Takamasa Hori

GTO Inverter for AC Traction Drives

A 600-kVA capacity GTO inverter for traction drives has been developed using 2500-V/1000-A gate turn-off (GTO) thyristors, and running tests have been carried out. To utilize the advantages of GTO thyristors, circuit inductance of both main loops and snubber loops were minimized in order to decrease overvoltage applied to GTO thyristors after turn-off. Appropriate protection systems for the GTO inverter against commutation failure and overcurrent in traction motors were developed. Running tests for an electric car driven by the GTO inverter showed good control characteristics.

On-Board Optical Data Communications Network for Train Control

Recently, electronic control equipment has begun to be installed in trains. This equipment is being used to communicate control and status information to allow trains to be operated more efficiently and reliably. However, the use of such equipment causes an increase in the amount of control and monitor information generated on a train, which in turn causes an increase in the amount of wiring required to carry the information. Until now, monitor equipment data have been multiplexed, and metal wire cables have been used, to reduce the amount and weight of wiring used [1].