Research on improving the reliability and reducing the weight of battery packs for railway vehicles

Abstract

In the railway industry, there is ongoing research on incorporating large-capacity energy storage system (ESS) into railway vehicles to reduce carbon emissions and enhance energy efficiency. Lithium-ion batteries are widely used in ESSs due to their high energy density. However, their high chemical reactivity can lead to a higher risk of malfunction. This compromises the reliability of railway vehicles using a high-capacity ESS as a propulsion power source. This study aims to improve the reliability of the battery packs used in railway vehicles by introducing a novel circuit configuration that integrates a bypass circuit into the traditional redundant circuit configuration used in lithium batteries. In conventional ESS systems, an additional battery pack needs to be equipped to sustain normal operation in the case of a battery malfunction event. However, this leads to a substantial increase in the volume and weight of the ESS. The circuit configuration proposed in this paper guarantees the normal operation of the ESS in the case of a battery failure using a few additional circuit components. The feasibility of the proposed circuit configuration and its operation are examined using railway vehicle battery pack specifications.