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Accurate estimation of the State of Charge (SOC), maximum capacity (Qmax) and internal resistance (R0) are essential for efficient battery monitoring, which is an important part of the battery management system. SOC provides information regarding the instantaneous status of the battery system, while Qmax is a key indicator of the long-term State of Health (SOH) of the cell, which represents the abilities of a battery to store energy and retain charge over extended periods. In addition, the internal resistance is also required to predict the peak available power. Traditional methods use complex models and look-up tables that have high computation requirements and are thus unsuitable for online applications. In this paper, we propose a simple method for simultaneous SOC, Qmax and internal resistance estimation based on a second-order equivalent circuit model (ECM).

A feature of Baja SAE, and other off-road racing series, is a dynamic traction event. Usually some sort of pull-test device is towed in this event, and design of this device has a controlling influence on the performance capability of each vehicle in the field. Pull-test devices are usually designed to be progressive so that starting is easy, but the pulled load gets higher the further the tow proceeds. Pull-test devices must also be mechanically designed to suit the efficient operation of the traction event (hitching and resetting). This paper develops the operating and design theory of a new pull-test device, the log pull.

This paper presents theoretical and experimental analyses used to evaluate the behavior of a capacitor-based hybrid source while supplying a pulsed current load. A PEM fuel cell and a variety of battery types were tested in the laboratory for their capability to supply a pulsed load. The capacitors used during testing were found to be effective in reducing the fuel cell/battery current. Experimental test results show that using low-ESR capacitors can reduce voltage deviations. Test results also show that a capacitor-based hybrid is a promising power source for supplying a pulsed current load.

Values for Shear stress, Specific power and Energy for gray and ductile cast irons have been determined using two orthogonal machining setups. Procedures for determining machinability by tool life testing are reviewed, and compared to orthogonal machining methods. A new method which will produce very precise values for shear stress, specific power and energy is described.

AC impedance measurements have been taken for five different double-layer capacitors (DLCs) operating at different DC bias levels. Using these measurements, circuit parameters for different DLC equivalent circuits have been determined. The effect of DC bias on the circuit parameters has been investigated. Variations in manufacturing were also examined. Equivalent circuit parameters were calculated for a small group of 50F DLCs and then compared. The equivalent circuit parameters varied about 10% over the sample set.

This study analyzes the performance of the Energy Recovery System (ERS) of a Formula One car (F1) based on the qualification performance of 19 drivers for the first calendar race of the 2019 FIA Formula One World Championship®. In this study, the race circuit analysed was split into different sectors to examine the energy transfer between the Motor Generator Unit-Kinetic (MGU-K) and the Energy Storage (ES) systems. Positive Kinetic Energy (PKE) concept was used for estimating the energy deployment potential of the ERS along with numerical simulations for estimating the energy recovering potential. This investigation highlights the strategies used by different drivers and the effect of driver to driver variation on their ERS performance during qualification. The methodology demonstrated in this study is able to identify the correlation between the unique driving style of individual drivers and the ERS strategies used by the teams for maximizing the performance of their car.

The structure of a Baja SAE car is designed to be lightweight and ensure driver protection similar to the Formula SAE series; however the loading conditions that a Baja SAE car sees are very different. The terrain that the car drives over is the key difference. Baja cars drive on very dynamic terrain that often cannot be classified as a road. This terrain leads to load cases that put very high dynamic stresses on the frame. These may include symmetric or asymmetric suspension loading, impact loading, as well as drivetrain loading. The testing for this work was conducted on the endurance track for the SAE Mini Baja East 2006 race. The two specific load cases presented in this work were conducted on controlled sections of the track. Also, random data was taken on other areas of the track. This track is considered to have a sampling of obstacles and terrain that would be a good representative of what SAE Baja vehicles typically encounter.

A comprehensive multi-physics theoretical model of the solenoid valve used in an automobile transmission is constructed using the finite element method. The multi-physics model includes the coupled effects of electromagnetic, thermodynamics and solid mechanics. The resulting finite element model of the solenoid valve provides useful information on the temperature distribution, mechanical and thermal deformations, and stresses. The model results predict that the solenoid valve is susceptible to a coupled electrical-thermo-mechanical failure mechanism. The coil can generate heat which can cause compressive stress and high temperatures that in turn could fail the insulation between the coil wires. The model facilitates the characterization of the solenoid valve performance, life and reliability and can be used as a predictive tool in future solenoid design.

Analysis of thermal behavior of Lithium ion battery is one of crucial issues to ensure a safe and durable operation. Temperature is the physical quantity that is widely used for analysis, but limited for accurate investigations of behavior of heat generation of battery because of sensitivities affected by heat transfer in experiments. Calorimeter available commercially is widely used to measure the heat generation of battery, but does not follow required dynamics because of a relatively large thermal time constant given by cavity and a limited heat transfer capability. In this paper, we proposed a highly dynamic calorimeter that was constructed using two thermoelectric devices (TEMs). For the design of the calorimeter and its calibration, a printed circuit board (PCB) with the same size as the battery was used as a dummy load to generate controlled heat.

Despite the widespread adoption of lithium-ion batteries in various applications such as energy storage, concerns related to thermal management have been persisting, primarily due to the heat generated during their operation and the associated adverse effects on its efficiency, safety, and lifetime. Hence, the thermal characterization of lithium-ion batteries is essential for optimizing the layout of the battery cells for a pack design and the corresponding thermal management system. This study focuses on an experimental investigation of heat generation of Li-ion batteries under different operating conditions, including charge-discharge rates, ambient temperatures, states of charge, and compressive pressure. The experiments were conducted using a custom-designed multifunctional calorimeter, enabling precise measurement of the heat generation rate of the battery and the entropy coefficient. The measured results have shown a good match with the calculated heat generation rate.