Design and Application of Flywheel–Lithium Battery Composite Energy System for Electric Vehicles

Sun Binbin,Xie Mengxue,Li Bo,Wang Pengwei,Gao Song 한국자동차공학회 2024 International journal of automotive technology Vol.25 No.1

For diff erent types of electric vehicles, improving the effi ciency of on-board energy utilization to extend the range of vehicle is essential. Aiming at the effi ciency reduction of lithium battery system caused by large current fl uctuations due to sudden load change of vehicle, this paper investigates a composite energy system of fl ywheel–lithium battery. First, according to the design requirements of vehicle performance, the essential parameters of the hybrid energy storage system are designed using CPE function. Then, based on the vehicle dynamics and operating principle of the hybrid energy system, a mathematical model for performance analysis of the hybrid energy electric vehicle is established. Finally, energy management strategy for the hybrid energy system is designed with the use of wavelet algorithm. Research results show signifi cant improvement of the storage system effi ciency. Specially, compared with the original scheme, owing to the fl ywheel battery, the maximum current and discharge rate of the lithium battery are reduced by 6.55% and 4.76% under WLTC working condition. Meanwhile, the average current is decreased by 14.93%. Furthermore, the average effi ciency of lithium battery is improved by 3.07%. The overall effi ciency of energy storage system is increased by 2.01%.

SYSTEM POWER LOSS OPTIMIZATION OF ELECTRIC VEHICLE DRIVEN BY FRONT AND REAR INDUCTION MOTORS

Binbin Sun,Song Gao,Chao Ma,Junwei Li 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.1

Power loss optimization aiming at the high-efficiency drive of front-and-rear-induction-motor-drive electric vehicle (FRIMDEV) as an effective way to improve energy efficiency and extend driving range is of high importance. Different from the traditional look-up table method of motor efficiency, power loss optimization of the dual- motor system based on the loss mechanism of induction motor (IM) is proposed. First of all, based on the power loss characteristic of FRIMDEV from battery to wheels, the torque distribution optimization model aiming at the minimum system power loss is put forward. Secondly, referring to d-q axis equivalent model of IM, the power loss functions of the dual-IM system are modeled. Then, the optimal torque distribution coefficient (βo) between the two IMs is derived, and the theoretical switching condition (Tsw) between the single- and dual-motor-drive mode (SMDM and DMDM) is confirmed. Finally, a dual-motor test platform is developed. The derived torque distribution strategy is verified. The influence of motor temperature on βo and Tsw are tested, and the correction models based on temperature difference are proposed. Based on the system power loss analysis, it can be confirmed that, under low load conditions, the SMDM takes priority over the DMDM, and the controller of the idling motor should be shut down to avoid the additional excitation loss. While under middle to high load conditions, even torque distribution (βo = 0.5) is preferred if the temperature difference between the two IMs is small; otherwise, βo should be corrected based on dual-motor temperatures. The theoretical Tsw derived without dealing with temperature difference is a function only of motor speed, while temperature difference correction of it should be conducted in actual operations based on motor resistance changing with temperature.

Effects of illumination time on biological community of algal-bacterial granules and lipid content

Limeng Xi,Wenli Huang,Binbin Sun,Fansheng Meng,Shiguo Gu 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.6

Synthetic wastewater was used to culture granular sludge for 21 weeks at three sequencing batch reactor activated sludge process (SBR) under different photoperiods. The growth of algae changed granular oxygen distribution, which affected the composition of microbial communities. Different photoperiods were able to alter the formation of granular sludge and the microbial community granules. In short photoperiod (12 h/d) sludge could generate symbiotic algae-bacteria granules in the SBR. By contrast, the long photoperiod (24 h/d) promotes the growth of algae and Ascomycota early, and then inhibits algae, especially chlorophyta (only 1.18%). In the end, algae-bacteria-fungi granules were formed in long photoperiod (LP). By GC-MS and model calculation, the lipid content of algae-bacteria granules was 33.71% more than that of pure aerobic granular sludge. However, the proportion of unsaturated fatty acids in algae-bacteria granules was as high as 43%, resulting in the quality of biodiesel prepared from algae-bacteria granule being slightly worse than that prepared from pure aerobic granular sludge. But both of them were better than biodiesel prepared from pure algae. The biodiesel content of algae-bacteria granule in short photoperiod (SP) and LP were 68.79 and 70.66 mg/g, respectively, which was better than that of pure aerobic particles (52.30 mg/g). Therefore, the formation of algae-bacteria granules is an effective way to remove nutrients and reduce harvesting costs.

Improved Mechanical Properties of Friction Stir Welded 1500 MPa Martensitic Steel Joints with Additional Water Cooling

Shuhao Zhu,Pengcheng Zhu,Binbin Wang,Liang Zhang,Yufeng Sun,Shaokang Guan 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.1

This study proposes a method to improve the mechanical strength of martensitic welded joints by minimizing the effect ofmartensitic tempering. The high-strength martensitic steel plate exhibiting a tensile strength of 1500 MPa was successfullyjoined in this study utilizing additional water-cooling by friction stir welding (FSW) technique. Concurrently, conventionalair-cooled welded joints were produced utilizing identical welding parameters for comparison. Notwithstanding the macrostructureof both FSW joints was similar, the air-cooled joint contained a larger stir zone (SZ) and wider heat-affectedzone (HAZ). The air-cooled joint SZ exhibited a microstructure featuring coarse martensite, while the water-cooled jointSZ displayed a microstructure consisting of fine martensite. The degree of self-tempering of the martensite in the HAZ wassignificantly reduced, together with fewer and finer carbide particles than in the HAZ of air-cooled joints, by applying watercooling. The tensile test results indicated that the water-cooled FSW joint showed a significant improvement (23.6%) inultimate tensile strength compared to its air-cooled counterparts.

Measured and investigated nonlinear dynamics parameters on bolted flange joints of combined rotor

Tao Li,Dongjian Yang,Binbin Zhao,Qingchao Sun,Junzhou Huo,Wei Sun 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.5

The complex micro-slip phenomenon of the contact interface will lead to the nonlinear stiffness of the connection structure, as well as the structural damping and energy dissipation. As the most important connection structure of the combination rotor, the mechanical properties of bolted flange joint interface are needed in the dynamic analysis of the combined rotor. Therefore, it is urgent to model and test the friction contact interface in the nonlinear dynamic analysis of rotor. In this paper, two sets of mechanical characteristics test system were built to test the dynamic parameters of tangential and bending directions of the bolted flange joint interface. Then, the mechanical behavior and the change regularities of dynamics parameters were studied under different external excitation, bolt distribution and tightening torque. The results show that once the bolt preload is above the rated torque, stiffness softening behavior is not significant; and then the tangential stiffness of the joint interface tends to be stable, with the variation range of 8.08~8.96e8 N/m; the equivalent bending stiffness coefficient is about 3.38~3.83e6 N·m/rad. With the decrease of bolt preload, the external excitation and the number of bolts have a significant effect on the stiffness reduction of the joint. Finally, the change interval of the dynamics parameters of the interface obtained by the experiment provide basis for the uncertainty dynamic analysis and optimization of the rotor.

Dynamic modeling of a high-speed over-constrained press machine

Yejian Li,Yu Sun,Binbin Peng,Fengfeng Hu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.7

This paper presents a study on the dynamic modeling of a high-speed over-constrained press machine. The main contribution of the paper is the development of an efficient approach to perform the dynamic analysis of a planner over-constrained mechanism. The key idea is the establishment of a more general methodology, which is to gain a deformation compatibility equation for the over-constrained mechanism on the basis of the deformation compatibility analysis at each position of the mechanisms. And this equation is then used together with the force/moment equilibrium equations obtained by the D’Alembert principle to form a total equation for the dynamics of the over-constrained mechanism. The approach is applied to a particular press machine to validate the effectiveness of the approach, and in the meantime to provide some useful information for the improvement of the design of this press machine.

Elastic dynamic research of high-speed multi-link precision press considering structural stiffness of rotation joints

Fengfeng Hu,Yu Sun,Binbin Peng 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.10

An elastic dynamic model of high-speed multi-link precision press considering structural stiffness of rotation joints was established by the finite element method. In the finite element model, rotation joint was established by four bar elements with equivalent stiffness, and connected link was established by beam element. Then, the elastic dynamics equation of the system was established, and modal superposition method was used to solve the dynamic response. Compared with the traditional elastic dynamic model with perfect constraint of the rotation joints, the elastic dynamic response value of the improved model is larger. To validate the presented new method of elastic dynamics analysis with stiffness of rotation joints, a related test of slider Bottom dead center (BDC) position in different speed was designed. The test shows that the model with stiffness of rotation joints is more reasonable. So it provides a reasonable theory and method for dynamic characteristics research of sucha multi-link machine.

All-fiber mode-group-selective photonic lantern using graded-index multimode fibers

Huang, Bin,Fontaine, Nicolas K.,Ryf, Roland,Guan, Binbin,Leon-Saval, Sergio G.,Shubochkin, R.,Sun, Y.,Lingle, R.,Li, Guifang The Optical Society 2015 Optics express Vol.23 No.1

<P>We demonstrate the first all-fiber mode-group-selective photonic lantern using multimode graded-index fibers. Mode selectivity for mode groups LP(01), LP(11) and LP(21)+LP(02) is 20-dB, 10-dB and 7-dB respectively. The insertion loss when butt coupled to multimode graded-index fiber is below 0.6-dB. The use of the multimode graded-index fibers in the taper can significantly reduce the adiabaticity requirement.</P>

Optimization method of vehicle handling stability based on response surface model with D-optimal test design

Bo Li,Wenqing Ge,Dechuan Liu,Cao Tan,Binbin Sun 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.6

In order to improve the handling stability of a vehicle, an optimization method of vehicle handling stability based on D-optimal test design was proposed in this paper. The multibody dynamic model was established and verified by experiments. On this basis, a response surface model was established based on D-optimal test design. An improved genetic-particle swarm algorithm was used to optimize the vehicle handling stability. The general evaluation score of vehicle handling stability was taken as the optimization objective. The vehicle structural parameters, tire and spring characteristics were regarded as design variables. The results showed that the multi-body dynamic model was accurate. After optimization, the general evaluation score of vehicle handling stability increased by 8.98 %; the score of the steering returnability and steady static circular test was increased by 20.43 % and 27.31 %, respectively. Then from the sensitivity of the optimization variables to the stability of the vehicle's handling, the rear wheel lateral stiffness has the greatest impact on it, with a sensitivity of 86.9 %; the wheelbase has the smallest impact on it, with a sensitivity of -3.39 %, which can be reduced in future optimization variable to improve design efficiency.

Electrospun SrO-Incorporated Nanofiber Membranes for Biomedical Applications

Zhe Chen,Jitao Fan,Yangfan Ding,Yunlong Zhang,Ahmed I. Abd‑Elhamid,Jinglei Wu,Binbin Sun 한국섬유공학회 2023 Fibers and polymers Vol.24 No.11

Bioactive ceramics have gained increasing interest in biomedical applications. Strontium (Sr)-based ceramics show unique bioactivity in stimulating cell proliferation and migration and promoting angiogenesis. Incorporation of bioactive ceramics into nanofibers represents a facile approach to alter the material properties of electrospun nanofiber membranes. Herein, we prepared SrO-incorporated nanofiber membranes by electrospinning and investigated the effects of SrO particles on the physicochemical properties and cytocompatibility of these membranes. Our results indicate that simple one-stream electrospinning could smoothly introduce SrO particles into poly(L-lactic acid) (PLA)/gelatin nanofibers. SrO-incorporated membranes showed significantly improved wettability but became brittle compared with PLA/gelatin nanofiber membranes. Cells differentially responded to SrO-incorporated membranes: endothelial cells showed greater cell area and coverage on SrO-incorporated membranes; in contrast, fibroblasts were inhibited on these membranes. These findings suggest that SrO-incorporated membranes might find opportunities in specific biomedical applications in which pro-angiogenesis and antiadhesion are simultaneously demanded.