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Concerns about the environmental problems are growing worldwide, and the increase in the environmental load caused by motorization is one of major concerns. Electrification of the powertrain is essential for converting the conventional automobiles equipped with the internal combustion engine into more friendly automotive systems to the environment, and steady trends are observed in broader use of electric-powered drive train systems such as the hybrid vehicle and electric 4WD system, electric-powered chassis systems such as the electric power steering and electric brake, and electronic control of the automotive control systems such as the ISS and electric power generation control. The importance of electric power supply systems has been increasing as an automotive infrastructure supporting the electric powered systems and electronic control, and the demands' level for increasing the capacity, efficiency, and reliability of the electric power supply systems has been rising year by year. In order to meet these demands, the recent automotive electric power supply systems have become complicated due to redundancy and multiple-voltage capability provided in batteries and electric power supplies, employment of high-voltage batteries required for the electric-powered drive train systems, and employment of multiple converters controlling these multiple batteries and electric power supplies. Further, cooperation with the social infrastructure is necessary for systems receiving an electric power supply from the outside of the vehicle such as the plug-in hybrid vehicles. Considering these situations, domestic and international trends have been investigated focusing on technologies for integrating these electric power supply systems, and problems and solutions have been organized. Note that this investigation activity has been conducted from 2008 to 2009. |
