Alternative Fuel Safety
Many manufacturers are heavily investing for near future production and marketing of alternative fuel vehicles. These include electric vehicles, hybrids, fuel cells, hydrogen compressed and liquid natural gas, liquid propane, and hydrogen. As these vehicles are deployed in the fleet, their safety during refueling, recharging, and in crashes, become issues of paramount concern. Ensuring that alternative fuel vehicles attain a level of safety comparable to that of other vehicles requires extensive research, due to the many advanced and unique technologies that have previously not been tested in the transportation environment. A failure to adequately address safety concerns in the earliest stages of development could affect the future development of these promising technologies.
This project involved three series of experiments to assess test procedures for fuel system integrity after a crash as specified by the Society of Automotive Engineers. The first series compared hydrogen fuel tank vulnerability to impacts at high and low states of fill. The second series assessed the use of helium as a non-flammable surrogate fill gas for crash testing. The third series retrofitted Honda Civics fueled by compressed natural gas with hydrogen containers and subjected them to crashes to obtain data and to develop test procedures to remotely defuel high pressure systems after testing.
For alternative fuel vehicles such as those using electric battery power or compressed gas fuel cells, the issue of how to protect occupants and first responders from electric shock hazards following a crash is a serious issue. This report presents the results of an assessment of protective barriers, possible failure modes associated with contact with high-voltage sources, and test methods for verifying that the protective barriers provide adequate levels of protection from hazardous electrical currents.
- Determination of Battery Stability with Advanced Diagnostics (DOT HS 812 249)
This project was the first effort to develop enhanced state-of-stability assessment
tools for real-time safety determination of lithium-ion battery systems. The focus is to develop efficient and cost-effective technology into next-generation automotive battery management systems. Based on 5 months of a 24-month project, one aspect of the model used a new metric based on rapid impedance spectrum acquisition during performance and abuse testing for module configurations, comparing experiment data to identify a solution. Mitigating or avoiding thermal safety conditions is key to acceptance of Li-ion batteries in vehicles, and earliest detection of a heat safety problem in is essential. Laboratory technology currently exists that allows measurement of impedance that provide this favorable insight; however, it is not practical in its current form for vehicle integration.
- Status Update on NHTSA's Lithium-ion based Rechargeable Energy Storage System Safety Research Programs
- Post-Crash Hydrogen Leakage Limits and Fire Safety Research, DOT HS 811 816
- Cumulative Fuel System Life Cycle and Durability Testing of Hydrogen Containers DOT HS 811 832
- Hydrogen Fuel Cell Vehicle Fuel System Integrity Research - Electrical Isolation Test Procedure Development and Verification
- Analysis of Published Hydrogen Vehicle Safety Research
- Hydrogen Program
- Localized Fire Protection Assessment for Compressed Hydrogen Containers - NVS-321
- Failure Modes and Effects Analysis for Hydrogen Fuel Cell Vehicles - Subtask 1
- Compressed Hydrogen Research and Testing In Accordance with FMVSS 304