Regenerative braking of railway electric vehicles is effective when other powering vehicles, in other words electrical load, exist near the regenerating train on the same electrified line. So, at early mornings and late nights, or in the low-density district lines, regeneration cancellation phenomenon often occurs and the regenerative brake force cannot be operated in accordance with the commanded value. The new high-performance energy storage devices tackle the issues of energy storage and reuse technologies for on-ground and on-vehicle situations. A hybrid energy source is one effective solution. In this paper, the effective use of regenerating braking and the expected electricity storage technology in future for further energy conservation in the electric railway field will be outlined, with actual examples. 

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. 

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