Novel Power Conversion System Contributing to Green Public Transport

Abstract

Electrified public transport is winning increasing recognition for its less environment and energy impact. The conventional power conversion systems for on-board low voltage applications of public electric vehicles are suffered from relatively low energy efficiency and short lifetime. A cost-effective high-efficient power conversion system for Trolleybuses, Trams, Metros and Light Rails is invented. With innovative concepts from device selection, circuit design to system optimization, the proposed conversion system exhibits 20% energy savings and 50% volume and weight reductions. 400% lifetime extension is achieved by adopting a patent-pending technology that reduces the capacitor energy storage requirement. Therefore, the short life cycle aluminum electrolytic capacitors are replaced by long lifetime power film capacitors without increasing the cost and volume. Two 2 kW, 1.5 kV to 48 V dc-dc converters have been built and evaluated. The experimental results are in well agreement with theoretical predictions. This report reveals that the urban rail market enjoys fast growing in the next five years. During 2012-2016, the overall addressable market volume for the proposed conversion system is $2.5 billion in the world. Specifically, the market sizes in China and the whole Asia Pacific Region are $555 million and $1.2 billion, respectively. The strengths, weakness, opportunities, threats (SWOT) and market viability of the proposed conversion system have been analyzed to address its business potentials.