Wednesday, June 3, 2009
JR 500 World's Fastest Electric Vehicle
In the second of our series of articles where we look at the world's biggest electric vehicles in an effort to dispel the myth that EVs have to be low powered and slow vehicles we'll take a look at the fastest rail based electric vehicles, high speed trains.
All high speed rail systems are electrically powered and there are quite a few that run scheduled services at 300 km/h these days. The Japanese Shinkansen Bullet Trains have been operating since the 1950s and the first of the Bullet trains to routinely go into service at 300 km/h was the JR 500.
Constructed by Hitachi and Kawasaki between 1995 -98, the JR-500 features a nose like a supersonic jet, has active suspension and is designed for a maximum speed or 320 km/h. Run in either 8 or 16 car configuration, the JR-500 can carry up to 1,324 passengers. Each axle on the train has it's own 285 Kw (387.6 hp) AC induction motor giving a 16 car train with 64 electric motors a total of 18.24 MW (24,460 hp), more than three top fuel dragsters.
The 640 Tonne train is controlled by an Automatic Train Control (ATC) system that ensures the train arrives at each station with accuracy down to the second. The ATC sets the acceleration and braking rates with a maximum Acel rate of 1.92 km/h/s which allows the Bullet train to accelerate from standstill to 300km in just 2.5 minutes.
The JR-500 ATC also uses electricity to brake all 640 tonnes down from 300 km/h at a controlled and predictable deceleration rate. Since 1984 all Shinkansen trains have used axial flux eddy current disc brakes. These work along the same lines as an eddy current dyno where a steel brake rotor has electromagnets facing it that when energised induce eddy currents in the rotor which generates electromagnetic friction. With the only moving part being the rotor and no wear and tear from mechanical friction, eddy current brakes have proved increadibly reliable and no doubt contribute to the 100% safety record acheieved by the Shinkansen rail system. Since 2007 all new Bullet trains have moved to regenerative braking that uses the main traction motors which will increase overall system efficiency.
tsport100 at 2:40 AM