Range extension of electric vehicles by two battery HEECS chopper based power train

Abstract

This paper first shows efficiency maps of electric power train based on a two battery High Efficiency Energy Conversion System (HEECS) chopper. HEECS is based on the principle of partial power conversion, and the overall efficiency of HEECS chopper is high and over 99% [1]. The efficiency of this power train was measured in states of constant speed and constant torque by the motor test bench. Second based on these data the several driving test was simulated and the range extension is investigated. The energy consumption is estimated in JC08 mode and 10–15 mode which are Japanese standard driving cycles, and compared with non-chopper power train, the reduction of the consumed energy is estimated 5.7% in JC08 mode and 6.7% in 10–15 mode. Finally experiments were carried out, and 6.6% energy saving is confirmed in 10–15 mode cycle test. This means that the power train by two battery HEECS is more suitable for urban driving cycle pattern than for high speed driving cycle.