Thyristor chopper control using magnetic pulse width modulator

The thyristor chopper control technique for electric vehicles using a magnetic pulse width modulator is described and the chopper control system for Japan´s nation-wide Shinkansen [1] Train car is given as an example. The operating mechanism of a newly-developed magnetic pulse width modulator and its functions are analyzed. Using them to the best advantage has made it possible to integrate the principal functions for the chopper control, whereby a high degree of simplification of the control system has been attained. The excellent stability of the modulator to electrical noise signals, unavoidable to electric vehicles, is noteworthy. Applications of the technique to battery-operated locomotives and battery-operated fork-lift trucks are also mentioned.