01.10.07
Hitachi’s hybrid success
The world’s first hybrid trains have entered service in the UK and Japan. The trains are powered by Hitachi’s hybrid traction system developed with the aim of delivering substantial improvements in environmental performance by reducing energy consumption and the reduction of harmful emissions.
It’s no surprise that this breakthrough technology has been implemented first in the two countries renowned for delivering world firsts in railway technology for over 100 years, here made possible by Hitachi, the only rolling stock supplier to both the UK and Japan.
New Energy Train
In response to global trends of rising energy costs, uncertainty in future availability of resources and the threat of global warming, Hitachi and East Japan Railway Company (JR East) began the testing of the world’s first hybrid rail car in 2003. The New Energy Train was based on an EMU rail car with the power supplied to the traction converter from a diesel generator, and Hitachi’s lithium ion technology traction batteries, fundamental to the hybrid traction system success.
At the core of the hybrid traction system, the energy management system ensures the engine always performs at its most efficient operating zone. This reduces fuel consumption, harmful emissions and engine loading, delivering greater fuel economy, lower pollution and lower engine maintenance, when compared to a diesel rail car.
These results are achieved by meeting the traction power demand with a blend of battery and engine power, adjusting the battery contribution to maintain an efficient engine loading duty cycle.
The batteries are kept charged by regenerative braking, taking advantage of electric braking both at station stops and all other brake demand applications, something never before possible with diesel rail cars. This extra battery power available during acceleration means that for the same acceleration as a diesel powered car, a smaller engine, and cooler group can be used, reducing overall weight and cost.
Not only does the hybrid system address the environmental issues of energy use and emissions, but the availability of battery power allows the engine to be shutdown in stations reducing station noise and pollution. It is possible to accelerate out of the station on battery power alone, a huge improvement in local noise pollution. Finally to improve operational flexibility, it is possible to achieve engine off silent shunting at night using battery power.
Following three years of tests, Hitachi’s hybrid traction system demonstrated up to 20% savings in fuel consumption and a 50% cut in harmful emissions. Lower engine maintenance costs were also realised, and these figures resulted in the order of production vehicles, which entered commercial service this summer.
Hayabusa
In the UK, the railway’s green credentials are expected to clearly stand above those of competitor modes. The government is leading a drive to tackle global warming, and with 1/3 more unelectrified track in the UK, Hitachi believed the opportunity for hybrid technology was enough to start developments of a British hybrid train.
Hitachi took the opportunity of the UK’s numerous intercity unelectrified routes to trial an intercity version of the world’s first commuter hybrid already so successful in Japan. In addition to demonstrating the safe operation of the system on UK infrastructure, hybrid performance benefits demonstrated on intercity routes would also make the case for hybrid rolling stock as the future for both intercity and commuter routes.
Working with partners Porterbrook, Network Rail and Brush Traction, the Hitachi hybrid traction system was installed into a Porterbrook Class 43 HST locomotive and a Mark III TGS coach, with the integration and modification work carried out by Brush Traction for eventual commercial service as part of Network Rail’s New Measurement Train.
The modification work included the replacement of the power car’s original DC traction motors with Hitachi AC driver traction motors, and the installation of the Hitachi traction inverter, and traction batteries, into the TGS vehicle. The TGS vehicle was required due to weight/space restrictions in the original power car. Finally the reworked vehicles were painted in Network Rail yellow. The work was completed in April 2007.
In May 2007 the world’s first hybrid high speed train was unveiled at Quorn Station on the Great Central Railway. The four car train, including a conventional power car at the opposite end to the hybrid, was named Hayabusa, Japanese for falcon. The initial demonstration run for all the invited guests drew gasps as the first HST to move under eerily quiet electric battery power pulled out of the station.
This marked the first of three stages of testing for Hayabusa. It quickly reached 60 mph, the maximum running speed for the Great Central Railway, in the first days of the test, and continued to carry out braking and EMC testing before transferring onto the Midland Mainline for the first tests on Network Rail Infrastructure.
Again 100mph was achieved early on, and testing of the hybrid system successfully proved the regenerative braking, blended pneumatic and electric brake, and battery assisted acceleration. Even the drivers commented on the smoothness of the acceleration and braking performance compared to a conventional HST. Operation with one hybrid power car and with both the hybrid power car and conventional power car together was carried out, proving the required operation for service on the NMT.
The train was increased from four to five to seven vehicles through the summer, before Hayabusa joined the NMT. From September, Hayabusa begins operation as part of the NMT where running in full operation together with a conventional power car, it will be possible to measure the difference in fuel consumption between the hybrid and conventional power cars.
The future
While Hayabusa’s successful testing continues, Hitachi continues to press forward with developments in Japan to further improve environmental performance. The New Energy Test Train has had the diesel power plant replaced by a fuel cell power module running off bottled hydrogen. With testing of this fuel cell, battery assisted hybrid train already underway, Hitachi believe that they have taken the first crucial steps towards delivering zero-carbon go-anywhere trains to the global rolling stock market.
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