The SAE G-27 committee was tasked by ICAO to develop a performance-based packaging standard for lithium batteries transported as cargo on aircraft. The standard details test criteria to qualify packages of lithium batteries & cells for transportation as cargo on-board passenger aircraft. Lithium batteries and cells have been prohibited from shipment as cargo on passenger aircraft since 2016. This paper summarizes the results of the tests conducted by Transport Canada and National Research Council Canada to support the development of this standard with evidence-based recommendations. It includes a description of the test specimens, the test set up, instrumentation used, and test procedures following the standard as drafted to date. The study considered several lithium-ion battery and cell chemistries that were tested under various proposed testing scenarios in the draft standard. The aim was to assess the feasibility of proposed tests, and to determine whether the tests are able to accurately capture hazards which may arise from a catastrophic battery or a cell failure within the package. Laboratory results were also simulated with Computational Fluid Dynamics…

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.

The discussion in the braking industry that has been ongoing for over a decade now on how to specify brake systems for regenerative-brake intensive vehicle applications has intensified considerably in the past few years as the automotive industry ponders a future where electric vehicles become predominant. Major automotive manufactures have announced plans to create dedicated electric-only vehicle architectures, from which to offer a full range of electric vehicle configurations. The time to really figure out the translation of Voice of the Electric Vehicle Customer to technical requirements and brake system content is approaching very rapidly. One of the major design decisions in the brake system is the sizing of foundation brake components for thermal performance. There is no question that regenerative brakes can significantly reduce the demand on the friction brakes in normal usage, sometimes by a full order of magnitude or more. Brakes no longer need to be sized for everyday use, rather, the sizing is driven by “limit cases” such as failure of the regen system, a full state of charge in the…

It is proposed a study to evaluate PHP (pulsating heat pipes) device application in battery thermal management systems for HEV (hybrid-electric vehicle) and EV (electric vehicle). Firstly, it is necessary to understanding Li-ion (lithium ion) batteries for HEV/EV, the electrical energy supply state-of-the-art. The analyzed aspects were battery framework and configuration; working principles and mechanisms; and market penetration and potential. Secondly, the adverse effects of temperature over such batteries were discussed. After understanding the case study, a battery modeling survey was performed in order to later evaluate BTMSs (battery thermal management systems). Well comprehended case study and battery modeling, then, it was possible to examine current automotive battery cooling and heating solutions. Finally, PHP was evaluated as a possible BTMS regarding technical and commercial aspects, explaining what would be the requisites in order to attend automobile heat dissipation demands and the challenges for embedding it.

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…

Model based development is an approach pursued to obtain an advanced insight into powertrain & vehicle development. This approach enables the ability to trace errors early on, thereby reducing the dependence on field testing and saving cost & time involved in the development process. The purpose of this study is to develop a system level battery electric vehicle model using GT-Suite as modeling platform, for Light Heavy Duty applications. The outcome of this study is electric range estimation, performance analysis, component sizing and optimization for inverter-motor and battery components. The model has been developed using a map-based approach. Hence, the simulation time is faster than real-time, requires less input data and can be used for preliminary range & performance estimation. The model fidelity has been validated against performance, acceleration, deceleration and coast-down data obtained from field testing. Apart from field data, standard EPA drive cycles and customer usage based drive cycles have been used as target to the model. Energy efficiency (Wh/mile) and MPGe calculations have been performed as part of model validation. The applications…

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.

Honda has developed an electric powertrain for the new model plug-in hybrid vehicle. In order to realize the EV performance, it was necessary to increase the power output of the high-voltage DC-DC converter to boost the battery voltage (referred to as a “Voltage Control Unit (VCU)” below). An interleaved circuit using the newly developed coupled inductor was employed to reduce the magnetic flux leakage to the exterior as the method of increasing the power density of the VCU. The application of the inductor has increased the continuous power density of the VCU approximately 2.8-fold in comparison with the conventional unit employed in previous Honda hybrids.

Fuel cell vehicle and battery electric vehicle are two environmentally benign vehicle technology types possibly meeting the zero-emission regulations in the future. The premise is they can achieve parity with conventional vehicle both environmentally and economically. Besides, it is necessary to distinguish which technology is more suitable in China's current and future context. This paper compares their cost-effectiveness for reducing greenhouse gas emissions, examining the life-cycle greenhouse gas emissions of conventional gasoline vehicle, battery electric vehicle and fuel cell vehicle in China's energy context under three different scenarios. The results indicate that under the 500km drive range, fuel cell vehicles are less competitive than battery electric vehicles currently. Fuel cell vehicles generate much more greenhouse gas emissions than battery vehicles and conventional gasoline vehicles. While with the optimization of energy context, fuel cell vehicles can gain competitiveness with battery electric vehicles in terms of greenhouse gas emissions, and with mass production as well as fuel cell system cost reduction, fuel cell vehicles can realize a better cost-effectiveness. Based on this analysis, it is recommended that…