Development of PWM converter with large capacity for electric railway substation

A new type DC electric railway system is under development for high speed and mass transportation in Japan. This system needs large power conversion stations consisting of PWM converters on the ground to cope with magnetic disturbance. In this system, the PWM converter needs to control the DC feeding voltage of 1,500 V at the error rate of 0.5% or less to suppress magnetic disturbance. This paper describes the PWM converter for the DC electric railway system, with emphasis placed on its control methods and characteristics.