Browsing College of Engineering and Mines (CEM) by Subject "Management"
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Modeling and exploring battery management strategies for use of LiCoO₂ lithium polymer cells in cold climatesAs the use of batteries to power vehicles becomes more common, a robust battery management system becomes necessary to monitor and maintain the batteries. Cold weather places a further burden on this system especially in small electric vehicles such as snowmobiles where it is desirable to use every bit of available energy from the battery cells. The problem with current battery management technology is that use of batteries in cold temperatures is often not addressed. The objective of this research was to develop an appropriate model of a lithium polymer cell with a cathode comprised of LiCoO₂ and develop an optimized charge/discharge method taking into account the effects of extreme cold weather and cell state of charge imbalance. A cell model was adapted and tuned that accurately captures the dynamics of a lithium polymer cell when discharged at temperatures below freezing. The model results were verified against cells discharged in an environmental chamber, which allowed accurate control of ambient temperature. Multiple scenarios were explored, looking at the effects of ambient temperature, cell initial temperature, internal heating, battery pack insulation, and how rapidly the cells were discharged. The results of the optimized battery management strategies showed improvements in the energy delivery capability of lithium polymer battery packs for small vehicles operating in extreme cold environments. In addition, this research extended the LiCoO₂ model down to -20 °C using validated data, showed that perceived cell capacity loss at low temperatures is primarily due to increased internal resistance, demonstrated that measured cell terminal voltage can rise under load at low temperatures, and showed that increasing the capacity of a battery pack has a better than linear gain in usable energy versus increased battery capacity. I.e., doubling battery pack capacity will more than double the useable range of the vehicle.
PROMOTING CSET OUTREACH ACTIVITIES THROUGH SAFETY DATA MANAGEMENT AND ANALYSIS IN RITI COMMUNITIESTraffic crashes are one of the leading causes of death among all people in the United States, but the rates among American Indian and Alaska Native (AIAN) populations are significantly higher than other groups. In fact, rural areas in general are disadvantaged from a traffic safety perspective due to the lack of funding and challenges in safety improvement decisions. This may contribute to the much higher fatality rate on rural roadways than on urban roadways. Additionally, there is a known issue of underreporting of fatal crashes of tribal members. Thus, an increased focus on rural, isolated, tribal, and indigenous (RITI) community traffic safety is necessary in order to progress towards zero fatalities. The need for quality data is recognized, and even included in many tribal transportation plans, but implementation and collection of the data varies. Quality data enables better safety analysis and enables greater support for traffic safety improvements. An easy-to-use and multisource database would enable tribes throughout the state and other rural communities to more readily manage data and apply for improvement funding. In order to reach this point, it is necessary to have agreements with tribes on crash data collection and usage, and understand local customs, needs, and current practices. This research aimed to form trusting and lasting relationships with tribal leaders in Washington State in order to facilitate crash database management and traffic safety analysis in their communities. The outreach activities included meetings with local tribal leaders, interviews, and attendance and presentations at tribal conferences. Ultimately a formal research agreement was signed with one tribe in Washington State granting access to the fatal and serious injury crash data they had collected.
A review of oil spill history and management on the North Slope of AlaskaAlaska has an abundance of natural resources including oil, natural gas and coal. It is critical to minimize the occurrence of oil spills to ensure protection of Alaska's people and the environment. The objective of this project is twofold. One is to provide a quantification of the number of spills on the North Slope (NS) as well as the number of contaminated sites that are generated, describe the regulatory requirements for the Arctic zone, and discuss cleanup methods. Second is to describe the ADEC regulations as they pertain to terrestrial oil spills. The region of study begins north of Alyeska's Pump Station 4 at the Dalton Highway milepost 270, TAPS 144, north to the Beaufort Sea, encompassing all oil related operations. This review excludes spills at villages (not related to oil field operations), and releases to the atmosphere (e.g., halon, propane). Additionally, spills at formally used defense sites (FUDS) and long range radar sites are also excluded from this study. Spills that result in long term monitoring and cleanup are managed as contaminated sites. The data reveals that the majority of contaminated sites have been cleaned up with no institutional controls in place. The number of spills on the North Slope is consistent with activity. The time during the peak oil is when there are a higher number of spills. Over time, as the oil production and activity decline, so do the number of spills with a few exceptions. The decline in oil production has limited activity and growth on the NS.