Multi-Objective Optimal Sizing of Hybrid Energy Storage ... - IEEE Xplore

This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TVT.2017.2762368, IEEE Transactions on Vehicular Technology

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regulate the UC current flow to the DC bus at the command of the control unit. The gap between the power demands from the EM inverter and the UC bank output is offset by the battery bank. The electric motor not only works to provide the driving torque in propulsion mode, but also functions as a generator to charge the ultracapacitor bank by regenerative braking in deceleration mode. The EM efficiency and torque limits are illustrated in Fig. 3. It is worth mentioning that the stored energy in the ultracapacitor bank can be harnessed in future acceleration or hill-climbing conditions to fulfil the peak power demands. This is a typical torque/speed curve for a hybrid or electric vehicle and it exhibits the characteristic narrow constant torque region before entering into an extended constant power (or field weakening) region [30]. The transmission reduces the speed with a fixed gear ratio while maintaining good efficiency under different working conditions.

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Fig. 4. Battery and ultracapacitor model.

Fig. 5. UDDS driving cycle. H(z) x(n)

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Fig. 6. Harr wavelet decomposition and reconstruction.

while the SOH deteriorates more significantly with increasing c-rate. III. POWERTRAIN MODELLING A. Powertrain Configuration There are three main HESS configurations that are commonly used [29]. They are passive, semi-active and fullyactive HESS, each with strengths and limitations. Generally, the passive HESS connects the battery and UC banks in parallel, and directly couples to the load without any electronic converters. The voltage of the ultracapacitor bank is tied to the battery voltage, which usually exhibits small changes during operation. This means that the power potential of the ultracapacitors may not be well utilized because of the inherent relationship between the voltage and its delivered energy. The fully active HESS gives the best performance by employing two DC-DC converters; this increases the complexity and leads to higher manufacture cost. The semi-active HESS seems to be a good trade-off between performance and circuit complexity; it uses only one DC-DC converter and relatively simple control circuitry. A series-connected ultracapacitor configuration in a semi-active hybrid system is chosen in this paper because it permits the voltage of the ultracapacitor bank to vary over a large range, which contributes to a better use of the stored energy and power. An example electric vehicle is chosen in this study with its powertrain illustrated in Fig. 2. The basic vehicle parameters are listed in Table II. A DC-DC converter is placed between the ultracapacitor bank and the DC bus, and used to

B. Battery modeling Many battery models have been developed for different purposes in the literature [31][32][33]. Generally, high-fidelity models have high modelling accuracy but bring with heavy computation. They are more suitable for enabling energy management development. In comparison, this study focuses on the optimal sizing issue that concerns more with computation efficiency over modelling accuracy. Thus, the Rint model, as shown in Fig. 4, is used here to represent the battery dynamics owing to its simplicity and acceptable accuracy. In order to reach the required voltage level for motor drive and minimal capacity for ensuring certain driving range, a battery bank composed of nbp parallel strings with each containing nbs series connected cells is deployed in the example electric vehicle. It is worth noting that the parallel connections of cell strings also facilitate to enhancing the power delivery capability of the battery bank. The main specifications of the battery cell are shown in Table III, while the main parameters of the battery pack are derived as QBATT  nbs nbp QB _ cell  nbs RB _ cell  (7)  RBATT  nbp   V  BATT  nbsVB _ cell where QBATT and VBATT denote the capacity and the terminal voltage of the battery bank, nbs denotes the number of series connected battery cell, nbp denotes the number of parallel connected battery cell stings, RB_cell is the battery cell resistance, QB_cell is the nominal cell capacity and VB_cell is the battery cell nominal voltage. C. Ultracapacitor modeling In contrast to the high energy density of batteries, UCs have high power density, low internal resistance, wide temperature operation window and excellent recyclability. The UC degradation is ignored in this study since the cycle-life of UCs can reach the magnitude of millions of recharges without notable performance deterioration. Owing to the low energy density characteristic of UCs, UC cells are threaded to form UC bank with the purpose of storing

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0) is the position parameter that

A discrete waveform transform (DWT) is used to decompose the discretized signal into different resolutions based on the scale factor. The DWT and its inverse are  1  t   W ( , s)   x(t )    dt ,  (13) s  s 

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REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < [25] Fuller TF, Doyle M, Newman J. “Simulation and optimization of the dual lithium ion insertion cell,” J. Electrochem. Soc., vol.141, no.1, pp.1-10, Jan. 1994. [26] S. Ebbesen, P. Elbert, L. Guzzella, “Battery state-of-health perceptive energy management for hybrid electric vehicles,” IEEE Trans. Veh. Technol., vol. 61, no. 7, pp. 2893-2900, Sept. 2012. [27] J. Wang, P. Liu, J. Hicks-Garner, E. Sherman, S. Soukiazian, M. Verbrugge, H. Tataria, J. Musser, P. Finamore, “Cycle-life model for graphite-LiFePO4 cells,” J. Power Sources, vol. 196, no. 8, pp. 3942-3948, Apr. 2011. [28] http://www.maxwell.com/images/documents/K2Series_DS_1015370_5_ 20141104.pdf [29] Z. Song, H. Hofmann, J. Li, X. Han, X. Zhang, and M. Ouyang, “A comparison study of different semi-active hybrid energy storage system topologies for electric vehicles,” J. Power Sources, vol. 274, pp. 400-411, Jan. 2015. [30] D. G. Dorrell, M.-F. Hsieh and A. M. Knight, “Alternative rotor designs for high performance brushless permanent magnet machines for Hybrid Electric Vehicles,” IEEE Trans. on Magn., vol. 48, no. 2,pp: 835-838, Feb. 2012. [31] J. Li, M. S. Mazzola, “Accurate battery pack modeling for automotive applications,” J. Power Sources, vol. 237, pp. 215-228, Sep. 2013. [32] M. S. Mazzola, M. Shahverdi, “Li-ion Battery Pack and Applications,” Rechargeable Batteries, pp. 455-476, 2015. [33] J. Li, M. S. Mazzola, J. Gafford, B. Jia, M. Xin, “Bandwidth based electrical-analogue battery modeling for battery modules,” J. Power Sources, vol. 28, no. 2, pp.331-340, Nov. 2012. [34] M. Shahverdi, M. S. Mazzola, Q. Grice, M. Doude, “Bandwidth-based control strategy for a series HEV with light energy storage system,” IEEE Trans. Veh. Technol., vol. 66, no. 2, pp. 1040-1052, Feb. 2017. [35] S. Dusmez and A. Khaligh, “A supervisory power-splitting approach for a new ultracapacitor-battery vehicle deploying two propulsion machines,” IEEE Trans. Ind. Informat., vol. 10, no. 3, pp. 1960-1971, Aug. 2014. [36] S. M. Ahmedaand M. A Zahhad. A new hybrid algorithm for ECG signal compression based on the wavelet transformation of the linearly predicted error. Med. Eng. Phys., vol. 23, no. 2, pp: 117-216, Apr. 2001. [37] O. Erdinc, B. Vural, M. Uzunoglu, and Y. Ates, “Modeling and analysis of an FC/UC hybrid vehicular power system using a wavelet-fuzzy logic based load sharing and control algorithm,” Int. J. Hydrogen Energ., vol. 34, no. 12, pp. 5223-5233, Jun. 2009. [38] C. Capilla, “Application of the Haar wavelet transform to detect microseismic signal arrivals,” J. Appl. Geophys., vol. 59, no. 1, pp. 36-46, May 2006. [39] K. Deb, A. Pratap, S. Agarwal, and T. Meyarivan, “A fast and elitist multiobjective genetic algorithm: NSGA-II,” IEEE Trans. Evolut. Comput., vol. 6, no. 2, pp. 182-197, Apr. 2002. Copyright (c) 2015 IEEE. Personal use of this material is permitted. However, permission to use this material for any other purposes must be obtained from the IEEE by sending a request to [email protected].

Lei Zhang (S’12-M’16) received the Ph.D. degree in mechanical engineering from Beijing Institute of Technology, Beijing, China, in 2010. He is now an assistance professor at the School of Mechanical Engineering, Beijing Institute of Technology. His research interest includes ultracapacitor and battery modeling and state estimation, energy management development for hybrid energy storage system for electric vehicle application.

Xiaosong Hu (S’11–M’13) received the Ph.D. degree in Automotive Engineering from Beijing Institute of Technology, China, in 2012.

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He did scientific research and completed the Ph.D. dissertation in Automotive Research Center at the University of Michigan, Ann Arbor, USA, between 2010 and 2012. He is currently a professor at the Department of Automotive Engineering, Chongqing University, Chongqing, China. He was a postdoctoral researcher at the Department of Civil and Environmental Engineering, University of California, Berkeley, USA, between 2014 and 2015, as well as at the Swedish Hybrid Vehicle Center and the Department of Signals and Systems at Chalmers University of Technology, Gothenburg, Sweden, between 2012 and 2014. He was also a visiting postdoctoral researcher in the Institute for Dynamic systems and Control at Swiss Federal Institute of Technology (ETH), Zurich, Switzerland, in 2014. His research interests include modeling and control of alternative-energy powertrains and energy storage systems. Dr. Hu was a recipient of Beijing Best Ph.D. Dissertation Award in 2013.

Zhenpo Wang (M’11) received the Ph.D. degree in automotive engineering from Beijing Institute of Technology, Beijing, China, in 2005. He is currently a Professor with Beijing Institute of Technology, and the Associate Director of Collaborative Innovation Center for Electric Vehicles in Beijing and National Engineering Laboratory for Electric Vehicles. His current research interests include pure electric vehicle integration, packaging and energy management of battery system and charging station design. Prof. Zhenopo Wang has been the recipient of numerous awards including the second National Prize for Progress in Science and Technology and the first Prize for Progress in Science and Technology from the Ministry of Education, China and the second Prize for Progress in Science and Technology from Beijing Municipal, China. He has published 4 monographs and translated books as well as more than 60 technical papers. He also holds more than 10 patents.

Junjun Deng (S’13–M’14) received his B.S., M.S. and Ph.D. degrees in electrical engineering from Northwestern Polytechnial University, Xi’an, China, in 2008, 2011 and 2015, respectively. From 2011 to 2014, he was a visiting scholar with the Department of Electrical and Computer Engineer, University of Michigan, Dearborn. In 2016, he joins the Faculty of Automotive Engineering, Beijing Institute of Technology, Beijing, China. His research interests include wireless power transfer, resonant power conversion and high performance battery chargers for electric vehicles.

David Dorrell (M 95, SM 08) is a native of St Helens, UK, and has a BEng (Hons) degree in Electrical and Electronic Engineering from The University of Leeds (1988), MSc degree from The University of Bradford in Power Electronics Engineering (1989) and PhD degree from The University of Cambridge in Engineering (1993). He has held lecturing positions with The Robert Gordon University and The University of Reading. He was a Senior Lecturer with The University of Glasgow, UK, for several years. In 2008 he took up a post as Senior Lecturer with The University of Technology Sydney, Australia, and he was promoted to Associate Professor in 2009. He is also an Adjunct Associate Professor with The National Cheng Kung University, Taiwan. In 2015 he took up a post as Professor of Electrical Machines at the University of KwaZulu-Natal, Durban, South Africa. He research interests cover the design and analysis of various electrical machines and also renewable energy systems. He has authored or co-authored 100 journal papers and over 250 conference papers as well as coauthored a book. He is a Chartered Engineer in the UK and a Fellow of the Institution of Engineering and Technology.


