The electric power of most electric two-wheelers on the market ranges between 2 and 12 kW. For this power range, the traction voltage level is mostly between 48V and 96V. There appears to be no strong correlation between electric power and traction voltage, suggesting that the current voltage choice is rather arbitrary.
This paper briefly describes the e-motor model used in this study and introduces variations of four design parameters: DC voltage, maximum phase current, e-motor active length, and the number of turns in the e-motor winding.
The consequences of these variations on peak performance, continuous performance, and efficiency maps are presented. Specific cases of parameter combinations are also studied. Two e-motors designed for 48V and 96V systems will be compared, showing that size, cost, and performance (power and losses) are equivalent. Additionally, the paper discusses how increasing the maximum phase current rating of the inverter can improve e-motor power in a 48V system. Downsizing the e-motor by using more phase current is also explored, with its impact on continuous performance and efficiency.
The paper concludes that for most electric two-wheelers below 12 kW, a traction voltage higher than 48V does not offer significant advantages.