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Step by Step Conversion of ICE Motorcycle to a BEV Configuration

Wayne State University-Matthew D. Lawrence, Saeed Siavoshani
  • Technical Paper
  • 2020-01-1436
To be published on 2020-04-14 by SAE International in United States
With the mass movement toward electrification and renewable technology, the scope of innovation of electrification has gone beyond the automotive industry into areas such as electric motorcycle applications. This paper provides a discussion of the methodology and complexities of converting an internal combustion motorcycle to an electric motorcycle. In developing this methodology, performance goals including, speed limit, range, weight, charge times, as well as riding styles will be examined and discussed. Based on the goals of this paper, parts capable of reaching the performance targets are selected accordingly. Documentation of the build process will be presented along with the constraints, pitfalls, and difficulties associated with process of the project. The step-by-step methodology that is developed can be used as a guideline for future build and can be enhanced as necessary. During the development & conversion process, the model of the electric motorcycle was developed in Simulink to size the battery pack, the electric motor, as well as the right control strategy for the battery management system. This model was also the focus of different design…
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Powertrain Thermal System Development for small BEV

Honda R&D Co., Ltd.-Yoshikazu Ohnuma, Yosuke Yamagishi, Katsuya Minami
  • Technical Paper
  • 2020-01-1383
To be published on 2020-04-14 by SAE International in United States
The dynamic performance of battery electric vehicles (BEV) is affected by battery output power, which depends on state of charge (SOC) and the temperature of battery cells. The temperature of the batteries varies in particular with the environment, in which the user stores the vehicle, and the battery output power. It is therefore necessary to employ thermal management systems that can control the battery temperature within the optimal range under severely hot and cold conditions in BEVs. A highly sophisticated thermal management system and its operation strategy were developed to fulfill the above requirements. The powertrain components to be thermo-controlled were located into two coolant circuits having different temperature range. The compact and efficient front-end heat exchangers were designed to optimally balance the cooling performance of powertrain, cabin comfort, vehicle aerodynamics and the vehicle design. The battery pack was optimally thermo-controlled by precisely controlling two 3-way valves in all driving and environmental conditions. To reduce the temperature variation between battery cells, the coolant passage including cooling plates in the battery pack were designed so that…
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Comprehensive 3D thermal modeling of vehicle-ready battery module

SERES-Aditya Velivelli, Saeed Khaleghi Rahimian, Yifan Tang
  • Technical Paper
  • 2020-01-1385
To be published on 2020-04-14 by SAE International in United States
Thermal management of vehicle battery pack is crucial in determining the life / ageing of the battery pack, in establishing the range of the vehicle on a day to day basis and in determining the safety of the vehicle and occupants. An effective design of a thermal management system cannot be established solely through experimentation as it is time consuming and costly. Accurate computational models are required to aid in the design process. This study describes the development and validation of 3D computational model for simulating electrical and thermal characteristics of a vehicle-ready battery module. The modeling process starts with the full 3D CAD geometry of the module including the coolant channels and cold plate. As part of the study, an experimental test case was setup. This included a climate chamber for the initial soak of the module and to control ambient temperature. Coolant was pumped through channels underneath the cold plate atop which the cells sat in blocks. The cell bottom area conducted heat through a thermal interface material and through the cold plate.…
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Research on Heat Dissipation Performance of Battery Pack Based on Vertical Arrangement of Flat Plate Heat Pipes

Wuhan University of Technology-Xingmang Zheng, Gangfeng Tan, Meng Sun, Fangyu Zhou, ZhiQiang Liu
  • Technical Paper
  • 2020-01-0162
To be published on 2020-04-14 by SAE International in United States
Temperature is a direct factor affecting battery performance. If the temperature of the battery is too high or the temperature difference between cells is too large, it will accelerate the degradation of battery performance, reduce the battery life, and may cause safety problems such as thermal runaway in severe cases. Efficient thermal management of batteries is important to improve battery performance and safety. The flat plate heat pipe(FPHP) has high thermal conductivity, strong isothermal performance and light weight, it’s an ideal heat dissipating component for battery thermal management. In this study, the FPHP is used as the heat conduction component of the battery pack. Firstly, the position of the FPHP with minimum thermal resistance is obtained through experiments. Based on this, the heat dissipation effect of the FPHP on the battery pack is studied, and the purpose of reducing the maximum temperature of the pack and balancing the temperature difference between cells is achieved. In this study, a square LiFePO4 battery pack is taken as the research object. The one-dimensional heat model of the battery…
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Dynamic load identification for battery pack bolt based on machine learning

China University Of Mining & Technology-Deke Sheng
GAC Automotive Engineering Institute-Yuan Liu
  • Technical Paper
  • 2020-01-0865
To be published on 2020-04-14 by SAE International in United States
Batteries are exposed to dynamic load during vehicle driving. It is significant to clarify the load input of the battery system during vehicle driving for battery pack structural design and optimization. Currently, bolt connection is mostly applied for battery pack constraint to vehicle, as well as for module assembly inside the pack. However, accurate bolt load is always difficult to obtain, while directly force measurement is expensive and time consuming in engineering. In this paper, a precise data driven model based on Elman neural network is established to identify the dynamic bolt loads of the battery pack, using tested acceleration data near bolts. The dynamic bolt force data is measured at the same time with the acceleration data during vehicle running in different driving conditions, utilizing customized bolt force sensors. A data preprocessing method synthesizing Wavelet denoising method and machine learning algorithm is designed to improve model precision under dynamic condition. Parts of the pretreated acceleration and force data that obtained in various driving conditions are employed for model training, while the rest for model…
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Multi-scale Structural Analysis on Rubber Seal for Battery Pack

Cybernet System Co., Ltd.-Takahiro Sasaki, Takao Sato
Honda R&D Co., Ltd.-Katsuya Minami
  • Technical Paper
  • 2020-01-0498
To be published on 2020-04-14 by SAE International in United States
Rubber sealing for water-cooled battery packs plays a significant role to prevent water immersion into the inside of the pack. And the optimal design including the adjacent parts contributes to the weight reduction of battery packs by reducing the battery tray thickness and the quantity of bolts used in a whole battery pack. Generally, finite element analysis (FEA) is effective for the design optimization before proto-typing. But this application to the battery pack requires large scale analysis including the complicated contacts and large deformation of the rubber seal, and results in unpractically long computation time and frequent computation errors due to the finite element distortion. Multi-scale structural analysis and the process on rubber seals for battery packs has been developed to solve the above issues. This approach consists of 3 steps, which are single-unit, entire-scale and detailed structural analysis. The cross-section of rubber seal was simplified as rectangular shape by modifying the mechanical property of the seal so that the reaction force of the equivalent model agrees with the original one through Step 1. Using…
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Thermal Analysis of Electrical Contactor in Electric Vehicle Li-Ion Battery Packs

Romeo Power Technology-Gautam Pulugundla, Karlo Galvan, Prahit Dubey
  • Technical Paper
  • 2020-01-1345
To be published on 2020-04-14 by SAE International in United States
Modern high-power density automotive Li-Ion battery packs need robust and dedicated components to ensure efficient and safe operation of various constituent battery modules, and sub-systems. One such component is an Electrical Contactor (EC), which is an electronically controlled relay used for switching the high voltage power circuit of the DC battery pack. Specifically, the EC is operated by a control voltage that causes its internal current path to close during normal vehicle operations and open during certain pre-determined overload conditions. Therefore, ECs play an important role in providing a safe and reliable operation of an electric vehicle battery pack. An EC is typically connected to the power circuit of a battery pack through its load terminals via current carrying conductors like busbars and cables. To ensure a continuous operation of an EC under normal load conditions, the Joule heat generated by both the busbars and the internal EC circuity needs to be dissipated. Based on the power demand and voltage of the system, internal heat generation could result in overheating of the EC leading to…
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Battery cell modeling for energy and power estimations in a battery pack applied to a HEV

Juliana C M S Aranha, Felipe Lima Marques, Thiago Chiachio CPqD
  • Technical Paper
  • 2019-36-0243
Published 2020-01-13 by SAE International in United States
In this paper we present the concept of cell battery modeling and its importance to the battery management system of a HEV. A review of possible equivalent circuits to model the battery electric behavior is made and we present the proposed equivalent circuit to this application. This model takes into consideration the temperature, current and state of charge conditions in which the battery is being used, without adding equations to state-space model. Then, we discuss the laboratory tests that need to be performed to provide information for the models. A test procedure is presented in 6 different scenarios. Finally, the results of the application of this methodology for a NMC battery cell are showed. The maximum RMSE found between real and estimated voltage by the model was 1.0041e-4. A state of charge estimation using this model showed a 1.995e-6 mean squared error.
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Balancing Strategy for a Battery Applied in HEV Based on Bi-directional Flyback Converter and Outlier Detection

CPQD – Research and Development Center in Telecommunications-Felipe L. R. Marques, Juliana C. M. S. Aranha, Fernando F. Padela, Maria de Fátima N. C. Rosolem, Raul F. Beck
  • Technical Paper
  • 2019-36-0242
Published 2020-01-13 by SAE International in United States
Dissipative cell balancing generates heat during its operation. Current techniques do not guarantee optimal balance of battery pack energy, requiring a high-cost Battery Management System (BMS) solution and wasting energy in the form of heat. Mild Hybrid Electric Vehicles uses the combustion engine to recharge the battery. Therefore, this feature requires a BMS balancing system capable of optimizing battery capacity and still be energy efficient. In this way, a non-dissipative balancing system would be interesting, especially if an algorithm works with the former non-dissipative balancing method, which efficiently determines which cells are unbalanced. In this paper, a methodology is proposed to perform non-dissipative balance of lithium-ion cells. This method considers which cells inside a certain range are considered balanced and cells outside this range are considered unbalanced. The range is given by the median of the cells terminal voltage summed with a threshold defined by experimental tests. Due the non-dissipative method presented herein is conceived through Flyback topology, the cells above this range are discharged and their extra energy is employed to charge the lowest…
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Innovative Fluid Allowing a New and Efficient Battery Thermal Management

TOTAL Marketing Services-Jonathan RAISIN, Nicolas CHAMPAGNE
  • Technical Paper
  • 2019-01-2259
Published 2019-12-19 by SAE International in United States
With the increasing availability of fast charging stations across the globe, tighter and tighter constraints are placed on electric vehicles batteries. In order to handle the thermal stresses induced during fast charging, the improvement of the existing battery thermal management systems has become key. This article presents an innovative thermal management system for batteries. The system consists of circulating a newly developed highly advanced dielectric fluid in direct contact with the electrochemical cells of the battery pack. Experiments on our dedicated bench test and numerical simulations are reported here demonstrating the performance of this system with fluids, i.e. its ability to efficiently regulate the temperature of the battery cells even under fast charging conditions and low flow rates. Consequently, this thermal management strategy could be implemented within the next generation of battery electric vehicle (BEV) using conventional pumping systems and lead to an improved battery lifetime and therefore a lower total cost of BEV ownership.
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