Fully digitized traction motor controller for high power AC electric locomotives

A fully digitized traction motor controller, utilizing microprocessors, was developed for high power AC electric locomotives (continuous rated output: 3,000 kW). The control system is composed of a time discrete system (software implementation), a time continuous system (controlled system), a holder (thyristor rectifier bridge) and a sampler. The entire control system was analyzed and synthesized in a frequency domain. As a result, stable and rapid response control characteristics were achieved throughout the running range of the locomotives. This paper describes the controller construction and analyses of the control system.