Development of a Supercapacitor Hybrid Powertrain Design with Pulse-Width Modulation and Series Configuration for Light Electric Vehicles

Supercapacitor hybrid systems for electric vehicle powertrain have been shown to improve fuel efficiency and battery lifetime. During acceleration and regenerative braking, the supercapacitor, which has a high-power density, handles transient power, reducing the power demand of the battery. The standard configuration places the supercapacitor in parallel with the battery. However, the practicality of such designs is low due to high complexity and cost. In this article, an alternative supercapacitor hybrid powertrain configuration was developed that uses a series configuration of two power sources with pulse-width modulation (PWM) for power control of the battery. Using the proposed design, power sharing and its control between two power sources are possible without bidirectional direct current (DC)-DC converters. The power system showed an average power reduction of the battery acceleration and allowed the supercapacitor to store energy recovered from regenerative braking directly.