Hybrid Electric/Battery-driven Railcar System

JR East Completes Testing Hybrid Electric/Battery-driven Railcar System, Proving Its Effectiveness ''The Smart Denchi-kun Train''

JR East announced on November 6 that it planned to begin operating its first hybrid electric/battery-driven train. This announcement came after the company completed tests confirming the effectiveness of a battery-driven railcar system, making it possible to use the system for two-car train operations on the Karasuyama Line in Greater Tokyo. The test rolling stock is nicknamed “NE Train Smart Denchi-kun,” and the first train for regular operations is scheduled to begin running around the spring of 2014, as a new way to reduce environmental load on non-electrified track sections. In the future, this new type of train will replace all diesel railcars on the Karasuyama Line. (Presently, the company runs four two-car diesel trains on the line.)

Operations to begin on Karasuyama Line in spring 2014

On non-electrified track, the battery-driven railcar system draws power from large-capacity batteries installed in the train. On electrified track, the system uses power from the overhead catenary line to run like a regular electric train, while charging the batteries at the same time. The company expects that the system will offer environmental benefits, by reducing carbon dioxide emissions and other exhaust gases from the diesel engine, and by reducing noise as well.

On the Karasuyama Line, through trains from Utsunomiya heading away from Tokyo will charge their batteries on the electrified section between Utsunomiya (on the Tohoku Line) and Hoshakuji, a distance of 11.7 km. Then they will use the power stored in the batteries to run on the non-electrified section between Hoshakuji on that line and Karasuyama (20.4 km). The batteries will also be recharged using power from regenerative braking. Charging equipment manufactured specifically for the system will be installed at Karasuyama Station for trains heading toward Tokyo, to charge their batteries with electricity via the pantographs when the train is stopped there, providing more energy required for train operations.

The system will be installed on the Karasuyama Line first because the batteries are able to power the train for about 20 kilometers, making them suitable for the length of the line’s non-electrified section. CO2 emissions are expected to be about 60% less than the diesel trains currently operating on the line. Also important is the fact that the new system will permit through services onto the DC electrified line segment.

The car type is EV-301. EV stands for Energy storage Vehicle, since storage batteries will also power the electric train. The design specifications include a weight of 40 tons per railcar, a maximum speed of 100 km/h, and the use of 600V, 95kWh lithium-ion batteries in each of the two railcars. Plans call for a passenger capacity of 265 for the two cars, with longitudinal seating. All interior lighting will be from light-emitting diodes (LED), to further reduce electrical consumption.

The charging equipment manufactured for the system will draw electricity from an electric power company’s wires, and a transformer will step down and rectify the voltage from 6,600V AC to 1,500V DC. That power will then be supplied to the railcars via an overhead rigid conductor, then stepped down again inside the train to 600V, and finally transmitted to the batteries and main circuit. The cost for the developments, including one trainset, the charging equipment, and raising the height of platforms on the Karasuyama Line, is about 1.8 billion yen.

The company began developing the battery-powered hybrid railcar system in fiscal 2008, mainly in order to reduce environmental load. After manufacturing the test train “NE Train Smart Denchi-kun” in fiscal 2009, it conducted numerous test runs in station yards and on electrified track (part of the Tohoku Line and the Nikko Line). Then at the end of fiscal 2010 the test runs were done using the charging equipment at the Utsunomiya Operations Yard as well. During tests in February and March 2012, the company verified the system’s effectiveness on track primarily between Koganei and Karasuyama.

This article appeared in the Kotsu Shimbun newspaper on Friday, November 9, 2012. We thank the publisher, Kotsu Shimbun-sha, for granting permission to present the article translated under the auspices of JORSA.