Energy Saving and Environmental Measures in Railway Technologies: Example with Hybrid Electric Railway Vehicles

Abstract

The electric railway system is the highest class of energy efficient transportation means. This is due to two important points: (i) low running resistance (including low energy losses) and (ii) energy regeneration in braking.Regenerative braking of railway electric vehicles is effective when the other powering ones, in other words electrical load, exist near the regenerating train on the same electrified line. So, early in the morning and at midnight, or in the low-density district lines, regeneration cancellation phenomenon often occurs and the regenerative brake force cannot be operated in accordance with the recommended value. Newly appeared high-performance energy storage devices press the issues of energy storage and reuse technologies on ground and on vehicles. Hybrid energy source is one effective solution. In this paper, as an example, we show our trolley and on-board battery hybrid controlled tramcar, developed to reduce regeneration cancellation. With the trolley line collective power as well as charge and discharge power of the on-board lithium ion rechargeable battery, the hybrid energy providing and regenerating technology is achieved. The running test results show a maximum regenerative ratio of 44%, which is top class value in an electric railway system. 

Charge/discharge control of a train with on-board energy storage devices for energy minimization and consideration of catenary free operation

“…where I s , I c currents supplied from substations and EDLC current; f max maximum acceleration/deceleration force; r running resistance per unit weight of the train; P T electric power supplied to motor-inverters of the train; The objective function is sum of supplied energy from two substations given as (1). Equality constraints are given as (2)-(6).…”

“…Energy saving effect as well as preventing regenerative failure is expected. Some research projects on the application of the energy storage devices to railway systems have been reported in [1][2][3][4][5][6]. Most of them discussed reasonable circuit configuration and sizing of energy storage system, however, very few papers that deal with optimal charging/discharging control of the energy storage can be found.…”

Optimal Energy Management, Location and Size for Stationary Energy Storage System in a Metro Line Based on Genetic Algorithm

“…Current research activities have presented the application of batteries, flywheels, super-capacitors, and hybrid energy storages as energy storage devices [3][4][5][6][7][8]. Among the different storage systems available, super-capacitors seem to be the most appropriate for the application in a metro system for the advantages of rapid charging and discharging frequencies, a long cycle life, and high power density, which highly match the characteristics of metro system, such as short running time between stations, frequent accelerating and braking, booming power within a short time, etc.…”

Technical-Economical Evaluation of Chain Vertical Alignment in Underground Urban Subways: The Case of Qom Subway, Line A

“…1. The largest portion of energy consumption in railway operation is constituted by the energy consumed for running train cars that is about 70% of the total energy consumption (Ogasa 2008). Thus based on the Fig.…”