Abstract
Diesel engines are widely used for medium and large sized vehicles because of their good performances such as high power, high efficiency and low fuel consumption, however, emission of black smoke and nitrogen oxide gas is still to be improved. One of the possible solutions for the improvement is the diesel-electric hybrid system called HIMR systems, the world first example of realizing the diesel-electric hybrid low emission city buses. The HIMR is the parallel hybrid system consisting of an induction motor incorporated in the diesel engine, an micro-processor controlled inverter to control the induction motor, and batteries as energy reservoir. The system has various functions to keep low emission, low fuel consumption, good drivability and reliability. And main control is performed by the micro-processor in the inverter. Low-emission city route buses with the HIMR system have been extensively monitored since December 1991. Various tests were carried out which show favorable results in achieving low emission, including a reduction of such pollutants as NOx and black smoke and improvements in fuel consumption and brake lining wear. This paper gives features, functions and the results of monitor tests of the HIMR system.