We performed immersion tests of battery packs for electric vehicles using tap water and salt water to confirm the safety when an electric vehicle was submerged such as in floods. The discharge current during the immersion tests in saltwater immersion exceeded that for tap water due to the difference in electric conductivity. However, there was no ignition or explosion. Therefore, the battery should remain safe even if water flows into the battery pack.

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This study sought to clarify the driver's effective response rate when using a driver-support system for Advanced Safety Vehicles (ASVs). The Night-Vision Enhancement System (NVES) is an ASV technology for providing visual information to prevent hitting pedestrians due to poor visibility at night. In this study, a driver's response to the NVES was examined on a test course using an instrumented vehicle. The experiment clarified the driver's effective response rate when using NVES.

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To evaluate the validity of post-crash concentration tests for enclosed spaces of hydrogen-fueled vehicles suggested by HFCV-gtr, we investigated the influence of the collision barrier and wind on the hydrogen concentration in enclosed spaces using a vehicle after a side-crash test, in comparison to an alternative test using helium gas. The test results indicated that the hydrogen concentration of the enclosed space varied depending on contact with a moving barrier and light wind (wind velocity 0.1m/s). Moreover, the He / H2 concentration ratio of the enclosed space was less than 0.75, depending on the leakage location or the nozzle diameter. Thus, many problems in conducting post-crash concentration tests remain.

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We conducted hydraulic sequential tests of the new domestic standard ''KHK S 0128'' for existing VH3 tanks. The temperature and pressure control regulations of the procedure are not detailed in the accelerated stress test, one of the sequential tests. We therefore investigated the influence of the temperature and pressure control procedure and found that the control procedure affects the fatigue life of the VH3 tank. However, the procedure can be evaluated properly the safety of the VH3 tank.

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To examine the safety of rescuers when hydrogen leaks from an FCV vehicle, we investigated the relationship between the minimum audible threshold of hydrogen leakage sound and the flow rate of hydrogen, and performed frequency analysis of the hydrogen leakage sound. Tests were performed with hydrogen leaks from a simulated FCV vehicle with background noise in the test area of about 40 dB. The test results indicated that if hydrogen leakage can be heard, the rescuer should listen to the sounds around the vehicle before approaching it. If hydrogen leakage cannot be heard, the rescuer can approach the vehicle safely.

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We conducted the fast fueling test to hydrogen storage tanks for FCV to validate safety of the fallback fueling method switching APRR(average pressure ramp rate) at various SOC(State of Charge) . As a result, it was confirmed that final gas temperature in tank decreased according to switching SOC higher, and never exceeded 85oC when fallback fueling is done. This showed that the fallback fueling was able to fuel safely even if fueling gas temperature rose.

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[in Japanese]

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The speciation of organic carbon (OC) and elemental carbon (EC) are measured on source and ambient quartz-fiber filter samples by several thermal-optical carbon analysis methods. The split between OC and EC is defined based on combinations of combustion temperatures, residence time at each temperature, the composition of the atmosphere, helium or helium plus oxygen, surrounding the sample, and light reflected from the filter. In the last several years, the world has experienced a supply shortage and large cost increase for helium. This investigation demonstrated that using nitrogen instead of helium as the carrier gas provided equivalent measures of total carbon (TC), OC, and EC for authentic samples. The determination accuracies were verified by analyzing sucrose solutions for calibration standards, spark graphite (GFG 1000) for EC samples, the National Institute of Standards and Technology (NIST) SRM 1648a for urban dust, SRM 1650a/2975for diesel exhaust, the National Institute for Environmental Studies (NIES) CRM No. 8 for automotive exhaust in tunnels, and CRM No. 28 for urban aerosol in Beijing. Using nitrogen instead of helium yielded equivalent TCs for authentic samples within the electric microbalance errors that would be introduced by electrical charging of dust samples. However, the carbon fractions (i.e., OC/EC splits, or OC1, OC2…) were not well reproduced for several samples for this investigation. More data sets need to be analyzed to evaluate the use of the source and ambient samples.

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[in Japanese]

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This article describes International Standards prepared by a technical committe ISO/TC22, Road vehicles, a subcommittee SC21, Electrically propelled road vehicles. Firstly, it briefs the structure of ISO and ISO/TC22, and secondly it describes ISO/TC22/SC21; its structure, working groups (WG), and International Standards and other ISO documents both published and in progress. Finally, it focuses on the International Standards which JARI have taken the lead in preparation of.

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[in Japanese]

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[in Japanese]

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