 213; https://doi.org/10.3390/wevj12040213 - 1 Nov 2021

Viewed by 1827

Abstract

In order to improve the adaptability and accuracy of the system average efficiency model in energy consumption analysis of working conditions, this paper presents a vehicle energy distribution model based on the layout and powertrain operation features of the electric hybrid system, and [...] Read more.

In order to improve the adaptability and accuracy of the system average efficiency model in energy consumption analysis of working conditions, this paper presents a vehicle energy distribution model based on the layout and powertrain operation features of the electric hybrid system, and presents a vehicle energy consumption optimization method for control strategy and hardware quality optimization based on the guidance of the energy distribution model. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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14 pages, 3846 KiB

Open AccessArticle

An Adaptive Adjustment Method of Equivalent Factor Considering Speed Predict Information

by Bingzhan Zhang, Qinglong Meng, Juncheng Wu and Yaoyao Ni

World Electr. Veh. J. 2021, 12(4), 211; https://doi.org/10.3390/wevj12040211 - 26 Oct 2021

Cited by 3 | Viewed by 1786

Abstract

Although the energy management strategies at present have achieved a good effect, they still have their limitations, so there is still room for further improvement to improve the fuel economy of hybrid electric vehicles (HEV). This paper proposes an adaptive equivalent consumption minimization [...] Read more.

Although the energy management strategies at present have achieved a good effect, they still have their limitations, so there is still room for further improvement to improve the fuel economy of hybrid electric vehicles (HEV). This paper proposes an adaptive equivalent consumption minimization strategy (ECMS) based on speed prediction, which can distribute power more reasonably and improve the power balance and fuel economy. The driving speed reflects the operation of the road and driver during the driving process. Under the motor assisted energy management control strategy, knowing all working condition information in advance can improve the battery power use planning to a certain extent and reduce the fuel consumption during the whole driving process by adjusting parameters. In this paper, a novel adaptive adjustment method for the equivalent factor (EF) of the ECMS based on future information is proposed. In this paper, a novel speed-prediction method combined with wavelet packet transformation (WPT) and a radial basis function neural network (RBF-NN) is proposed to realize accurate vehicle speed prediction. Then, the optimal equivalent factor under the state of charge (SOC) constraint is calculated by using the predicted speed. Simulation studies are conducted to verify the effectiveness of the proposed adjustment method for the EF compared to a commonly adjustment method from SOC balance and economic viewpoints. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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14 pages, 2279 KiB

Open AccessArticle

Load Transfer Path Search and Its Evaluation between Networks in Consideration of the Mobile Energy Storage of Electric Vehicles

by Dongyu Mao, Xueliang Huang, Zhong Chen, Yang Lv, Jiang Tian and Zexin Yang

World Electr. Veh. J. 2021, 12(4), 210; https://doi.org/10.3390/wevj12040210 - 25 Oct 2021

Cited by 1 | Viewed by 1657

Abstract

Load transfer is an important way of restoring a power supply after equipment failure or maintenance. However, current methods ignore cooperation between networks and users, and they also fail to take into account the vehicle-to-grid (V2G) potential of electric vehicles (EVs). In this [...] Read more.

Load transfer is an important way of restoring a power supply after equipment failure or maintenance. However, current methods ignore cooperation between networks and users, and they also fail to take into account the vehicle-to-grid (V2G) potential of electric vehicles (EVs). In this paper, a load transfer scheme between transmission and distribution networks is proposed, considering the mobile energy storage capacities of electric vehicles. First, the mobility characteristic and the available discharge capacity of EVs are analyzed on the basis of the parking generation rate. Then, the breadth-first algorithm is used to search the load transfer paths within and between stations, and an edge matching method is proposed to realize the conversion between networks with different voltage levels. Lastly, the optimal combination weighting method was adopted to combine subjective and objective index weights and to evaluate power supply paths. The effectiveness of the proposed scheme is validated in a case composed of an IEEE 30-node network and an IEEE 57-node network, with four typical scenarios. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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13 pages, 7494 KiB

Open AccessArticle

Hybrid Energy Storage Management Strategy for Electric Propulsion Aircraft Based on Three-Step Power Distribution

by Hang Li, Taike Yao, Xuan Zhang, Feifei Bu and Luhui Weng

World Electr. Veh. J. 2021, 12(4), 209; https://doi.org/10.3390/wevj12040209 - 23 Oct 2021

Cited by 2 | Viewed by 2053

Abstract

To solve the problem of severe DC bus voltage fluctuations caused by frequent changes in the distributed electric propulsion aircraft load, and to further optimize the size and life of the hybrid energy storage system (HESS), this paper proposes a method based on [...] Read more.

To solve the problem of severe DC bus voltage fluctuations caused by frequent changes in the distributed electric propulsion aircraft load, and to further optimize the size and life of the hybrid energy storage system (HESS), this paper proposes a method based on three-step power distribution (TSPD). This strategy realizes the reasonable distribution of battery and supercapacitor power by using a low pass filter. Through the introduction of a supercapacitor state-of-charge (SOC) automatic recovery control and maximum power value dynamic limit strategy, the size of the HESS is optimized, and the service life of the energy storage device is extended. Finally, simulation and experiment platform are built to prove the effectiveness of the proposed strategy. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 3028 KiB

Open AccessArticle

Implementation of Equilibrium Strategy Aiming at Throughput Maximization of Series Battery Pack

by Rui Cao, Xinhua Liu, Zhengjie Zhang, Mingyue Wang, Hanchao Cheng, Xinlei Gao, Xiaoyu Yan and Shichun Yang

World Electr. Veh. J. 2021, 12(4), 208; https://doi.org/10.3390/wevj12040208 - 22 Oct 2021

Viewed by 1676

Abstract

In the operation process of a power battery pack, the inconsistency among lithium-ion cells may seriously restrict the pack’s capacity, power capability and lifetime, which may bring hidden danger to the use of electric vehicles. Equalization management systems (EMSs) are crucial to alleviate [...] Read more.

In the operation process of a power battery pack, the inconsistency among lithium-ion cells may seriously restrict the pack’s capacity, power capability and lifetime, which may bring hidden danger to the use of electric vehicles. Equalization management systems (EMSs) are crucial to alleviate such inter-cell inconsistency, whose performance such as accuracy and stability, mainly depends on the setting of equalization control strategies. This paper proposes an equalization strategy aimed at throughput maximization of series battery in the whole life cycle based on Model Prediction Control (MPC). In this paper, a Mean-plus-difference model (M+D) model is selected as the series battery model and the parameters are identified by Recursive Least Squares (RLS). Based on the model predictive control theory, the control model of series battery pack is established and the objective function of maximizing the throughput in the whole life cycle is derived. At the end of the paper, the simulation results show that the proposed equalization strategy can achieve greater life cycle throughput compared with the traditional SOC equalization strategy, which verifies the guiding significance of the equilibrium strategy proposed in this paper. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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11 pages, 5248 KiB

Open AccessArticle

Challenges in Grid Integration of Electric Vehicles in Urban and Rural Areas

by Jakob Gemassmer, Carolin Daam and Ricardo Reibsch

World Electr. Veh. J. 2021, 12(4), 206; https://doi.org/10.3390/wevj12040206 - 21 Oct 2021

Cited by 18 | Viewed by 4183

Abstract

The ramp-up of battery electric vehicles (BEVs) could lead to severe grid issues but also enables flexibility. This paper provides a better understanding of the challenges and potentials of integrating BEVs in power grids. Three charging strategies were modelled on four use cases [...] Read more.

The ramp-up of battery electric vehicles (BEVs) could lead to severe grid issues but also enables flexibility. This paper provides a better understanding of the challenges and potentials of integrating BEVs in power grids. Three charging strategies were modelled on four use cases and six low-voltage grids for urban and rural areas. Especially in rural areas, where many cars charge at home overnight, the charging strategy significantly affects grid issues. Purely market-oriented strategies can lead to high load peaks and thus to transformer and line overloading, while even a relatively simple, balanced charging strategy can significantly reduce grid issues. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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15 pages, 3390 KiB

Open AccessArticle

Operation Strategy of Parking Lots Integrated with PV and Considering Energy Price Tags

by Zexin Yang, Xueliang Huang, Shan Gao, Qi Zhao, Hongen Ding, Tian Gao, Dongyu Mao and Rui Ye

World Electr. Veh. J. 2021, 12(4), 205; https://doi.org/10.3390/wevj12040205 - 21 Oct 2021

Cited by 6 | Viewed by 1947

Abstract

In recent years, the orderly charging of electric vehicles (EVs) in commercial parking has become a meaningful research topic due to the increasing number of EVs, especially for parking lots close to workplaces and serving fixed users. In this paper, a parking lot [...] Read more.

In recent years, the orderly charging of electric vehicles (EVs) in commercial parking has become a meaningful research topic due to the increasing number of EVs, especially for parking lots close to workplaces and serving fixed users. In this paper, a parking lot energy management system integrated with energy storage system (ESS) and photovoltaic (PV) system is established. The concept of energy price tag (EPT) is introduced to define the price of all energy storage devices, and the priority order between PV, ESS, EVs, and power grid is established. Taking the minimization of charging cost as the optimization objective, the charging plans of ESS, EVs, and buildings are optimized considering the constraints of EVs user demand and PV power. By comparing the simulation results of four cases, it is proven that this strategy can reduce the charging cost and improve the consumption rate of PV. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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10 pages, 2715 KiB

Open AccessArticle

Battery Pack State of Health Prediction Based on the Electric Vehicle Management Platform Data

by Xiaoyu Li, Tengyuan Wang, Chuxin Wu, Jindong Tian and Yong Tian

World Electr. Veh. J. 2021, 12(4), 204; https://doi.org/10.3390/wevj12040204 - 20 Oct 2021

Cited by 7 | Viewed by 1971

Abstract

In electric vehicle technologies, the state of health prediction and safety assessment of battery packs are key issues to be solved. In this paper, the battery system data collected on the electric vehicle data management platform is used to model the corresponding state [...] Read more.

In electric vehicle technologies, the state of health prediction and safety assessment of battery packs are key issues to be solved. In this paper, the battery system data collected on the electric vehicle data management platform is used to model the corresponding state of health of the electric vehicle during charging and discharging processes. The increment in capacity in the same voltage range is used as the battery state of health indicator. In order to improve the modeling accuracy, the influence of ambient temperature on the capacity performance of the battery pack is considered. A temperature correction coefficient is added to the battery state of health model. Finally, a double exponential function is used to describe the process of battery health decline. Additionally, for the case where the amount of data is relatively small, model migration is also applied in the method. Particle swarm optimization algorithm is used to calibrate the model parameters. Based on the migration battery pack model and parameter identification method, the proposed method can obtain accurate battery pack SOH prediction result. The method is simple and easy to perform on the electric vehicle data management platform. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 3335 KiB

Open AccessArticle

Research on Metal Foreign Object Detection of Electric Vehicle Wireless Charging System Based on Detection Coil

by Tao Meng, Linlin Tan, Ruying Zhong, Huiru Xie and Xueliang Huang

World Electr. Veh. J. 2021, 12(4), 203; https://doi.org/10.3390/wevj12040203 - 19 Oct 2021

Cited by 9 | Viewed by 2433

Abstract

Due to the open structure of wireless charging systems, foreign objects are inevitably involved. In the process of energy transfer, the intervention of metal foreign objects will cause the system to deviate from the normal operating point and even cause safety accidents. Therefore, [...] Read more.

Due to the open structure of wireless charging systems, foreign objects are inevitably involved. In the process of energy transfer, the intervention of metal foreign objects will cause the system to deviate from the normal operating point and even cause safety accidents. Therefore, metal foreign objects detection (MOD) technology is of considerable importance. In this paper, a metal foreign object detection system of a wireless power transfer (WPT) system based on the symmetrical detection coil was designed, and a MOD method based on frequency scanning is proposed. The coil size of the WPT system was designed based on SAE-J2954 standard. In addition, the suitable detection coil was installed at the transmitting coil. The system model was established in ANSYS simulation software, and 5 cm × 5 cm copper sheet and iron sheet were used as the metal to be detected. The result shows that the self-induction of the detection coil at the position of the foreign object can achieve a fluctuation of 52.46% and −34.72%, and the resonant frequency of the detection system is offset by 24.7% and −18.82%, respectively. Finally, the experimental platform of MOD system was built, and the effectiveness of the system was verified. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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12 pages, 1905 KiB

Open AccessArticle

Safety Design and Engineering Solution of Fuel Cell Powered Ship in Inland Waterway of China

by Lijian Chen and Wenfeng Guan

World Electr. Veh. J. 2021, 12(4), 202; https://doi.org/10.3390/wevj12040202 - 19 Oct 2021

Cited by 5 | Viewed by 3170

Abstract

From the perspective of risk control, when hydrogen fuel and fuel cells are used on ships, there is a possibility of low-flash fuel leakage, leading to the risk of explosion. Since the fuel cell space (cabin for fuel cell installations) is an enclosed [...] Read more.

From the perspective of risk control, when hydrogen fuel and fuel cells are used on ships, there is a possibility of low-flash fuel leakage, leading to the risk of explosion. Since the fuel cell space (cabin for fuel cell installations) is an enclosed space, any small amount of leakage must be handled properly. In ship design, area classification is a method of analyzing and classifying the areas where explosive gas atmospheres may occur. If the fuel cell space is regarded as a hazardous area, all the electrical devices inside it must be explosion-proof type, which will make the ship’s design very difficult. This paper takes a Chinese fuel cell powered ship as an example to analyze its safety. Firstly, the leakage rates of fuel cell modules, valves, and connectors are calculated. Secondly, the IEC60079-10-1 algorithm is used to calculate the risk level of the fuel cell space. Finally, the ship and fuel cells are optimized and redesigned, and the risk level of the fuel cell space is recalculated and compared. The result shows that the optimized fuel space risk level could be reduced to the level of the non-hazardous zone. Full article

(This article belongs to the Special Issue Towards Intelligent E-Mobility—Selected Papers from The 34th International Electric Vehicles Symposium and Exhibition (Nanjing, China))

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