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An IGBT model for use in circuit simulations (called the “HiSIM-IGBT model” below) has been developed that can be applied to the design of electrical characteristics occurring in accordance with the complex control methods adopted by the power converters of electric and hybrid vehicles. Since the HiSIM-IGBT model expresses carrier behavior inside the IGBT with physical formulas, electrical characteristics can be simulated with high accuracy, enabling very precise and rapid design of electrical characteristics using IGBTs.

A quite interesting self-excited oscillation phenomenon in engine speed, which may not be explained with the classical theory of mechanical hunting, is studied experimentally. The effects of the various engine operating variables on the phenomenon are examined using a four cycle single cylinder gasoline engine with an inertia governor. It was found that the phenomenon occurs when engines are operated at a lean air fuel ratio under light load conditions, and that the hunting phenomenon is ascrlbable to the temporary shift in air fuel ratio from the steady state value. This shift in air fuel ratio occurs due to the fuel flow delay into the cylinder caused by the fact that the fuel flow into the cylinder cannot follow the movement of the throttle valve.

This paper describes a new stratified-charge combustion system called the Mitsubishi Combustion Process (MCP), accomplished by controlling the air swirl and improving the injection nozzle in regulating fuel injection, which reduces poisons from exhaust emissions of small engines. Experiments proved that the MCP engine reduces the emission level; for example, with gasoline the concentrations of HC, CO, and NO are 80 ppm, 0.20%, and 600 ppm, respectively, at the rated horsepower. The engine shows excellent performance in multifuel and starting characteristics. The improvement of spray formation that has an important effect on exhaust emissions and other engine performance is also described.